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LTC3400/LTC3400B 600mA, 1.2MHz Micropower Synchronous Boost Converter in ThinSOT
FEATURES
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DESCRIPTIO
Up to 92% Efficiency Generates 3.3V at 100mA from a Single AA Cell Low Start-Up Voltage: 0.85V 1.2MHz Fixed Frequency Switching Internal Synchronous Rectifier 2.5V to 5V Output Range Automatic Burst Mode(R) Operation (LTC3400) Continuous Switching at Light Loads (LTC3400B) Logic Controlled Shutdown (< 1A) Antiringing Control Minimizes EMI Tiny External Components Low Profile (1mm) ThinSOTTM Package
The LTC(R)3400/LTC3400B are synchronous, fixed frequency, step-up DC/DC converters delivering high efficiency in a 6-lead ThinSOT package. Capable of supplying 3.3V at 100mA from a single AA cell input, the devices contain an internal NMOS switch and PMOS synchronous rectifier. A switching frequency of 1.2MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3400 features automatic shifting to power saving Burst Mode operation at light loads, while the LTC3400B features continuous switching at light loads. Antiringing control circuitry reduces EMI concerns by damping the inductor in discontinuous mode, and the devices feature low shutdown current of under 1A. Both devices are available in the low profile (1mm) ThinSOT package.
, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation.
APPLICATIO S
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Pagers MP3 Players Digital Cameras LCD Bias Supplies Handheld Instruments Wireless Handsets GPS Receivers
TYPICAL APPLICATIO
L1 4.7H
100
+
SINGLE AA CELL
C1 4.7F
1 6 SW VIN VOUT 5 R1 1.02M 1% R2 604k 1% VOUT 3.3V 100mA C2 4.7F
90 EFFICIENCY (%) 80 70 60 50 FIGURE 1 CIRCUIT WITH OPTIONAL SCHOTTKY DIODE (SEE APPLICATIONS INFORMATION) 1 10 100 LOAD CURRENT (mA) 1000
3400 F01a
LTC3400 OFF ON 4 SHDN GND 2 C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML L1: COILCRAFT DO160C-472 FB 3
3400 F01
40 0.1
Figure 1. Single Cell to 3.3V Synchronous Boost Converter
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Efficiency
VIN = 2.4V VIN = 1.5V
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1
LTC3400/LTC3400B
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW SW 1 GND 2 FB 3 6 VIN 5 VOUT 4 SHDN
VIN Voltage ................................................. - 0.3V to 6V SW Voltage ................................................. - 0.3V to 6V SHDN, FB Voltage ....................................... - 0.3V to 6V VOUT ........................................................... - 0.3V to 6V Operating Temperature Range (Note 2) .. - 30C to 85C Storage Temperature Range ................... - 65C to 125 Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER LTC3400ES6 LTC3400BES6 S6 PART MARKING LTWK LTUN
S6 PACKAGE 6-LEAD PLASTIC SOT-23
TJMAX = 125C, JA = 256C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER Minimum Start-Up Voltage Minimum Operating Voltage Output Voltage Adjust Range Feedback Voltage Feedback Input Current Quiescent Current (Burst Mode Operation) Quiescent Current (Shutdown) Quiescent Current (Active) NMOS Switch Leakage PMOS Switch Leakage NMOS Switch On Resistance PMOS Switch On Resistance NMOS Current Limit Burst Mode Operation Current Threshold Current Limit Delay to Output Max Duty Cycle Switching Frequency
The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = 1.2V, VOUT = 3.3V, unless otherwise specified.
CONDITIONS ILOAD = 1mA SHDN = VIN (Note 4) 2.5
q
MIN
TYP 0.85 0.5
MAX 1 0.65 5 1.268 30 1 500 5 5
UNITS V V V V nA A A A A A mA mA ns %
1.192
1.23 1 19 0.01 300 0.1 0.1 0.35 0.20 0.45 0.30
VFB = 1.25V (Note 3) VFB = 1.4V (Note 5), LTC3400 Only VSHDN = 0V, Not Including Switch Leakage Measured On VOUT VSW = 5V VSW = 0V VOUT = 3.3V VOUT = 5V VOUT = 3.3V VOUT = 5V 600 LTC3400 Only (Note 3) (Note 3) VFB = 1.15V
q q
850 3 40
80 0.95 0.85 1
87 1.2 1.2 1.5 1.5 0.35
SHDN Input High SHDN Input Low SHDN Input Current VSHDN = 5.5V
0.01
1
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3400E/LTC3400BE are guaranteed to meet performance specifications from 0C to 70C. Specifications over the - 30C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: Specification is guaranteed by design and not 100% tested in production. Note 4: Minimum VIN operation after start-up is only limited by the battery's ability to provide the necessary power as it enters a deeply discharged state. Note 5: Burst Mode operation IQ is measured at VOUT. Multiply this value by VOUT/VIN to get the equivalent input (battery) current.
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2
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MHz MHz V V A
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WW
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LTC3400/LTC3400B TYPICAL PERFOR A CE CHARACTERISTICS
Output Load Burst Mode Threshold vs VIN
L = 4.7H TA = 25C OUTPUT CURRENT (mA) 20 VOUT = 3.3V VOUT = 5V
3.32 VOUT (V) 3.30 3.28 3.26 3.36 3.34
START-UP VOLTAGE (V)
10
0 0.9 1.5 2.1 2.7 VIN (V) 3.3 3.9 4.5
3400 G01
No Load Battery Current vs VBATT
1000 VOUT = 3.3V TA = 25C
NORMALIZED FREQUENCY
BATTERY CURRENT (A)
100
10 0.9
1.2
1.5 1.8 2.1 2.4 BATTERY VOLTAGE (V)
SW Pin Fixed Frequency, Continuous Inductor Current Operation
VSW 1V/DIV
0V VIN = 1.3V VOUT = 3.3V IOUT = 50mA L = 6.8H COUT = 4.7F 100ns/DIV
3400 G07
UW
2.7
3400 G04
VOUT vs Temperature
FIGURE 1 CIRCUIT IO = 10mA 1.4 1.3 1.2 1.1 1.0 0.9 0.8 -30 0 30 60 TEMPERATURE (C) 90 120
3400 G02
Minimum Start-Up Voltage vs Load Current
TA = 25C
3.24 -60
0.1
1 10 IOUT (mA) CURRENT SOURCE LOAD
100
3400 G03
Normalized Oscillator Frequency vs Temperature
1.01 1.00 0.99 0.98 0.97 0.96 0.95 -50 -30
SW Pin Antiringing Operation
VSW 1V/DIV
0V VIN = 1.3V VOUT = 3.3V IOUT = 10mA L = 6.8H COUT = 4.7F 100ns/DIV
3400 G06
3.0
30 50 -10 10 TEMPERATURE (C)
70
90
3400 G05
Fixed Frequency and Burst Mode Operation
VOUT Transient Response
VOUT(AC) 100mV/DIV 60mA 10A VIN = 1.3V 10ms/DIV VOUT = 3.3V IOUT = 60mA TO 10A L = 6.8H COUT = 4.7F
3400 G08
VOUT(AC) 100mV/DIV 100mA IOUT 40mA VIN = 1.3V 100s/DIV VOUT = 3.3V IOUT = 40mA TO 100mA L = 6.8H COUT = 4.7F
3400 G09
IOUT
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LTC3400/LTC3400B
PI FU CTIO S
SW (Pin 1): Switch Pin. Connect inductor between SW and VIN. Optional Schottky diode is connected between SW and VOUT. Keep these PCB trace lengths as short and wide as possible to reduce EMI and voltage overshoot. If the inductor current falls to zero, or SHDN is low, an internal 100 antiringing switch is connected from SW to VIN to minimize EMI. GND (Pin 2): Signal and Power Ground. Provide a short direct PCB path between GND and the (-) side of the output capacitor(s). FB (Pin 3): Feedback Input to the gm Error Amplifier. Connect resistor divider tap to this pin. The output voltage can be adjusted from 2.5V to 5V by: VOUT = 1.23V * [1 + (R1/R2)] SHDN (Pin 4): Logic Controlled Shutdown Input. SHDN = High: Normal free running operation, 1.2MHz typical operating frequency. SHDN = Low: Shutdown, quiescent current < 1A. 100 connected between SW and VIN. Typically, SHDN should be connected to VIN through a 1M pull-up resistor. VOUT (Pin 5): Output Voltage Sense Input and Drain of the Internal Synchronous Rectifier MOSFET. Bias is derived from VOUT. PCB trace length from VOUT to the output filter capacitor(s) should be as short and wide as possible. VOUT is held at VIN - 0.6V in shutdown due to the body diode of the internal PMOS. VIN (Pin 6): Battery Input Voltage. The device gets its start-up bias from VIN. Once VOUT exceeds VIN, bias comes from VOUT. Thus, once started, operation is completely independent from VIN. Operation is only limited by the output power level and the battery's internal series resistance.
BLOCK DIAGRA
+
SINGLE CELL INPUT 6 VIN
VOUT GOOD START-UP OSC A B A/B MUX
PWM CONTROL RAMP GEN 1.2MHz PWM COMPARATOR
SYNC DRIVE CONTROL
SLOPE COMP
SLEEP
Burst Mode OPERATION CONTROL
CC 150pF
CP2 2.5pF
SHDN 4 SHUTDOWN CONTROL SHUTDOWN
2 GND
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4
+
RC 80k
gm ERROR AMP
-
-
+
- - +
W
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L1 4.7H CIN 1F 1 SW
OPTIONAL SCHOTTKY
2.3V 0.45 VOUT 5 3.3V OUTPUT
0.35 R1 1.02M 1% (EXTERNAL)
CURRENT SENSE
FB 3 1.23V REF COUT 4.7F
R2 604k 1% (EXTERNAL)
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LTC3400/LTC3400B
OPERATIO
The LTC3400/LTC3400B are 1.2MHz, synchronous boost converters housed in a 6-lead ThinSOT package. Able to operate from an input voltage below 1V, the devices feature fixed frequency, current mode PWM control for exceptional line and load regulation. With its low RDS(ON) and gate charge internal MOSFET switches, the devices maintain high efficiency over a wide range of load current. Detailed descriptions of the three distinct operating modes follow. Operation can be best understood by referring to the Block Diagram. Low Voltage Start-Up The LTC3400/LTC3400B will start up at a typical VIN voltage of 0.85V or higher. The low voltage start-up circuitry controls the internal NMOS switch up to a maximum peak inductor current of 850mA (typ), with an approximate 1.5s off-time during start-up, allowing the devices to start up into an output load. Once VOUT exceeds 2.3V, the start-up circuitry is disabled and normal fixed frequency PWM operation is initiated. In this mode, the LTC3400/ LTC3400B operate independent of VIN, allowing extended operating time as the battery can droop to several tenths of a volt without affecting output voltage regulation. The limiting factor for the application becomes the ability of the battery to supply sufficient energy to the output. Low Noise Fixed Frequency Operation Oscillator: The frequency of operation is internally set to 1.2MHz. Error Amp: The error amplifier is an internally compensated transconductance type (current output) with a transconductance (gm) = 33 microsiemens. The internal 1.23V reference voltage is compared to the voltage at the FB pin to generate an error signal at the output of the error amplifier. A voltage divider from VOUT to ground programs the output voltage via FB from 2.5V to 5V using the equation: VOUT = 1.23V * [1 + (R1/R2)] Current Sensing: A signal representing NMOS switch current is summed with the slope compensator. The summed signal is compared to the error amplifier output to provide a peak current control command for the PWM. Peak switch current is limited to approximately 850mA
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independent of input or output voltage. The current signal is blanked for 40ns to enhance noise rejection. Zero Current Comparator: The zero current comparator monitors the inductor current to the output and shuts off the synchronous rectifier once this current reduces to approximately 20mA. This prevents the inductor current from reversing in polarity improving efficiency at light loads. Antiringing Control: The antiringing control circuitry prevents high frequency ringing of the SW pin as the inductor current goes to zero by damping the resonant circuit formed by L and CSW (capacitance on SW pin). Burst Mode Operation Portable devices frequently spend extended time in low power or standby mode, only switching to high power drain when specific functions are enabled. In order to improve battery life in these types of products, high power converter efficiency needs to be maintained over a wide output power range. In addition to its high efficiency at moderate and heavy loads, the LTC3400 includes automatic Burst Mode operation that improves efficiency of the power converter at light loads. Burst mode operation is initiated if the output load current falls below an internally programmed threshold (see Typical Performance graph, Output Load Burst Mode Threshold vs V IN). Once initiated, the Burst Mode operation circuitry shuts down most of the device, only keeping alive the circuitry required to monitor the output voltage. This is referred to as the sleep state. In sleep, the LTC3400 draws only 19A from the output capacitor, greatly enhancing efficiency. When the output voltage has drooped approximately 1% from nominal, the LTC3400 wakes up and commences normal PWM operation. The output capacitor recharges and causes the LTC3400 to reenter sleep if the output load remains less than the sleep threshold. The frequency of this intermittent PWM or burst operation is proportional to load current; that is, as the load current drops further below the burst threshold, the LTC3400 turns on less frequently. When the load current increases above the burst threshold, the LTC3400 will resume continuous PWM operation seamlessly. The LTC3400B does not use Burst Mode operation and features continous operation at light loads, eliminating low frequency output voltage ripple at the expense of light load efficiency.
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LTC3400/LTC3400B
APPLICATIO S I FOR ATIO
PCB LAYOUT GUIDELINES
The high speed operation of the LTC3400/LTC3400B demands careful attention to board layout. You will not get advertised performance with careless layout. Figure 2 shows the recommended component placement. A large ground pin copper area will help to lower the chip temperature. A multilayer board with a separate ground plane is ideal, but not absolutely necessary.
(OPTIONAL)
OUTPUT CURRENT (mA)
VIN
1 2 3
SW
VIN 6
GND VOUT 5 FB SHDN 4 SHDN
VOUT
3400 F02
RECOMMENDED COMPONENT PLACEMENT. TRACES CARRYING HIGH CURRENT ARE DIRECT. TRACE AREA AT FB PIN IS SMALL. LEAD LENGTH TO BATTERY IS SHORT
Figure 2. Recommended Component Placement for Single Layer Board
COMPONENT SELECTION Inductor Selection The LTC3400/LTC3400B can utilize small surface mount and chip inductors due to their fast 1.2MHz switching frequency. A minimum inductance value of 3.3H is necessary for 3.6V and lower voltage applications and 4.7H for output voltages greater than 3.6V. Larger values of inductance will allow greater output current capability by reducing the inductor ripple current. Increasing the inductance above 10H will increase size while providing little improvement in output current capability. The approximate output current capability of the LTC3400/ LTC3400B versus inductance value is given in the equation below and illustrated graphically in Figure 3.
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180 160 140 120 VOUT = 5V 110 80 60 3 5 7 9 11 13 15 17 19 21 23 INDUCTANCE (H)
3400 F03
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VIN =1.2V
VOUT = 3V VOUT = 3.3V VOUT = 3.6V
Figure 3. Maximum Output Current vs Inductance Based On 90% Efficiency
V *D IOUT(MAX) = * IP - IN * (1 - D) f * L * 2 where: = estimated efficiency IP = peak current limit value (0.6A) VIN = input (battery) voltage D = steady-state duty ratio = (VOUT - VIN)/VOUT f = switching frequency (1.2MHz typical) L = inductance value The inductor current ripple is typically set for 20% to 40% of the maximum inductor current (IP). High frequency ferrite core inductor materials reduce frequency dependent power losses compared to cheaper powdered iron types, improving efficiency. The inductor should have low ESR (series resistance of the windings) to reduce the I2R power losses, and must be able to handle the peak inductor current without saturating. Molded chokes and some chip inductors usually do not have enough core to support the peak inductor currents of 850mA seen on the LTC3400/LTC3400B. To minimize radiated noise, use a toroid, pot core or shielded bobbin inductor. See Table 1 for some suggested components and suppliers.
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LTC3400/LTC3400B
APPLICATIO S I FOR ATIO
Table 1. Recommended Inductors
L (H) 4.1 10 4.7 4.7 10 4.7 3.3 4.7 10 4.7 4.7 10 4.7 MAX DCR m 57 124 105 170 109 182 216 174 60 75 90 84 137 195 HEIGHT (mm) 2.0 2.0 1.8 1.8 3.5 3.5 0.8 0.8 2.9 2.9 2.9 2.0 2.0 2.2
PART CDRH5D18-4R1 CDRH5D18-100 CDRH3D16-4R7 CDRH3D16-6R8 CR43-4R7 CR43-100 CMD4D06-4R7MC CMD4D06-3R3MC DS1608-472 DS1608-103 DO1608C-472 D52LC-4R7M D52LC-100M LQH3C4R7M24
VENDOR Sumida (847) 956-0666 www.sumida.com
Coilcraft (847) 639-6400 www.coilcraft.com Toko (408) 432-8282 www.tokoam.com Murata www.murata.com
Output and Input Capacitor Selection Low ESR (equivalent series resistance) capacitors should be used to minimize the output voltage ripple. Multilayer ceramic capacitors are an excellent choice as they have extremely low ESR and are available in small footprints. A 2.2F to 10F output capacitor is sufficient for most applications. Larger values up to 22F may be used to obtain extremely low output voltage ripple and improve transient response. An additional phase lead capacitor may be required with output capacitors larger than 10F Output Diode Use a Schottky diode such as an MBR0520L, CMDSH2-3, 1N5817 or equivalent if the converter output voltage is 4.5V or greater. The Schottky diode carries the output current for the time it takes for the synchronous rectifier to turn on. Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency. A Schottky diode is optional for output voltages below 4.5V, but will increase converter efficiency by 2% to 3%.
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to maintain acceptable phase margin. X5R and X7R dielectric materials are preferred for their ability to maintain capacitance over wide voltage and temperature ranges. Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. It follows that ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. A 4.7F input capacitor is sufficient for virtually any application. Larger values may be used without limitations. Table 2 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers directly for detailed information on their entire selection of ceramic parts.
Table 2. Capacitor Vendor Information
SUPPLIER AVX Murata Taiyo Yuden PHONE (803) 448-9411 (714) 852-2001 (408) 573-4150 WEBSITE www.avxcorp.com www.murata.com www.t-yuden.com
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LTC3400/LTC3400B
TYPICAL APPLICATIO S
Single Cell to 3.3V Synchronous Boost Converter with Load Disconnect in Shutdown
L1 4.7H D1 1 6 SW VIN VOUT 5 M1 Si2305DS R3 510k 3 C2 4.7F
+
SINGLE AA CELL
OFF ON
D1: CENTRAL SEMI CMDSH2-3 L1: COILCRAFT DS1608-472
8
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C1 4.7F
LTC3400 4 SHDN GND 2 FB
VOUT 3.3V R1 100mA 1.02M 1% R2 604k 1%
R3 510k
Q1 2N3904
3400 TA01a
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LTC3400/LTC3400B
TYPICAL APPLICATIO S
Single Lithium Cell to 5V, 250mA
L1 4.7H
+
EFFICIENCY (%)
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D1 1
LITHIUM CELL
C1 4.7F
6
SW VIN VOUT
5 C2 4.7F R1 1.82M 1% R2 604k 1%
3400 TA02a
LTC3400 OFF ON 4 SHDN GND D1: CENTRAL SEMI CMDSH2-3 L1: SUMIDA CMD4D06-4R7 2 FB 3
3.6V to 5V Efficiency
100 LTC3400 CO = 4.7F L = 4.7H
90
80
70
60
50 0.1
1
10 100 LOAD CURRENT (mA)
1000
3400 TA02b
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LTC3400/LTC3400B
TYPICAL APPLICATIO S
Single Cell AA Cell to 3V Synchronous Boost Converter
L1 4.7H C3 1F 1 6 SW VIN VOUT 5 R1 1.02M 1% R2 750k 1% D1 D2 VOUT1 3V C2 90mA 4.7F
+
SINGLE AA CELL
D1, D2: ZETEX FMND7000 DUAL DIODE L1: COILCRAFT DS1608-472
10
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C1 4.7F
LTC3400 OFF ON 4 SHDN GND 2 FB 3
C4 10F
3400 TA03a
VOUT2 -3V 10mA
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LTC3400/LTC3400B
PACKAGE DESCRIPTIO U
S6 Package 6-Lead Plastic SOT-23
(Reference LTC DWG # 05-08-1636)
2.90 BSC (NOTE 4) 0.754 0.854 0.127 2.80 BSC 1.50 - 1.75 (NOTE 4) PIN ONE ID 0.95 BSC 0.95 BSC 0.30 - 0.45 TYP 6 PLCS (NOTE 3) 0.80 - 0.90 0.20 BSC 1.00 MAX DATUM `A' 0.01 - 0.10 0.09 - 0.20 (NOTE 3) 1.90 BSC
S6 TSOT-23 0801
3.254
1.9 BSC RECOMMENDED SOLDER PAD LAYOUT
0.30 - 0.50 REF NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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LTC3400/LTC3400B
TYPICAL APPLICATIO U
Single AA Cell to 2.5V Synchronous Boost Converter
L1 3.3H D1 1 6 SW VIN VOUT 5 R1 1.02M 1% R2 1.02M 1% VOUT 2.5V 130mA C2 4.7F SINGLE AA CELL C1 4.7F LTC3400 OFF ON D1: CENTRAL SEMI CMDSH2-3 L1: SUMIDA CMD4D06-3R3MC 4 SHDN GND 2 FB 3
3400 TA04a
+
RELATED PARTS
PART NUMBER LT1308A/LT1308B LT1613 LT1615 LT 1618 LT1619 LTC1872 LT1930/LT1930A LT1932 LT1946/LT1946A LT1949 LTC3401 LTC3402 LTC3423 LTC3424
(R)
DESCRIPTION High Current, Micropower, Single Cell 600kHz DC/DC Converter 1.4MHz, Single Cell DC/DC Converter in ThinSOT Micropower Step-Up DC/DC Converter in ThinSOT 1.4MHz Step-Up DC/DC Converter with Current Limit High Efficiency Boost DC/DC Controller ThinSOT Boost DC/DC Controller 1.2MHz/2.2MHz DC/DC Converters in ThinSOT Constant Current Step-Up LED Driver 1.2MHz/2.7MHz Boost DC/DC Converters 600kHz, 1A Switch PWM DC/DC Converter 1A, 3MHz Micropower Synchronous Boost Converter 2A, 3MHz Micropower Synchronous Boost Converter 1A, 3MHz Micropower Synchronous Boost Converter 2A, 3MHz Micropower Synchronous Boost Converter
COMMENTS 5V at 1A with Single Li-Ion Cell, VOUT to 34V VIN as Low as 1.1V, 3V at 30mA from Single Cell IQ = 20A, 1A Shutdown Current, VIN as Low as 1V 1.5A Switch, 1.6V to 18V Input Range, Input or Output Current Limiting 1A Gate Drive, 1.1V to 20V Input, Separate VCC for Gate Drive 50kHz, 2.5V to 9.8V Input VIN = 2.6V to 16V, 5V at 450mA from 3.3V Input Drives Up to Eight White LEDs, ThinSOT Package 1.5A, 36V Internal Switch, 8-Pin MSOP Package 1A, 0.5, 30V Internal Switch, VIN as Low as 1.5V, Low-Battery Detect Active in Shutdown 1A Switch, Programmable Frequency, 10-Pin MSOP Package 2A Switch, Programmable Frequency, 10-Pin MSOP Package 1A Switch, Separate Bias Pin for Low Output Voltages 2A Switch, Separate Bias Pin for Low Output Voltages
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 q FAX: (408) 434-0507
q
LT/TP 0302 2K * PRINTED IN USA
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2001

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