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XC9235/XC9236/XC9237 Series
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
ETR0514-011a
The XC9235/XC9236/XC9237 series is a group of synchronous-rectification type DC/DC converters with a built-in 0.42 P-channel MOS driver transistor and 0.52 N-channel MOS switching transistor, designed to allow the use of ceramic capacitors. Operating voltage range is from 2.0V to 6.0V (A C types), 1.8V to 6.0V (D G types). For the D/F types which have a reference voltage of 0.8V (accuracy: 2.0%), the output voltage can be set from 0.9V by using two external resistors. The A/B/C/E/G types have a fixed output voltage from 0.8V to 4.0V in increments of 0.05V (accuracy: 2.0%). The device provides a high efficiency, stable power supply with an output current of 600mA to be configured using only a coil and two capacitors connected externally. With the built-in oscillator, either 1.2MHz or 3.0MHz can be selected for suiting to your particular application. As for operation mode, the XC9235 series is PWM control, the XC9236 series is automatic PWM/PFM switching control and the XC9237 series can be manually switched between the PWM control mode and the automatic PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads (from light load to heavy load). The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0 A or less. The B/F/G types have a high speed soft-start as fast as 0.25ms in typical for quick turn-on. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel MOS driver transistor is forced OFF when input voltage becomes 1.4V or lower. The B to G types integrate CL discharge function which enables the electric charge at the output capacitor CL to be discharged via the internal discharge switch located between the LX and VSS pins. When the devices enter stand-by mode, output voltage quickly returns to the VSS level as a result of this function. Three types of package SOT-25 (A/B/C types only), USP-6C, and 0.4mm low height USP-6EL (A/B/C types only) are available.
GENERAL DESCRIPTION
GreenOperation Compatible
APPLICATIONS
Mobile phones, Smart phones Bluetooth headsets Mobile WiMAX PDAs, MIDs, UMPCs Portable game consoles Digital cameras, Camcorders MP3 Players, Portable Media Players Notebook computers
FEATURES
Driver Transistor Built-In Input Voltage Output Voltage High Efficiency Output Current Oscillation Frequency Maximum Duty Cycle Control Methods : 0.42 P-ch driver transistor 0.52 N-ch switch transistor : 2.0V ~ 6.0V (A/B/C types) 1.8V ~ 6.0V (D/E/F/G types) : 0.8V ~ 4.0V : 92% (TYP.) : 600mA : 1.2MHz, 3.0MHz (+15%) : 100% : PWM (XC9235) PWM/PFM Auto (XC9236) PWM/PFM Manual (XC9237) : Current Limiter Circuit Built-In (Constant Current & Latching) CL Discharge (B/C/D/E/F/G types) High Speed Soft Start (B/F/G type) : Low ESR Ceramic Capacitor : SOT-25 (A/B/C types only), USP-6C USP-6EL(A/B/C types only) : EU RoHS Compliant, Pb Free
TYPICAL APPLICATION CIRCUIT
XC9235/XC9236/XC9237 A/B/C/E/G types (Output Voltage Fixed)
Function
Capacitor Packages Environmentally Friendly
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs. Output Current XC9235/XC9236/XC9237 D/F types (Output Voltage Externally Set)
Efficiency: EFFI (%) Efficency:EFFI(%)
100 90 80 70 60 50 40 30 20 10 0 0.1 1 10 100 1000 Output Current:IOUT(mA)
2.4V VIN= 4.2V 3.6V PWM Control VIN= 4.2V 3.6V 2.4V
fOSC=1.2MHz, VOUT=1.8V
PWM/PFM Automatic Sw itching Control
1/33
XC9235/XC9236/XC9237 Series
PIN CONFIGURATION
Lx VOUT
5
4
VIN VSS 6 5 1 2 3 Lx VSS VOUT (FB) VIN VSS 6 5 1 2 3 Lx VSS VOUT
CE/MODE 4
CE/MODE 4
1
VIN
2
VSS
3
CE/MODE
SOT-25 (Top View)
USP-6C (BOTTOM VIEW)
USP-6EL (BOTTOM VIEW)
* Please short the VSS pin (No. 2 and 5). * The dissipation pad for the USP-6C package should be solder-plated in recommended mount pattern and metal masking so as to enhance mounting strength and heat release. If the pad needs to be connected to other pins, it should be connected to the VSS (No. 5) pin.
PIN ASSIGNMENT
PIN NUMBER SOT-25 USP-6C/USP-6EL 1 6 2 2, 5 3 4 4 5 3 1 PIN NAME VIN VSS CE / MODE VOUT
FB
FUNCTION Power Input Ground High Active Enable / Mode Selection Pin Fixed Output Voltage Pin (A/B/C/E/G types) Output Voltage Sense Pin (D/F types) Switching Output
Lx
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XC9235/XC9236/XC9237
Series
PRODUCT CLASSIFICATION
Ordering Information
XC9235 XC9236 XC9237 DESIGNATOR
*1 *1 *1
Fixed PWM control PWM / PFM automatic switching control Fixed PWM control PWM / PFM automatic switching manual selection SYMBOL A B C E G D F DESCRIPTION VIN 2.0V, No CL discharge, Low speed soft-start VIN 2.0V, CL discharge, High speed soft-start VIN 2.0V, CL discharge, Low speed soft-start VIN 1.8V, CL discharge, Low speed soft-start VIN 1.8V, CL discharge, High speed soft-start VIN 1.8V, CL discharge, Low speed soft-start VIN 1.8V, CL discharge, High speed soft-start Output voltage options e.g. VOUT=2.8V =2, =8 VOUT=2.85V =2, =L 0.05V increments: 0.05=A, 0.15=B, 0.25=C, 0.35=D, 0.45=E, 0.55=F, 0.65=H, 0.75=K, 0.85=L, 0.95=M Reference voltage is fixed in 0.8V =0, =8 1.2MHz 3.0MHz SOT-25 (*3) SOT-25 (Halogen & Antimony free) (*3) USP-6C USP-6C (Halogen & Antimony free) (*4) USP-6EL (Halogen & Antimony free) (*5)
DESCRIPTION
Fixed Output voltage (VOUT) Functional selection
Adjustable Output voltage (FB) Functional selection
Fixed Output Voltage (VOUT) Adjustable Output Voltage (FB) Oscillation Frequency
08 ~ 40
08 C D MR
-
Packages (*2) Taping Type
MR-G ER ER-G 4R-G
(*1) (*2)
(*3) (*4) (*5)
The "-G" suffix indicates that the products are Halogen and Antimony free as well as being fully RoHS compliant. The device orientation is fixed in its embossed tape pocket. For reverse orientation, please contact your local Torex sales office or representative. (Standard orientation: R- , Reverse orientation: L- ) SOT-25 package is available for the A/B/C series only. For Halogen & Antimony Free, the D/E/F/G series is under development. For the USP-6EL package, the D/E/F/G series is under development.
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XC9235/XC9236/XC9237 Series
BLOCK DIAGRAM
XC9235 / XC9236 / XC9237 XC9235/XC9236/XC9237 AA Series
Phase Compensation
XC9235 / XC9236 XC9235/XC9236/XC9237/ XC9237 B,C,E,G B/C/E/G Series
Phase Compensation
VOUT
R2
Current Feedback Current Limit
CFB Error Amp. FB
Logic
VOUT
R2
Synch Buffer Drive
Current Feedback Current Limit
CFB Error Amp. FB
Logic
PWM Comparator
PWM Comparator Synch Buffer Drive
R1
Lx VIN
R1
VSHORT
Lx
VIN
Vref with Soft Start, CE
VSHORT
PWM/PFM Selector
Vref with Soft Start, CE
PWM/PFM Selector
CE/
Ramp Wave Generator OSC Ramp Wave Generator OSC
UVLO Cmp UVLO
UVLO Cmp UVLO
VSS
R3
VSS
CE/MODE Control Logic
R3
R4
CE/MODE
R4
CE/MODE Control Logic
CE/MODE
XC9235/XC9236/XC9237 XC9235 / XC9236 / XC9237 D,F D/F Series
Phase Compensation
FB
Error Amp.
PWM Comparator
Current Feedback Current Limit
Logic
Synch Buffer Drive
Lx
VIN
Vref with Soft Start, CE
VSHORT
PWM/PFM Selector
CE/
Ramp Wave Generator OSC
UVLO Cmp UVLO
VSS
R3
R4
CE/MODE Control Logic
CE/MODE
NOTE: The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "L" level inside, and XC9235 series chooses only PWM control. The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "H" level inside, and XC9236 series chooses only PWM/PFM automatic switching control. Diodes inside the circuit are ESD protection diodes and parasitic diodes.
ABSOLUTE MAXIMUM RATINGS
PARAMETER VIN Pin Voltage Lx Pin Voltage VOUT Pin Voltage FB Pin Voltage CE / MODE Pin Voltage Lx Pin Current SOT-25 Power Dissipation USP-6C (*Ta=25) USP-6EL Operating Temperature Range Storage Temperature Range SYMBOL VIN VLx VOUT VFB VCE ILx Pd Topr Tstg RATINGS - 0.3 ~ 6.5 - 0.3 ~ VIN + 0.3 - 0.3 ~ 6.5 - 0.3 ~ 6.5 - 0.3 ~ 6.5 1500 250 100 100 - 40 ~ + 85 - 55 ~ + 125 6.5V Ta=25 UNIT V V V V V mA mW
O O
C C
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XC9235/XC9236/XC9237
Series
ELECTRICAL CHARACTERISTICS
XC9237A18Cxx, VOUT=1.8V, fOSC=1.2MHz, Ta=25
PARAMETER Output Voltage Operating Voltage Range Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency
(*2)
SYMBOL VOUT VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI RLxH RLxH RLxL RLxL ILeakH ILeakL
CONDITIONS When connected to external components, VIN=VCE=5.0V, IOUT=30mA VIN=VOUT(E)+2.0V, VCE=1.0V, (*9) When connected to external components VCE =VIN, VOUT=0V, (*1, *11) Voltage which Lx pin holding "L" level VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V 1.1V VIN=5.0V, VCE=0V, VOUT=VOUT(E)
MIN. 1.764 2.0 600 1.00 1020 120
TYP. 1.800 1.40 15 0 1200 160 200
MAX. 1.836 6.0 1.78 33 1.0 1380 200
UNIT V V mA V A A kHz mA %
CIRCUIT
When connected to external components, VIN=VOUT(E)+2.0V, VCE =1.0V, IOUT=100mA When connected to external components, (*12) VIN=VOUT(E)+2.0V, VCE =VIN, IOUT=1mA VCE=VIN=(C-1), IOUT=1mA
(*12)
VIN=VCE=5.0V, VOUT=VOUT(E)
0.9V
100 (*8)
92 0.35 0.42 0.45 0.52 0.01 0.01 1050 100 -
0 0.55 0.67 0.66 0.77 1.0 1.0 1350 6.0 0.25
% % %
Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 Lx SW "H" Leak Current Lx SW "L" Leak Current
(*10) (*5) (*5)
VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V When connected to external components, VCE=VIN=VOUT(E)+1.2V, IOUT=100mA (*3) VIN=VCE=5.0V, VOUT=0V, ILx=100mA VIN=VCE=3.6V, VOUT=0V, ILx=100mA VIN=VCE=5.0V VIN=VCE=3.6V
(*4) (*4) (*3)
A A mA ppm/ V V
VIN=VOUT=5.0V, VCE=0V, Lx=0V VIN=VOUT=5.0V, VCE=0V, Lx=5.0V
Current Limit Output Voltage Temperature Characteristics CE "H" Voltage CE "L" Voltage
ILIM VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V VOUT/ IOUT=30mA, -40 Topr 85 (VOUT Topr) VOUT=0V, Applied voltage to VCE, VCEH (*11) Voltage changes Lx to "H" level VOUT=0V, Applied voltage to VCE , VCEL (*11) Voltage changes Lx to "L" level VPWMH
900 0.65 VSS
PWM "H" Level Voltage
When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes 1020 kHz fOSC 1380kHz When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes fOSC 1020kHz VIN=VCE=5.0V, VOUT=0V VIN=5.0V, VCE=0V, VOUT=0V When connected to external components, VCE=0V VIN, IOUT=1mA VIN=VCE=5.0V, VOUT=0.8 VOUT(E), (*7) Short Lx at 1 resistance Sweeping VOUT, VIN=VCE=5.0V, Short Lx at 1 resistance, VOUT voltage which Lx becomes "L" level within 1ms
-
-
VIN - 1.0
V
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time Latch Time Short Protection Threshold Voltage
VPWML ICEH ICEL tSS tLAT VSHORT
VIN - 0.25 - 0.1 - 0.1 0.5 1.0 0.675
1.0 0.900
0.1 0.1 2.5 20.0 1.150
V A A ms ms V
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VOUT with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions.
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XC9235/XC9236/XC9237 Series
ELECTRICAL CHARACTERISTICS (Continued)
XC9237A18Dxx, VOUT=1.8V, fOSC=3.0MHz, Ta=25
PARAMETER Output Voltage Operating Voltage Range Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency SYMBOL VOUT VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI VIN=VOUT(E)+2.0V, VCE=1.0V, (*9) When connected to external components VCE=VIN, VOUT=0V, (*1,*11) Voltage which Lx pin holding "L" level VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V 1.1V VIN=5.0V, VCE=0V, VOUT=VOUT(E) CONDITIONS When connected to external components, VIN=VCE=5.0V, IOUT=30mA MIN. 1.764 2.0 600 1.00 2550 170 0.9V 100 900 0.65 VSS TYP. 1.800 1.40 21 0 3000 220 200 86 0.35 0.42 0.45 0.52 0.01 0.01 1050 100 MAX. 1.836 6.0 1.78 35 1.0 3450 270 300 0 0.55 0.67 0.66 0.77 1.0 1.0 1350 6.0 0.25 VIN - 1.0 UNIT V V mA V A A kHz mA % % % % CIRCUIT
When connected to external components, VIN=VOUT(E)+2.0V, VCE=1.0V, IOUT=100mA When connected to external components, (*12) VIN=VOUT(E)+2.0V, VCE=VIN, IOUT=1mA VCE=VIN=(C-1), IOUT=1mA
(*12)
VIN=VCE=5.0V, VOUT=VOUT(E)
Lx SW "H" ON Resistance 1 RLxH Lx SW "H" ON Resistance 2 RLxH Lx SW "L" ON Resistance 1 RLxL Lx SW "L" ON Resistance 2 RLxL (*5) Lx SW "H" Leak Current ILeakH (*5) Lx SW "L" Leak Current ILeakL (*10) Current Limit ILIM Output Voltage VOUT/ IOUT=30mA, -40 Topr 85 Temperature Characteristics (VOUT Topr) VOUT=0V, Applied voltage to VCE, CE "H" Voltage VCEH (*11) Voltage changes Lx to "H" level VOUT=0V, Applied voltage to VCE, CE "L" Voltage VCEL (*11) Voltage changes Lx to "L" level PWM "H" Level Voltage VPWMH
VIN=VCE=5.0V, VOUT=VOUT(E) 0.1V When connected to external components, VCE=VIN VOUT(E)+1.2V, IOUT=100mA (*3) VIN=VCE=5.0V, VOUT =0V, ILx=100mA (*3) VIN=VCE=3.6V, VOUT =0V, ILx=100mA (*4) VIN=VCE=5.0V (*4) VIN=VCE=3.6V VIN=VOUT=5.0V, VCE=0V, Lx=0V VIN=VOUT=5.0V, VCE=0V, Lx=5.0V (*8) VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V
A A mA ppm/ V V V
When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes 2550kHz fOSC 3450kHz When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes fOSC 2550kHz VIN=VCE=5.0V, VOUT=0V VIN=5.0V, VCE=0V, VOUT=0V When connected to external components, VCE=0V VIN, IOUT=1mA VIN=VCE=5.0V, VOUT=0.8 VOUT(E), (*7) Short Lx at 1 resistance Sweeping VOUT, VIN=VCE=5.0V, Short Lx at 1 resistance, VOUT voltage which Lx becomes "L" level within 1ms
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time Latch Time Short Protection Threshold Voltage
VPWML ICEH ICEL tSS tLAT VSHORT
VIN - 0.25 - 0.1 - 0.1 0.5 1.0 0.675
0.9 0.900
0.1 0.1 2.5 20 1.150
V A A ms ms V
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VOUT with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions.
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XC9235/XC9236/XC9237
Series
ELECTRICAL CHARACTERISTICS (Continued)
XC9237B(C)(E)(G)18Cxx, VOUT=1.8V, fOSC=1.2MHz, Ta=25
PARAMETER Output Voltage Operating Voltage Range (B/C series) Operating Voltage Range (E/G series) Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency
(*2)
SYMBOL VOUT VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI RLxH RLxH RLxL RLxL ILeakH
CONDITIONS When connected to external components, VIN=VCE=5.0V, IOUT=30mA
MIN. 1.764 2.0 1.8
TYP. 1.800 1.40 15 0 1200 160 200 92 0.35 0.42 0.45 0.52 0.01 1050 100 -
MAX. 1.836 6.0 6.0 1.78 33 1.0 1380 200 0 0.55 0.67 0.66 0.77 1.0 1350 6.0 0.25 VIN - 1.0
UNIT V V mA V A A kHz mA % % % %
CIRCUIT
VIN=VOUT(E)+2.0V, VCE=1.0V, (*9) When connected to external components (*14) VCE =VIN, VOUT=VOUT(E) 0.5V (*1, *11) Voltage which Lx pin holding "L" level VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V VIN=5.0V, VCE=0V, VOUT=VOUT(E) 1.1V When connected to external components, VIN=VOUT(E)+2.0V, VCE =1.0V, IOUT=100mA When connected to external components, (*12) VIN=VOUT(E)+2.0V, VCE =VIN, IOUT=1mA (*12) VCE=VIN=(C-1), IOUT=1mA VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V When connected to external components, VCE=VIN=VOUT(E)+1.2V, IOUT=100mA (*3) VIN=VCE=5.0V, VOUT (E) 0.9V , ILx=100mA VIN=VCE=3.6V, VOUT (E) VIN=VCE=5.0V VIN=VCE=3.6V
(*4) (*4)
600 1.00 1020 120 100 -
Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 Lx SW "H" Leak Current
(*10) (*5)
0.9V , ILx=100mA
(*3)
A mA ppm/ V V V
VIN=VOUT=5.0V, VCE=0V, Lx=0V
(*8)
Current Limit Output Voltage Temperature Characteristics CE "H" Voltage CE "L" Voltage PWM "H" Level Voltage
ILIM VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V VOUT/ I =30mA, -40 Topr 85 (VOUT Topr) OUT VOUT= VOUT(E)x0.9V, Applied voltage to VCE, VCEH (*11) Voltage changes Lx to "H" level VOUT= VOUT(E)x0.9V, Applied voltage to VCE , VCEL (*11) Voltage changes Lx to "L" level VPWMH
(*6)
900 0.65 VSS -
When connected to external components, IOUT=1mA , Voltage which oscillation frequency becomes 1020 (*13) kHz fOSC 1380kHz
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time (B/G Series) Soft Start Time (C/E Series) Latch Time Short Protection Threshold Voltage (B/C Series) Short Protection Threshold Voltage (E/G Series) CL Discharge
VPWML ICEH ICEL tSS tSS tLAT VSHORT VSHORT RDCHG
When connected to external components, IOUT=1mA , Voltage which oscillation frequency becomes fOSC (*13) 1020kHz VIN=VCE=5.0V, VOUT= VOUT(E)x0.9V VIN=5.0V, VCE=0V, VOUT= VOUT(E)x0.9V When connected to external components, VCE=0V VIN, IOUT=1mA When connected to external components, VCE=0V VIN, IOUT=1mA VIN=VCE=5.0V, VOUT=0.8 VOUT(E), (*7) Short Lx at 1 resistance Sweeping VOUT, VIN=VCE=5.0V, Short Lx at 1 resistance, VOUT voltage which Lx becomes "L" level within 1ms (*11) VIN=VCE=5.0V, The VOUT at Lx="Low" while decreasing VOUT from VOUT (E)x0.4V
(*6)
VIN - 0.25 - 0.1 - 0.1 0.5 1.0 0.675 0.338 200
0.25 1.0 0.900 0.450 300
0.1 0.1 0.40 2.5 20.0 1.150 0.563 450
V A A ms ms ms V V
VIN=5.0V, LX=5.0V, VCE=0V, VOUT=open
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT VIN VCE NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VOUT with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions. *14: VIN is applied when VOUT (E) x 0.5V becomes more than VIN.
7/33
XC9235/XC9236/XC9237 Series
ELECTRICAL CHARACTERISTICS (Continued)
XC9237B(C)(E)(G)18Dxx, VOUT=1.8V, fOSC=3.0MHz, Ta=25
PARAMETER Output Voltage Operating Voltage Range (B/C series) Operating Voltage Range (E/G series) Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 (*5) Lx SW "H" Leak Current (*10) Current Limit Output Voltage Temperature Characteristics CE "H" Voltage CE "L" Voltage PWM "H" Level Voltage SYMBOL VOUT VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI VIN=VOUT(E)+2.0V, VCE=1.0V, (*9) When connected to external components (*14) , VCE=VIN, VOUT=VOUT(E) 0.5V (*1,*11) Voltage which Lx pin holding "L" level VIN=VCE=5.0V, VOUT=VOUT(E) 1.1V VIN=5.0V, VCE=0V, VOUT=VOUT(E) 1.1V When connected to external components, VIN=VOUT(E)+2.0V, VCE=1.0V, IOUT=100mA When connected to external components, (*12) VIN=VOUT(E)+2.0V, VCE=VIN, IOUT=1mA (*12) VCE=VIN=(C-1), IOUT=1mA VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V VIN=VCE=5.0V, VOUT=VOUT(E) 0.1V When connected to external components, VCE=VIN VOUT(E)+1.2V, IOUT=100mA (*3) VIN=VCE=5.0V, VOUT=VOUT(E)x0.9V, ILx=100mA (*3) VIN=VCE=3.6V, VOUT=VOUT(E)x0.9V, ILx=100mA (*4) VIN=VCE=5.0V (*4) VIN=VCE=3.6V VIN=VOUT=5.0V, VCE=0V, Lx=0V (*8) VIN=VCE=5.0V, VOUT=VOUT(E) 0.9V CONDITIONS When connected to external components, VIN=VCE=5.0V, IOUT=30mA MIN. 1.764 2.0 1.8 600 1.00 2550 170 100 900 0.65 VSS TYP. 1.800 1.40 21 0 3000 220 200 86 0.35 0.42 0.45 0.52 0.01 1050 100 MAX. 1.836 6.0 6.0 1.78 35 1.0 3450 270 300 0 0.55 0.67 0.66 0.77 1.0 1350 6.0 0.25 VIN - 1.0 UNIT V V mA V A A kHz mA % % % % CIRCUIT
RLxH RLxH RLxL RLxL ILeakH ILIM VOUT/ I =30mA, -40 Topr 85 (VOUT Topr) OUT VOUT=VOUT(E)x0.9V, Applied voltage to VCE, VCEH (*11) Voltage changes Lx to "H" level VOUT=VOUT(E)x0.9V, Applied voltage to VCE, VCEL (*11) Voltage changes Lx to "L" level VPWMH
A mA ppm/ V V V
When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes 2550kHz fOSC 3450kHz When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency (*13) becomes fOSC 2550kHz VIN=VCE=5.0V, VOUT=VOUT(E)x0.9V VIN=5.0V, VCE=0V, VOUT=VOUT(E)x0.9V When connected to external components, VCE=0V VIN, IOUT=1mA When connected to external components, VCE=0V VIN, IOUT=1mA VIN=VCE=5.0V, VOUT=0.8 VOUT(E), (*7) Short Lx at 1 resistance Sweeping VOUT, VIN=VCE=5.0V, Short Lx at 1 resistance, VOUT voltage which Lx becomes "L" level within 1ms VIN=VCE=5.0V, The VOUT at Lx="Low" decreasing VOUT from VOUT (E)x0.4V
(*11)
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time (B/G Series) Soft Start Time (C/E Series) Latch Time Short Protection Threshold Voltage (B/C Series) Short Protection Threshold Voltage (E/G Series) CL Discharge
VPWML ICEH ICEL tSS tSS tLAT VSHORT VSHORT RDCHG
VIN - 0.25 - 0.1 - 0.1 0.5 1.0 0.675 0.338 200
0.32 0.9 0.900 0.450 300
0.1 0.1 0.50 2.5 20 1.150 0.563 450
V A A ms ms ms V V
while
VIN=5.0V, LX=5.0V, VCE=0V, VOUT=open
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT VIN VCE NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VOUT with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions. *14: VIN is applied when VOUT (E) x 0.5V becomes more than VIN.
8/33
XC9235/XC9236/XC9237
Series
ELECTRICAL CHARACTERISTICS (Continued)
XC9237D(F)08Cxx, FB Type, fOSC=1.2MHz, Ta=25
PARAMETER FB Voltage Operating Voltage Range Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency
(*2)
SYMBOL VFB VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI RL H RL H RL L RL L ILeakH ILIM VOUT/ (VOUT Topr) VCEH VCEL VPWMH
CONDITIONS VIN = VCE =5.0V, The VFB at Lx= High" decreasing FB pin voltage from 0.9V.
(*11)
MIN. while 0.784 1.8
TYP. 0.800 1.40 15 0 1200 160 200 92 0.35 0.42 0.45 0.52 0.01 1050 100 -
MAX. 0.816 6.0 1.78 1.0 1380 200 0 0.55 0.67 0.66 0.77 1.0 1350 6.0 0.25 VIN - 1.0
UNIT V V mA V A A kHz mA % % % %
CIRCUIT
VIN=3.2V, VCE=1.0V (*9) When connected to external components VCE = VIN , VFB = 0.4V, (*1,*11) Voltage which Lx pin holding "L" level VIN =VCE=5.0V, VFB= 0.88V VIN =5.0V, VCE=0V, VFB= 0.88V When connected to external components, VIN = 3.2V, VCE=1.0V, IOUT=100mA When connected to external components, (*12) VIN =3.2V, VCE = VIN , IOUT=1mA (*12) VCE= VIN =2.0V IOUT=1mA VIN = VCE =5.0V, VFB = 0.72V VIN = VCE =5.0V, VFB = 0.88V When connected to external components, VCE = VIN 2.4V, IOUT = 100mA (*3) VIN = VCE = 5.0V, VFB = 0.72V,ILX = 100mA (*3) VIN = VCE = 3.6V, VFB = 0.72V,ILX = 100mA (*4) VIN = VCE = 5.0V (*4) VIN = VCE = 3.6V VIN = VFB = 5.0V, VCE = 0V, LX= 0V (*8) VIN = VCE= 5.0V, VFB = 0.72V IOUT =30mA -40 Topr 85 VFB =0.72V, Applied voltage to VCE, (*11) Voltage changes Lx to "H" level VFB =0.72V, Applied voltage to VCE, (*11) Voltage changes Lx to "L" level When connected to external components, (*6) IOUT=1mA , Voltage which oscillation frequency becomes 1020kHz fOSC 1380kHz
(*13)
600 1.00 1020 120 100 900 0.65 VSS VIN 0.25 - 0.1 - 0.1 0.5 1.0 0.15 200
Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 (*5) Lx SW "H" Leak Current (*10) Current Limit Output Voltage Temperature Characteristics CE "H" Voltage CE "L" Voltage PWM "H" Level Voltage
A mA ppm/ V V V
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time (D series) Soft Start Time (F series) Latch Time Short Protection Threshold Voltage CL Discharge
VPWML ICEH ICEL tSS tLAT VSHORT RDCHG
When connected to external components, (*6) IOUT=1mA , Voltage which oscillation (*13) frequency becomes fOSC 1020kHz VIN = VCE =5.0V, VFB =0.72V VIN =5.0V, VCE = 0V, VFB =0.72V When connected to external components, VCE = 0V VIN , IOUT=1mA VIN=VCE=5.0V, VFB=0.64, Short Lx at 1 (*7) resistance (*11) while VIN = VCE =5.0V, The VFB at Lx="Low" decreasing FB pin voltage from 0.4V. VIN = 5.0V ,LX = 5.0V, VCE = 0V, VFB= open
1.0 0.25 0.200 300
0.1 0.1 2.5 0.40 20.0 0.25 450
V A A ms ms V
Test conditions: VOUT=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT VIN VCE NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VFB with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions.
9/33
XC9235/XC9236/XC9237 Series
ELECTRICAL CHARACTERISTICS (Continued)
XC9237D(F)08Dxx, FB, fOSC=3.0MHz, Ta=25
PARAMETER FB Voltage Operating Voltage Range Maximum Output Current UVLO Voltage Supply Current Stand-by Current Oscillation Frequency PFM Switching Current PFM Duty Limit Maximum Duty Cycle Minimum Duty Cycle Efficiency
(*2)
SYMBOL VFB VIN IOUTMAX VUVLO IDD ISTB fOSC IPFM DTYLIMIT_PFM DTYMAX DTYMIN EFFI RL H RL H RL L RL L ILeakH ILIM VOUT/ (VOUT Topr) VCEH VCEL VPWMH
CONDITIONS VIN = VCE =5.0V, The VFB at Lx= High" decreasing FB pin voltage from 0.9V.
(*11)
MIN. while 0.784 1.8
TYP. 0.800 1.40 21 0 3000 220 200
MAX. 0.816 6.0 1.78 35 1.0 3450 270 300 0 0.55 0.67 0.66 0.77 1.0 1350 6.0 0.25 VIN - 1.0
UNIT V V mA V A A kHz mA % % % %
CIRCUIT
VIN=3.2V, VCE=1.0V (*9) When connected to external components VCE = VIN , VFB = 0.4V , (*1, *11) Voltage which Lx pin holding "L" level VIN =VCE=5.0V, VFB= 0.88V VIN =5.0V, VCE=0V, VFB= 0.88V When connected to external components, VIN = 3.2V, VCE=1.0V, IOUT=100mA When connected to external components, (*12) VIN =3.2V, VCE = VIN , IOUT=1mA VCE= VIN =2.2V IOUT=1mA
(*12)
600 1.00 2550 170
VIN = VCE =5.0V, VFB = 0.72V VIN = VCE =5.0V, VFB = 0.88V When connected to external components, VCE = VIN 2.4V, IOUT = 100mA (*3) VIN = VCE = 5.0V, VFB = 0.72V,ILX = 100mA (*3) VIN = VCE = 3.6V, VFB = 0.72V,ILX = 100mA (*4) VIN = VCE = 5.0V (*4) VIN = VCE = 3.6V VIN = VFB = 5.0V, VCE = 0V, LX= 0V (*8) VIN = VCE= 5.0V, VFB = 0.72V IOUT =30mA -40 Topr 85 VFB =0.72V , VCE, (*11) Voltage changes Lx to "H" level VFB =0.72V, VCE, (*11) Voltage changes Lx to "L" level When connected to external components, (*6) IOUT = 1mA , Voltage which oscillation frequency (*13) becomes 2550kHz fOSC 3450kHz When connected to external components, (*6) IOUT = 1mA , Voltage which oscillation frequency (*13) becomes fOSC 2550kHz VIN = VCE =5.0V, VFB =0.72V VIN =5.0V, VCE = 0V, VFB =0.72V When connected to external components, VCE = 0V VIN , IOUT=1mA VIN = VCE = 5.0V, VFB = 0.64, (*7) Short Lx at 1 resistance (*11) VIN = VCE =5.0V, The VFB at Lx="Low" while decreasing FB pin voltage from 0.4V. VIN = 5.0V ,LX = 5.0V ,VCE = 0V ,VFB= open
100 900 0.65 VSS VIN 0.25 - 0.1 - 0.1 0.5 1.0 0.15 200
86 0.35 0.42 0.45 0.52 0.01 1050 100 -
Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 (*5) Lx SW "H" Leak Current (*10) Current Limit Output Voltage Temperature Characteristics CE "H" Voltage CE "L" Voltage PWM "H" Level Voltage
A mA ppm/ V V V
PWM "L" Level Voltage CE "H" Current CE "L" Current Soft Start Time (D series) Soft Start Time (F series) Latch Time Short Protection Threshold Voltage CL Discharge
VPWML ICEH ICEL tSS tLAT VSHORT RDCHG
1.0 0.25 0.200 300
0.1 0.1 2.5 0.40 20.0 0.25 450
V A A ms ms V
Test conditions: VOUT=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT VIN VCE NOTE: *1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage output current ) ( input voltage input current) } 100 *3: ON resistance ( )= (VIN - Lx pin measurement voltage) 100mA *4: R&D value *5: When temperature is high, a current of approximately 10 A (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH. *7: Time until it short-circuits VFB with GND via 1 of resistor from an operational state and is set to Lx=0V from current limit pulse generating. *8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: "H"=VIN~VIN-1.2V, "L"=+0.1V~-0.1V *12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control's functions. *13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series' functions.
10/33
XC9235/XC9236/XC9237
Series
ELECTRICAL CHARACTERISTICS (Continued)
PFM Switching Current (IPFM) by Oscillation Frequency and Setting Voltage
(mA) SETTING VOLTAGE VOUT(E) 1.2V 1.2VVOUT(E) 1.75V 1.8VVOUT(E) MIN. 140 130 120 1.2MHz TYP. 180 170 160 MAX. 240 220 200 MIN. 190 180 170 3.0MHz TYP. 260 240 220 MAX. 350 300 270
Input Voltage (VIN) for Measuring PFM Duty Limit (DTYLIMIT_PFM)
fOSC C-1
Minimum operating voltage is 2.0V. ex.) Although when VOUT(E) is 1.2V and fOSC is 1.2MHz, (C-1) should be 1.7V, (C-1) becomes 2.0V for the minimum operating voltage 2.0V.
1.2MHz VOUT(E)+0.5V
3.0MHz VOUT(E)+1.0V
Soft-Start Time, Setting Voltage
SERIES fOSC 1.2MHz 1.2MHz 1.2MHz 1.2MHz XC9236B(G) XC9235B(G)/ XC9236B(G)/XC9237B(G) 1.2MHz 1.2MHz 3.0MHz 3.0MHz
XC9235B(G)/9236B(G)/9237B(G) Series only
SETTING VOLTAGE 0.8V OUT(E)<1.5 1.5V OUT(E)<1.8 1.8V OUT(E)<2.5 2.5V OUT(E)<4.0 0.8V OUT(E)<2.5 2.5V OUT(E)<4.0 0.8V OUT(E)<1.8 1.8V OUT(E)<4.0 MIN. TYP. 250 320 280 320 280 320 280 320
(
s)
MAX. 400 500 400 500 400 500 400 500
XC9235B(G)/XC9237B(G)
11/33
XC9235/XC9236/XC9237 Series
TYPICAL APPLICATION CIRCUIT
XC9235/9236/9237A, B, C, E, G Series (Output Voltage Fixed)
VOUT 600mA L Lx VSS CL (ceramic) VOUT VIN VSS CE/ MODE CIN (ceramic) CE/MODE VIN
fOSC=3.0MHz L: 1.5 H CIN: 4.7 F CL: 10 F fOSC=1.2MHz L: 4.7 H CIN: 4.7 F CL: 10 F
(NR3015, TAIYO YUDEN) (Ceramic) (Ceramic) (NR4018, TAIYO YUDEN) (Ceramic) (Ceramic)
XC9235/9236/9237D, F Series (Output Voltage External Setting)
Output voltage can be set externally by adding two resistors to the FB pin. The output voltage is calculated by the RFB1 and RFB2 value. The total of RFB1 and RFB2 is usually selected less than 1M. VOUT=0.8 x (RFB1+RFB2)/RFB2 The value of the phase compensation speed-up capacitor CFB is calculated by the formula of fZFB = 1/(2x xCFB1xRFB1) with fZFB <10kHz. For optimization, fZFB can be adjusted in the range of 1kHz to 20kHz depending on the inductance L and the load capacitance CL which are used. Formula When RFB1=470k and RFB2=150k, VOUT1=0.8 x (470k+150k) / 150k=3.3V Example VOUT RFB1 (k ) (V) 0.9 100 1.2 150 1.5 130 1.8 300
RFB2 (k ) 820 300 150 240
CFB (pF) 150 100 220 150
VOUT (V) 2.5 3.0 3.3 4.0
RFB1 (k ) 510 330 470 120
RFB2 (k ) 240 120 150 30
CFB (pF) 100 150 100 470
12/33
XC9235/XC9236/XC9237
Series
OPERATIONAL DESCRIPTION
The XC9235/XC9236/XC9237 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output voltage adjustment resistors, P-channel MOS driver transistor, N-channel MOS switching transistor for the synchronous switch, current limiter circuit, UVLO circuit and others. (See the block diagram above.) The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the VOUT pin through split resistors, R1 and R2. Phase compensation is performed on the resulting error amplifier output, to input a signal to the PWM comparator to determine the turn-on time during PWM operation. The PWM comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp wave from the ramp wave circuit, and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle. This process is continuously performed to ensure stable output voltage. The current feedback circuit monitors the P-channel MOS driver transistor current for each switching operation, and modulates the error amplifier output signal to provide multiple feedback signals. This enables a stable feedback loop even when a low ESR capacitor such as a ceramic capacitor is used ensuring stable output voltage. The reference voltage source provides the reference voltage to ensure stable output voltage of the DC/DC converter. The ramp wave circuit determines switching frequency. The frequency is fixed internally and can be selected from 1.2MHz or 3.0MHz. Clock pulses generated in this circuit are used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal circuits. The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback voltage divided by the internal split resistors, R1 and R2. When a voltage lower than the reference voltage is fed back, the output voltage of the error amplifier increases. The gain and frequency characteristics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer. The current limiter circuit of the XC9235/XC9236/XC9237 series monitors the current flowing through the P-channel MOS driver transistor connected to the Lx pin, and features a combination of the current limit mode and the operation suspension mode. When the driver current is greater than a specific level, the current limit function operates to turn off the pulses from the Lx pin at any given timing. When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state. At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over current state. When the over current state is eliminated, the IC resumes its normal operation. The IC waits for the over current state to end by repeating the steps through . If an over current state continues for a few ms and the above three steps are repeatedly performed, the IC performs the function of latching the OFF state of the driver transistor, and goes into operation suspension mode. Once the IC is in suspension mode, operations can be resumed by either turning the IC off via the CE/MODE pin, or by restoring power to the VIN pin. The suspension mode does not mean a complete shutdown, but a state in which pulse output is suspended; therefore, the internal circuitry remains in operation. The current limit of the XC9235/XC9236/XC9237 series can be set at 1050mA at typical. Besides, care must be taken when laying out the PC Board, in order to prevent misoperation of the current limit mode. Depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid the effect of noise, the board should be laid out so that input capacitors are placed as close to the IC as possible.
13/33
XC9235/XC9236/XC9237 Series
OPERATIONAL DESCRIPTION (Continued)

The short-circuit protection circuit monitors the internal R1 and R2 divider voltage from the VOUT pin (refer to FB point in the block diagram shown in the previous page). In case where output is accidentally shorted to the Ground and when the FB point voltage decreases less than half of the reference voltage (Vref) and a current more than the ILIM flows to the Pch MOS driver transistor, the short-circuit protection quickly operates to turn off and to latch the driver transistor. For the D/E/F/G series, it does not matter how much the current limit, once the FB voltage become less than the quarter of reference voltage (VREF), the short-circuit protection operates to latch the Pch MOS driver transistor. In latch mode, the operation can be resumed by either turning the IC off and on via the CE/MODE pin, or by restoring power supply to the VIN pin. When sharp load transient happens, a voltage drop at the VOUT is propagated to the FB point through CFB, as a result, short circuit protection may operate in the voltage higher than 1/2 VOUT voltage. When the VIN pin voltage becomes 1.4V or lower, the Pch MOS driver transistor output driver transistor is forced OFF to prevent false pulse output caused by unstable operation of the internal circuitry. When the VIN pin voltage becomes 1.8V or higher, switching operation takes place. By releasing the UVLO function, the IC performs the soft start function to initiate output startup operation. The soft start function operates even when the VIN pin voltage falls momentarily below the UVLO operating voltage. The UVLO circuit does not cause a complete shutdown of the IC, but causes pulse output to be suspended; therefore, the internal circuitry remains in operation. In PFM control operation, until coil current reaches to a specified level (IPFM), the IC keeps the Pch MOS driver transistor on. In this case, time that the Pch MOS driver transistor is kept on (TON) can be given by the following formula. TON= L IPFM / (VIN VOUT) IPFM < PFM Duty Limit > In PFM control operation, the PFM duty limit (DTYLIMIT_PFM) is set to 200% (TYP.). Therefore, under the condition that the duty increases (e.g. the condition that the step-down ratio is small), it's possible for Pch MOS driver transistor to be turned IPFM off even when coil current doesn't reach to IPFM.
Ton
PFM Duty Limit PFM
Lx
Lx
FOSC
I Lx
IPFM 0mA
I Lx
IPFM 0mA
IPFM
IPFM
14/33
XC9235/XC9236/XC9237
Series
OPERATIONAL DESCRIPTION (Continued)
CL High Speed Discharge XC9235B(C)(D)(E)(F)(G)/ XC9236B(C)(D)(E)(F)(G)/ XC9237B(C)(D)(E)(F)(G) series can quickly discharge the electric charge at the output capacitor (CL) when a low signal to the CE pin which enables a whole IC circuit put into OFF state, is inputted via the Nch MOS switch transistor located between the LX pin and the VSS pin. When the IC is disabled, electric charge at the output capacitor (CL) is quickly discharged so that it may avoid application malfunction. Discharge time of the output capacitor (CL) is set by the CL auto-discharge resistance (R) and the output capacitor (CL). By setting time constant of a CL auto-discharge resistance value [R] and an output capacitor value (CL) as ( =C x R), discharge time of the output voltage after discharge via the N channel transistor is calculated by the following formulas.
-t/ or t=ln (VOUT(E) / V) V = VOUT(E) x e V : Output voltage after discharge VOUT(E) : Output voltage t: Discharge time, :CxR C= Capacitance of Output capacitor (CL) R= CL auto-discharge resistance
Output Voltage Dischage Characteristics Rdischg = 300 TYP
100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 CL=10uF CL=20uF CL=50uF
Discharge Time t (ms)
15/33
XC9235/XC9236/XC9237 Series
OPERATIONAL DESCRIPTION (Continued)
The operation of the XC9235/XC9236/XC9237 series will enter into the shut down mode when a low level signal is input to the CE/MODE pin. During the shutdown mode, the current consumption of the IC becomes 0 A (TYP.), with a state of high impedance at the Lx pin and VOUT pin. The IC starts its operation by inputting a high level signal to the CE/MODE pin. The input to the CE/MODE pin is a CMOS input and the sink current is 0 A (TYP.).
XC9235/XC9236 series - Examples of how to use CE/MODE pin
(A) SW CE STATUS Stand-by Operation
ON OFF (B) SW CE
STATUS Operation Stand-by (A) (B)
ON OFF
XC9237 series - Examples of how to use CE/MODE pin
(A) SW CE SW PWM/PFM * ON OFF STATUS PWM/PFM Automatic Switching Control PWM Control Stand-by
ON OFF OFF (B) SW CE
SW PWM/PFM * ON OFF
STATUS Stand-by PWM Control PWM/PFM Automatic Switching Control (A) (B)
ON OFF OFF
Intermediate voltage can be generated by RM1 and RM2. Please set the value of each R1, R2, RM1, RM2 from few hundreds k to few hundreds M . For switches, CPU open-drain I/O port and transistor can be used.
16/33
XC9235/XC9236/XC9237
Series
OPERATIONAL DESCRIPTION (Continued)
Soft Start Soft start time is available in two options via product selection. The A,C,D,and E types of XC9235/XC9236/XC9237 series provide 1.0ms (TYP). The B,F, and G types of XC9235/ XC9236/XC9237 series provide 0.25ms (TYP). However, for the D/F the soft-start time can be set by the external components. Soft start time is defined as the time interval to reach 90% of the output voltage from the time when the CE pin is turned on.
90% of setting voltage
FUNCTION CHART
CE/MODE VOLTAGE LEVEL H Level (*1) M Level (*2) L Level (*3) Stand-by Stand-by OPERATIONAL STATES XC9235 Synchronous PWM Fixed Control XC9236 Synchronous PWM/PFM Automatic Switching XC9237 Synchronous PWM/PFM Automatic Switching Synchronous PWM Fixed Control Stand-by
Note on CE/MODE pin voltage level range (*1) H level: 0.65V < H level < VIN V (for XC9235/XC9236) H level: VIN - 0.25V < H level < VIN (for XC9237) (*2) M level: 0.65V < M level < VIN - 1.0V (for XC9237) (*3) L level: 0V < L level < 0.25V
17/33
XC9235/XC9236/XC9237 Series
NOTE ON USE
1. The XC9235/XC9236/XC9237 series is designed for use with ceramic output capacitors. If, however, the potential difference is too large between the input voltage and the output voltage, a ceramic capacitor may fail to absorb the resulting high switching energy and oscillation could occur on the output. If the input-output potential difference is large, connect an electrolytic capacitor in parallel to compensate for insufficient capacitance. 2. Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced by external component selection, such as the coil inductance, capacitance values, and board layout of external components. Once the design has been completed, verification with actual components should be done. 3. Depending on the input-output voltage differential, or load current, some pulses may be skipped, and the ripple voltage may increase. 4. When the difference between VIN and VOUT is large in PWM control, very narrow pulses will be outputted, and there is the possibility that some cycles may be skipped completely. 5. When the difference between VIN and VOUT is small, and the load current is heavy, very wide pulses will be outputted and there is the possibility that some cycles may be skipped completely. 6. With the IC, the peak current of the coil is controlled by the current limit circuit. Since the peak current increases when dropout voltage or load current is high, current limit starts operation, and this can lead to instability. When peak current becomes high, please adjust the coil inductance value and fully check the circuit operation. In addition, please calculate the peak current according to the following formula: Ipk = (VIN - VOUT) x OnDuty / (2 x L x fOSC) + IOUT L: Coil Inductance Value fOSC: Oscillation Frequency 7. When the peak current which exceeds limit current flows within the specified time, the built-in Pch MOS driver transistor turns off. During the time until it detects limit current and before the built-in transistor can be turned off, the current for limit current flows; therefore, care must be taken when selecting the rating for the external components such as a coil. 8. When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. 9. Care must be taken when laying out the PC Board, in order to prevent misoperation of the current limit mode. Depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid the effect of noise, the board should be laid out so that input capacitors are placed as close to the IC as possible. 10. Use of the IC at voltages below the recommended voltage range may lead to instability. 11. This IC should be used within the stated absolute maximum ratings in order to prevent damage to the device. 12. When the IC is used in high temperature, output voltage may increase up to input voltage level at no load because of the leak current of the driver transistor. 13. The current limit is set to 1350mA (MAX.) at typical. However, the current of 1350mA or more may flow. In case that the current limit functions while the VOUT pin is shorted to the GND pin, when Pch MOS driver transistor is ON, the potential difference for input voltage will occur at both ends of a coil. For this, the time rate of coil current becomes large. By contrast, when Nch MOS driver transistor is ON, there is almost no potential difference at both ends of the coil since the VOUT pin is shorted to the GND pin. Consequently, the time rate of coil current becomes quite small. According to the repetition of this operation, and the delay time of the circuit, coil current will be converged on a certain current value, exceeding the amount of current, which is supposed to be limited originally. Even in this case, however, after the over current state continues for several ms, the circuit will be latched. A coil should be used within the stated absolute maximum rating in order to prevent damage to the device. Current flows into Pch MOS driver transistor to reach the current limit (ILIM). The current of ILIM or more flows since the delay time of the circuit occurs during from the detection of the current limit to OFF of Pch MOS driver transistor. Because of no potential difference at both ends of the coil, the time rate of coil current becomes quite small. Lx oscillates very narrow pulses by the current limit for several ms. The circuit is latched, stopping its operation.
Delay LX ILIM ILX Limit >
mS ms
18/33
XC9235/XC9236/XC9237
Series
NOTE ON USE (Continued)
14. In order to stabilize VIN's voltage level and oscillation frequency, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the VIN & VSS pins. 15. High step-down ratio and very light load may lead an intermittent oscillation. 16. During PWM / PFM automatic switching mode, operating may become unstable at transition to continuous mode. Please verify with actual parts.
17. Please note the inductance value of the coil. The IC may enter unstable operation if the combination of ambient temperature, setting voltage, oscillation frequency, and L value are not adequate.
In the operation range close to the maximum duty cycle, The IC may happen to enter unstable output voltage operation even if using the L values listed below.

The Range of L Value
fOSC 3.0MHz 1.2MHz VOUT 0.8VVOUT<4.0V VOUT2.5V 2.5VVOUT L Value 1.0H2.2H 3.3H6.8H 4.7H6.8H
*When a coil less value of 4.7H is used at fOSC=1.2MHz or when a coil less value of 1.5H is used at fOSC=3.0MHz, peak coil current more easily reach the current limit ILMI. In this case, it may happen that the IC can not provide 600mA output current.
18. It may happen to enter unstable operation when the IC operation mode goes into continuous operation mode under the condition of small input-output voltage difference. Care must be taken with the actual design unit.

19/33
XC9235/XC9236/XC9237 Series
NOTE ON USE (Continued)
Instructions of pattern layouts
1. In order to stabilize VIN voltage level, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the VIN & VSS pins. 2. Please mount each external component as close to the IC as possible. 3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit impedance. 4. Make sure that the PCB GND traces are as thick as possible, as variations in ground potential caused by high ground currents at the time of switching may result in instability of the IC. 5. This series' internal driver transistors bring on heat because of the output current and ON resistance of driver transistors.
XC9235/9236/9237A, B, C (Output Voltage Fixed)
XC9235/9236/9237A, B, C, E, G (Output Voltage Fixed)
Inductor Inductor Inductor Inductor
For the VIN, VOUT, VSS/CE, please put the wire. For the VIN, VOUT, VSS/CE, please put the wire.
XC9235/9236/9237D, F (Output Voltage External Setting)
CL
Chip Chip Resistance Resistance Inductor Inductor
For the VIN, VOUT, VSS/CE, please put the wire.
20/33
XC9235/XC9236/XC9237
Series
TEST CIRCUITS
< Circuit No.1 > A/B/C/E/G series
L Wave Form Measure Point
D/F series
L
Wave Form Measure Point IOUT
A
CIN
VIN
Lx
A
CIN CL
VIN
Lx
Cfb R1 CL
CE/MODE VSS
VOUT
V
RL
CE/MODE
VSS
FB
R2
V
RL
External Components External Components L : 1.5uH(NR3015) 3.0MHz 4.7uH(NR4018) 1.2MHz L CIN CL R1 R2 Cfb : 1.5H(NR4018) 3.0MHz : 4.7H (NR3015) 1.2MHz : 4.7F : 10F : 150k : 300k : 120pF VOUT=VFBx(R1+R2)/R2
CIN : 4.7F(ceramic) CL :10F(ceramic)
< Circuit No.2 >
< Circuit No.3 >
Wave Form Measure Point
A
1uF
VIN
Lx VOUT (FB)
VIN
Lx VOUT (FB)
Rpulldown 200
CE/MODE VSS
1uF
CE/MODE VSS
< Circuit No.4 >
VIN Lx
< Circuit No.5 >
VIN
ICEH
Lx VOUT (FB)
A
1uF
CE/MODE VSS
VOUT (FB)
V
100mA
1uF
A
ICEL
CE/MODE VSS
ON resistance = (VIN-VLx)/100mA
< Circuit No.6 >
Wave Form Measure Point
< Circuit No.7 >
Wave Form Measure Point
VIN
Lx VOUT (FB)
VIN
Lx VOUT (FB)
Ilat
1uF
CE/MODE VSS
V
ILIM
1uF
CE/MODE VSS
Rpulldown 1
< Circuit No.8 >
VIN Lx VOUT (FB)
ILx
< Circuit No.9 >
A
A
CIN
VIN
Lx VOUT (FB)
1uF
CE/MODE VSS
CE/MODE VSS
21/33
XC9235/XC9236/XC9237 Series
TYPICAL PERFORMANCE CHARACTERISTICS
(1) Efficiency vs. Output Current
XC9237A18C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F
100 90 80
Efficiency: EFFI (%) Efficency:EFFI(%) Efficiency: EFFI (%) Efficency:EFFI(%)
XC9237A18D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F
100 90 80 PWM/PFM Automatic Sw itching Control
PWM/PFM Automatic Sw itching Control
70 60 50 40 30 20 10 0 0.1
VIN= 4.2V 3.6V 2.4V PWM Control VIN= 4.2V 3.6V 2.4V
70 60 50 40 30 20 10 0 2.4V
VIN= 4.2V 3.6V PWM Control VIN= 4.2V 3.6V 2.4V
1 Output Current: IOUT (mA) 100 10 Output Current:IOUT(mA)
1000
0.1
1 10 Output Current: IOUT (mA) 100 Output Current:IOUT(mA)
1000
(2) Output Voltage vs. Output Current
XC9237A18C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F
2.1 2.0 OutputVoltage: VOUT (V) Output Voltage:Vout(V) 1.9 1.8 1.7 PWM Control 1.6 1.5 0.1 1 10
Output Current: IOUT (mA)
XC9237A18D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F
2.1 2.0
PWM/PFM Automatic Sw itching Control VIN4.2V,3.6V,2.4V
Output Voltage:Vout(V)
1.9 1.8 1.7 1.6 1.5
PWM/PFM Automatic Sw itching Control VIN4.2V,3.6V,2.4V
PWM Control
100
1000
0.1
1
10
Output Current: IOUT (mA)
100
1000
Output Current:IOUT(mA)
Output Current:IOUT(mA)
(3) Ripple Voltage vs. Output Current
XC9237A18C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F XC9237A18D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F
100
100
80
Ripple Voltage: Vr (mV) Ripple Voltage:Vr(mV) Ripple Voltage: Vr (mV) Ripple Voltage:Vr(mV)
80
60 PWM Control VIN4.2V,3.6V,2.4V
40
PWM/PFM Automatic Sw itching Control VIN4.2V 3.6V 2.4V
60
40
PWM/PFM Automatic PWM Control VIN4.2V,3.6V,2.4V Sw itching Control VIN4.2V 3.6V 2.4V
20
20
0 0.1 1 10 100 1000
Output Current: IOUT (mA) Output Current:IOUT(mA)
0 0.1 1 10 100 1000
Output Current: IOUT (mA) Output Current:IOUT(mA)
22/33
XC9235/XC9236/XC9237
Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(4) Oscillation Frequency vs. Ambient Temperature
XC9237A18C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F
1.5
Oscillation Frequency: : FOSC(MHz) Oscillation Frequency FOSC (MHz) Oscillation Frequency : FOSC(MHz) Oscillation Frequency: FOSC (MHz)
XC9237A18D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F
3.5 3.4 3.3 3.2 3.1 3.0 2.9 2.8 2.7 2.6 2.5 -50 -25 0 25 50 75 100 VIN=3.6V
1.4 1.3 1.2 1.1 1.0 0.9 0.8 -50 -25 0 25 50 75 100 VIN=3.6V
Ambient Temperature:Ta ( () Ambient Temperature: Ta )
Ambient Temperature: Ta () ) Ambient Temperature: Ta (
(5) Supply Current vs. Ambient Temperature
XC9237A18C
40 35
Supply Current : IDD (A) Supply Current: IDD ( A)
XC9237A18D
40 35 Supply Current : IDD (A) Supply Current: IDD ( A) VIN=6.0V 30 25 20 15 10 5 0 -50 VIN=2.0V VIN=6.0V VIN=4.0V
30 25 20 15 10 5 0 -50 VIN=2.0V VIN=4.0V
-25
0
25
50
75
100
-25
0
25
50
75
100
Ambient Temperature: Ta ( ) Ambient Temperature: Ta ( )
Ambient Temperature: Ta ( Ambient Temperature: Ta () )
(6) Output Voltage vs. Ambient Temperature
XC9237A18D
2.1 2.0 Output Voltage :VOUT (V) Output Voltage: VOUT (V) 1.9 1.8 1.7 1.6 1.5 -50 -25 0 25 50 75 100 Ambient Temperature: Ta () ) Ambient Temperature: Ta (
UVLO Voltage: UVLO (V) UVLO Voltage : UVLO (V)
(7) UVLO Voltage vs. Ambient Temperature
XC9237A18D
1.8 CE=VIN 1.5 1.2 0.9 0.6 0.3 0.0 -50 -25 0 25 50 75 100 Ambient Temperature: Ta () Ambient Temperature: Ta ( )
VIN=3.6V
23/33
XC9235/XC9236/XC9237 Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(8) CE "H" Voltage vs. Ambient Temperature
XC9237A18D
1.0 CE "H" Voltage : VCEH (V) 0.9
CE "L" Voltage: : VCEL (V) CE "L" Voltage VCEL (V)
(9) CE "L" Voltage vs. Ambient Temperature
XC9237A18D
1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 VIN=2.4V VIN=3.6V VIN=5.0V
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -50 -25 0 25 50 75 100 Ambient Temperature:Ta ( ( ) Ambient Temperature: Ta ) VIN=2.4V VIN=3.6V VIN=5.0V
CE "H" Voltage: VCEH (V)
-50
-25
0
25
50
75
100
Ambient Temperature: Ta ( ()) Ambient Temperature: Ta
(10) Soft Start Time vs. Ambient Temperature
XC9237A18C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F
5 5
XC9237A18D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F
Soft Start Time: TSS (ms) Soft Start Time : TSS (ms)
3
Soft Start Time: : TSS (ms) Soft Start Time TSS (ms)
4
4
3
2
VIN=3.6V
2
VIN=3.6V
1
1
0 -50
-25
0
25
50
75
100
0 -50
-25
0
25
50
75
100
Ambient Temperature: Ta ( Ambient Temperature: Ta () )
Ambient Temperature: ( Ambient Temperature: TaTa ())
(11) "Pch / Nch" Driver on Resistance vs. Input Voltage
XC9237A18D
Lx SW ON Resistance: RLxH, RLxL ( ) () Lx SW ON Resistance:RLxH,RLxL
1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 1 2 3 4 5 6 Input Voltage :VIN (V) Input Voltage: VIN (V) Pch on Resistance Nch on Resistance
24/33
XC9235/XC9236/XC9237
Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(12) XC9235B/36B/37B Rise Wave Form
XC9237B12C L=4.7 H (NR4018), CIN=4.7 F, CL=10 F VIN=5.0V IOUT=1.0mA XC9237B33D L=1.5 H (NR3015), CIN=4.7 F, CL=10 F VIN=5.0V IOUT=1.0mA
VOUT
0.5V/div
VOUT
1.0V/div
CE
0.0V 1.0V
CE
0.0V 1.0V
100 s/div
100 s/div
(13) XC9235B/36B/37B
Soft-Start Time vs. Ambient Temperature
XC9237B12C XC9237B33D F
500
L=4.7 H(NR4018), CIN=4.7 F, CL=10
500
L=1.5 H(NR3015), CIN=4.7 F, CL=10
F
Soft Start Time :TSS (s)
Soft Start Time :TSS (s)
400
400
300
300
200 VIN=5.0V IOUT=1.0mA
200 VIN=5.0V IOUT=1.0mA
100
100
0 -50 -25 0 25 50 75 100
0 -50 -25 0 25 50 75 100
Ambient Temperature: Ta()
Ambient Temperature: Ta()
(14) XC9235B/36B/37B
600
CL Discharge Resistance vs. Ambient Temperature
XC9237B33D
VIN=6.0V
CL Discharge Resistance: ( )
500
VIN=4.0V VIN=2.0V
400
300
200
100 -50
-25
0
25
50
75
100
Ambient Temperature: Ta ()
25/33
XC9235/XC9236/XC9237 Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(15) Load Transient Response XC9237A18C L=4.7 H (NR4018), CIN=4.7 F (ceramic), CL=10 F (ceramic), Topr=25
VIN=3.6V, VCE=VIN (PWM/PFM Automatic Switching Control)
IOUT=1mA
100mA
IOUT=1mA
300mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
50
s/div
50
s/div
IOUT=100mA
1mA
IOUT=300mA
1mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div 200 s/div
2ch VOUT: 50mV/div 200 s/div
26/33
XC9235/XC9236/XC9237
Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(15) Load Transient Response (Continued) XC9237A18C L=4.7 H (NR4018), CIN=4.7 F (ceramic), CL=10 F (ceramic), Topr=25
VIN=3.6V, VCE=1.8V (PWM Control)
IOUT=1mA
100mA
IOUT=1mA
300mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
50
s/div
50
s/div
IOUT=100mA
1mA
IOUT=300mA
1mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
200
s/div
200
s/div
27/33
XC9235/XC9236/XC9237 Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(15) Load Transient Response (Continued) XC9237A18D L=1.5 H (NR3015), CIN=4.7 F (ceramic), CL=10 F (ceramic), Topr=25
VIN=3.6V, VCE=VIN (PWM/PFM Automatic Switching Control)
IOUT=1mA
100mA
IOUT=1mA
300mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
50
s/div
50
s/div
IOUT=100mA
1mA
IOUT=300mA
1mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
200
s/div
200
s/div
28/33
XC9235/XC9236/XC9237
Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(15) Load Transient Response (Continued) XC9237A18D L=1.5 H (NR3015), CIN=4.7 F (ceramic), CL=10 F (ceramic), Topr=25
VIN=3.6V, VCE=1.8V (PWM Control)
IOUT=1mA
100mA
IOUT=1mA
300mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
50
s/div
50
s/div
IOUT=100mA
1mA
IOUT=300mA
1mA
1ch: IOUT
1ch: IOUT
2ch VOUT: 50mV/div
2ch VOUT: 50mV/div
200
s/div
200
s/div
29/33
XC9235/XC9236/XC9237 Series
PACKAGING INFORMATION
SOT-25 USP-6C
USP-6C Reference Pattern Layout
2.4 0.45 0.45
USP-6C Reference Metal Mask Design
1 2 3
0.05 1.0 0.05
6 5 4
30/33
XC9235/XC9236/XC9237
Series
PACKAGING INFORMATION (Continued)
USP-6EL
* A part of the pin may appear from the side of the package because of it's structure, but reliability of the package and strength will not be changed below the standard.
USP-6EL Reference Pattern Layout
USP-6EL Reference Metal Mask Design
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XC9235/XC9236/XC9237 Series
MARKING RULE
SOT-25, USP-6C, USP-6EL
represent product series PRODUCT XC9235 SERIES A B C D E F G SOT-25 (TOP VIEW) 4 C K K 4 2 C
XC9236 5 D L L 5 7 D
XC9237 6 E M M 6 B E
represents integer number of output voltage and oscillation frequency A/B/C/F Series OUTPUT MARK VOLTAGE (V) fOSC=1.2MHz fOSC=3.0MHz 0.X 1.X 2.X 3.X 4.X
E/G/D Series
A B C D E
F H K L M
USP-6C/USP-6EL USP-6C/USP-6EL (Top View) (TOP VIEW)
OUTPUT VOLTAGE (V) 0.X 1.X 2.X 3.X 4.X
MARK fOSC=1.2MlHz N P R S T fOSC=3.0MlHz U V X Y Z
represents decimal point of output voltage VOUT (V) MARK VOUT (V) X.00 X.10 X.20 X.30 X.40 X.50 X.60 X.70 X.80 X.90 0 1 2 3 4 5 6 7 8 9 X.05 X.15 X.25 X.35 X.45 X.55 X.65 X.75 X.85 X.95
MARK A B C D E F H K L M
represents production lot number Order of 01, ...09, 10, 11, ...99, 0A, ...0Z, 1A, ...9Z, A0, ...Z9, AA, ...ZZ. (G, I, J, O, Q, W excluded) *No character inversion used.
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XC9235/XC9236/XC9237
Series
1. The products and product specifications contained herein are subject to change without notice to improve performance characteristics. Consult us, or our representatives before use, to confirm that the information in this datasheet is up to date. 2. We assume no responsibility for any infringement of patents, patent rights, or other rights arising from the use of any information and circuitry in this datasheet. 3. Please ensure suitable shipping controls (including fail-safe designs and aging protection) are in force for equipment employing products listed in this datasheet. 4. The products in this datasheet are not developed, designed, or approved for use with such equipment whose failure of malfunction can be reasonably expected to directly endanger the life of, or cause significant injury to, the user. (e.g. Atomic energy; aerospace; transport; combustion and associated safety equipment thereof.) 5. Please use the products listed in this datasheet within the specified ranges. Should you wish to use the products under conditions exceeding the specifications, please consult us or our representatives. 6. We assume no responsibility for damage or loss due to abnormal use. 7. All rights reserved. No part of this datasheet may be copied or reproduced without the prior permission of TOREX SEMICONDUCTOR LTD.
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