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Impala Linear Corporation
ILC7281
Advance Micropower Dual 150mA CMOS RF LDOTM Regulators with Power Supply Reset Monitor
General Description The ILC7281 provides two independant 150mA low dropout (LDO) voltage regulators and power supply reset monitor in an 8-pin MSOP package. Each regulator output is independantly short circuit protected and has independant shutdown. The device offers a unique combination of low dropout voltage and low quiescent current of CMOS and low noise and high ripple rejection characteristics of bipolar LDO regulators. Moreover, only one input capacitor is required. The power supply reset monitor is available in a 1% accurate trip voltage to fit most microprocessor applications. Even though its output can sink 2mA, the monitor draws only 1A in normal operation. Additionally, a built-in hysteresis of 5% of detect voltage simplifies system design. Dropout Voltage: Typically 150mV at 150mA load, and 1mV at 1mA load. Ground pin current: Typically 20A at 1mA load, and 30A at 150mA load. Ripple rejection: 75dB at 1kHz and 60dB at 100kHz. Shutdown mode: Less than 0.5A quiescent current in shutdown mode. Small package: 8-pin MSOP. Small capacitor: Requires only a 0.47F external cpacitor on the regulator output. Precision output: Output voltage trimmed to 1% accuracy. * * * * * * * * * * * *
Features Guaranteed 150mA output per regulator Ultra low 150mV dropout at 150mA 1% output voltage accuracy Built-in hysteresis of 5% of detection voltage Requires only 0.47F output capacitor Only 30A ground current at 150mA load 75dB ripple rejection at 1kHz (COUT = 0.47F) 80VRMS noise at BW = 300Hz to 50kHz Excellent line and load transient rsponse Over current / over temperature protection 8-pin MSOP package -80dB cross talk Applications * * * * * * Cellular Phones, pagers and wireless headsets Microprocessor reset circuits Palmtops, oragnizers, PDA's and portable electronics Microprocessor reset circuits Battery powered portable appliances Memory battery back-up circuitry
Ordering Information* (TA = -40C to +85C)
ILC7281CS-2530 150mA 2.5V and 3.0V LDO regulators with 2.7V detect fail voltage (VDF) Monitor
Figure 1
VIN
10K VOUTB 0.47-2.2F + CNOISE ceramic 470pF + 1F ceramic ENB ENA GND
VOUT RESET
+
VOUTA
+
0.47-2.2F ceramic
Note: Enable may be connected to VIN, CNOISE connects to both LDO's
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
1
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Pin-Package Configurations Figure 2
VIN VOUTB CNOISE(optional) ENB
1 2 3 4 8 7 6 5
VOUT RESET GND VOUTA ENA
MSOP
(TOP VIEW)
ILC7281CS-XXXX
Pin Functions ILC7281
Pin Number 1 2 3 4 5 6 7 8 Pin Name VIN VOUTB CNOISE(optional) Pin Description Supply Input Regulator Output B Voltage Reference Bypass: Connect external 470pF capacitor to GND to reduce output noise in regulator "A" or "B." May be left open. Enable/Shutdown B (Input): CMOS compatible input. Logic high = enable, logic low or open = shutdown. Do not leave floating. Enable/Shutdown A (Input): CMOS compatible input. Logic high = enable, logic low or open = shutdown. Do not leave floating. Regulator Output A Ground Power supply reset monitor output. N-CH open drain output, must connect through a resistor to supply voltage.
ENB ENA VOUTA GND VOUT RESET
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
2
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Absolute Maximum Ratings for Regulators (Note 1)
Parameter Input Voltage S/D Input Voltage Output Current Output Voltage Power Dissipation Maximum Junction Temp Range Storage Temperature ESD Rating Operating Input Voltage Operating Ambient Temperature Package Thermal Resistance VIN TA JA Symbol VIN VS/D IOUT VOUT Pd TJ(max) Tstg Ratings -0.3 to +12 -0.3 to VIN Short circuit protected -0.3 to 10 Internally Limited -40~+125 -40~+125 2 2.1 to 10 -40 to +85 200 Units V mA V mW C C kV V C C/W
Electrical Characteristics ILC7281CS
Unless otherwise specified, all limits are at TA = 25C; VIN = VO(NOM) + 1V, IOUT = 1mA, COUT = 0.47F, VS/D = 2V. Boldface limits apply over the operating temperature range. (Note 2) Parameter Output Voltage Output Voltage Output Voltage Line Regulation Dropout Voltage (Note 3) Dropout Voltage (Note 3) Dropout Voltage (Note 3) Ground Pin Current Ground Pin Current Ground Pin Current Shutdown Current Symbol VOUT VOUT VOUT VO/VIN VIN - VOUT VIN - VOUT VIN - VOUT IGND IGND IGND IS/D
(408) 574-3939 www.impalalinear.com
Conditions IOUT = 1mA 1mA < IOUT < 100mA 1mA < IOUT < 100mA 1mA < IOUT < 150mA 1mA < IOUT < 150mA VO(NOM) + 1V < VIN < 10V IOUT = 0mA IOUT = 10mA IOUT =150mA IOUT = 0mA IOUT = 10mA IOUT = 150mA
Min -1 -1.5 -2.5 -2.5 -3.5
Typ VOUT (Nom.) VOUT (Nom.) VOUT (Nom.) 0.007 0.1 10 150 20 25 30 0.1
Max +1 +1.5 +2.5 2.5 +3.5 0.014 0.032 1 2 15 20 175 200 60 80 70 90 80 120 1
Units %V (Nom.) %V (Nom.) %V (Nom.) %/V mV mV mV A A A A
Impala Linear Corporation
ILC7281 1.0
Nov 2000
3
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Electrical Characteristics ILC7281CS
Unless otherwise specified, all limits are at TA = 25C; VIN = VO(NOM) + 1V, IOUT = 1mA, COUT = 0.47F, VS/D = 2V. Boldface limits apply over the operating temperature range. (Note 2) Parameter Shutdown Input Voltage Peak Output Current (Note 4) Output Noise Voltage (RMS) Ripple Rejection Symbol VS/D IO(peak) eN VO/VIN VO(line) VO(load) ISC Conditions High = Regulator On Low = Regulator Off VOUT > 0.95VO(NOM) BW = 300Hz to 50kHz, CNOISE = 0pF freq = 1kHz freq = 10kHz freq = 100kHz VIN: VO(NOM) + 1V to VO(NOM) + 2V; dVIN/dt = 1V/S;lo = 150mA IOUT: 0 to 150mA; d(lOUT)/dt = 50A/s, with COUT = 2.2F VOUT = 0V Min 2.0 300 500 80 75 70 60 10 40 20 300 -60 mV dB Typ Max 10 0.6 mA VRMS Units V
Dynamic Line Regulation
Dynamic Load Regulation Short Circuit Current Cross Talk
mV mA dB
Note1: Absolute maximum ratings indicate limits which when exceeded may result in damage to the component. Electrical specifications do not apply when operating the device outside of its rated operating conditions. Note 2: Specified Min/Max limits are production tested or guaranteed through correlation based on statistical control methods. Measurements are taken at constant junction temperature as close to ambient as possible using low duty pulse testing. Note 3: Dropout voltage is defined as the input to output differential voltage at which the output voltage drops 2% below the nominal value measured with a 1V differential. Note 4: Guaranteed by design
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
4
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Absolute Maximum Ratings Supply Reset Monitor (TA = 25C)
Parameter Input Voltage Output Current Output Voltage Continuous Total Power Dissipation (SOT-23) Operating Ambient Temperature Storage Temperature Symbol VIN IOUT VOUT Pd Topr Tstg Ratings 12 50 VSS-0.3~VIN+0.3 150 -30~+80 -40~+125 Units V mA V mW C C
Electrical Characteristics Power Supply Reset Monitor (TA = 25C)
Paramter Detect Fail Voltage Hysteresis Range Symbol VDF VHYS VIN VIN VIN VIN VIN = = = = = 1.5V 2.0V 3.0V 4.0V 5.0V Conditions A grade Min VDF X 0.99 Typ VDF 0.9 1.0 1.3 1.6 2.0 Max VDF X 1.01 2.6 3.0 3.4 3.8 4.2 10.0 Units V V
VDF X 0.02 VDF X 0.05 VDF X 0.08
Supply Current
ISS
1.5
A
Operating Voltage
VIN
VDF = 2.1~6.0V N-ch VDS = 0.5V VIN = 1.0V VIN = 2.0V VIN = 3.0V VIN = 4.0V VIN = 5.0V 2.2 7.7 10.1 11.5 13.0 100
V
Output Current
IOUT
mA
Temperature Characteristics Delay Time (Release Voltage Output Inversion)
VDF/(Topr*VDF) -30C < Topr < 80C tDLY (VDR VOUT Inversion)
ppm/C 0.2 ms
Note:
1. An additional resistor between the VIN pin and supply voltage may cause deterioration of the characteristics due to increasing of VDR.
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
5
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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VINA
VOUTA
+ VIN
BANDGAP REF.
ENA
CURRENT LIMIT THERMAL SHUTDOWN
VOUT
VINB
VREF GND
VOUTB CNOISE
BANDGAP REF.
N - Channel Open Drain Output
+ ENB
CURRENT LIMIT THERMAL SHUTDOWN
GND
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
6
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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APPLICATIONS INFORMATION - Regulators Enable/Shutdown Forcing ENA/B (enable/shutdown) high (>2V) enables the regulator. ENA/B is compatible with CMOS logic gates. If the enable/shutdown feature is not required, connect ENA/B to VINA/B (supply input). Input Capacitor A 1F capacitor should be placed from VINA/B to GND if there is more than 10 inches of wire between the input and the ac filter capacitor or if a battery is used as the input. Reference Bypass Capacitor CNOISE (reference bypass) is connected to the internal voltage reference of regulator A and B. A 470pF capacitor connected from CNOISE to GND decouples the reference, providing a significant reduction in output noise. C NOISE reduces the regulator phase margin; when using C NOISE, output capacitors of 2.2F or greater are generally required to maintain stability. The start-up speed of the ILC7281 is inversely proportional to the size of the reference bypass capacitor. Applications requiring a slow ramp-up of output voltage should consider larger values of CNOISE. Likewise, if rapid turn-on is necessary, consider omitting CNOISE. If output noise is not a major concern, omit CNOISE and leave the pin open. Output Capacitor An output capacitor is required between VOUTA/B and GND to prevent oscillation. The minimum size of the output capacitor is dependent upon whether a reference bypass capacitor is used. 1.0F minimum is recommended when CNOISE is not used (see figure 2). 2.2F minimum is recommended when CNOISE is 470pF (see figure 1). Larger values slow the regulator's transient response. The output capacitor value may be increased without limit. The output capacitor should have an ESR (effective series resistance) of about 5 or less and a resonant frequency above 1MHz. Ultra low ESR capacitors may be used and will not cause a low-amplitude oscillation and/or underdamped transient response which shows up in some LDO regulators. Most ceramic capacitors are adequate so there is no need for more expensive tantalum capacitors. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.47F for current below 10mA or 0.33F for currents below 1mA No-Load Stability The ILC7281 will remain stable and in regulation with no load unlike many other voltage regulators. This is expecially important in CMOS RAM KeepAlive applications.
Impala Linear Corporation
ILC7281 1.0
Dual-Supply Operation When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground. Thermal Considerations Multilayer boards having a ground plane, wide traces near the pads, and large supply bus lines provide better thermal conductivity. The 8-lead MSOP has a thermal resistance of 200C/W when mounted on an FR4 board with minimum trace widths and no ground plane. Thermal Evaluation Examples For example, at 50C ambient temperature, the maximum package power dissipation is: P D(max) = (125C - 50C)/200C/W P D(max) = 375mW If the intent is to operate the part from a 4V supply at the full 150mA load for both outputs in a 50C maximum ambient temperature, make the following calculations: P P P P P D(each regulator) = (VIN - VOUT) IOUT + (VIN IGND) D(each regulator) = (4V - 3V) 150mA + (4V 0.12mA) D(each regulator) = 150mW D(both regulators) = 2 regulators 150mW D(both regulators) = 300mW
The actual total power dissipation of 300mW is below the 375mW package maximum; therefore the regulator can be used. Note that both regulators cannot always be used at their maximum current rating. For example, in a 5V input to 3.0V output application at 50C, if one regulator supplies 150mA, the other regulator is limited to a much lower current. The first regulator dissipates: P D = (5V - 3.0V) 150 + 0.12mA (5V) P D = 267.5mW Then, the load that the remaining regulator can dissipate must not exceed: 375mW - 267.5mW = 107.5mW. This means, using the same 5V input and 3.3V output voltage, the second regulator is limited to about 60mA Taking advantage of the extremely low dropout voltage characteristics of the ILC7281, power dissipation can be reduced by using the lowest possible input voltage to minimize the input to output voltage drop.
(408) 574-3939
www.impalalinear.com
Nov 2000
7
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Functional Descriptin - Power Supply Reset Monitor
The following designators 1~6 refer to the timing diagram below. 1. While the input voltage (VIN) is higher than the detect fail voltage (VDF); the VOUT output pin is at high impedence state. 2. When the input VIN voltage falls lower than VDF, VOUT drops near to ground voltage. 3. If the input voltage decreases below the minimum operating voltage (VMIN), the VOUT output becomes unstable. In this condition, if the VOUT pin is pulled up, VOUT indicates the VIN voltage. 4. During an increase of the input voltage from VSS voltage, VOUT is not stable in the voltage below the VMIN. Exceeding that level, the output stays at the ground level (VSS) between the minimum operating voltage (VMIN) and detect release voltage (VDR). 5. If the input voltage increases more than VDR, the VOUT output pin is at high impedence state. 6. The difference between VDR and VDF is the hysteresis in the system.
Timing Diagram
INPUT VOLTAGE (VIN) DETECT RELEASE VOLTAGE (VDR)
6
DETECT FAIL VOLTAGE (VDF)
MINIMUM OPERATING VOLTAGE (VMIN) GROUND VOLTAGE (VSS) OUTPUT VOLTAGE (VOUT)
GROUND VOLTAGE (VSS)
1 2 3 4 5
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
8
Micropower Dual 150mA CMOS RF-LDOTM Regulators with Power Supply Reset Monitor
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Package Dimensions
MSOP-8
0.116 12 TYP 0.118 0.004 0.020 TYP 12 TYP 0.118 0.037 0.0215 0.118 0.004 3 TYP 0.006 RAD. TYP
0.000-0.005 RAD. TYP
0.040 0.013 TYP 0.0256 BSC 0.004 SEATING PLANE
Devices sold by Impala Linear Corporation are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Impala Linear Corporation makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Impala Linear Corporation makes no warranty of merchantability or fitness for any purpose. Impala Linear Corporation reserves the right to discontinue production and change specifications and prices at any time and without notice. This product is intended for use in normal commercial applications. Applications requiring an extended temperature range, unusual environmental requirements, or high reliability applications, such as military and aerospace, are specifically not recommended without additional processing by Impala Linear Corporation. Impala Linear Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in an Impala Linear Corporation product. No other circuits, patents, licenses are implied.
Life Support Policy Impala Linear Corporation's products are not authorized for use as critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labelling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonbly expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
Impala Linear Corporation
ILC7281 1.0
(408) 574-3939
www.impalalinear.com
Nov 2000
9

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