LTC1174 LTC1174-3.3/LTC1174-5 High Efficiency Step-Down and Inverting DC/DC Converter FEATURES DESCRIPTIO High Efficiency: Up to 94% The LTC 1174 is a simple current mode DC/DC converter Peak Inductor Current Independent of ideally suited for 9V to 5V, 5V to 3.3V or 5V to 5V Inductor Value operation. With an internal 0.9 switch (at a supply Short-Circuit Protection voltage of 9V), the LTC1174 requires only four external Optimized for 5V to 5V Applications components to construct a complete high efficiency Wide V Range: 4V to 18.5V DC/DC converter. IN Low Dropout Operation Under a no load condition the LTC1174 draws only 130A. Low-Battery Detector In shutdown, it draws a mere 1A making this converter Pin Selectable Current Limit ideal for current sensitive applications. In dropout, the Internal 0.9 Power Switch: V = 9V IN internal P-channel MOSFET switch is turned on continu- Only Four External Components Required ously allowing the user to maximize the life of the battery 130A Standby Current source. Active Low Micropower Shutdown The maximum inductor current of the LTC1174 family is U pin selectable to either 340mA or 600mA, optimizing APPLICATIO S efficiency for a wide range of applications. Operation up to Distributed Power Systems 200kHz permits the use of small surface mount inductors Step-Down Converters and capacitors. Inverting Converters For applications requiring higher output current or ultra- Memory Backup Supply high efficiency, see the LTC1148 data sheet. Portable Instruments , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Battery-Powered Equipment All other trademarks are the property of their respective owners. TYPICAL APPLICATIO High Efficiency Step-Down Converter LTC1174-5 Efficiency 100 V IN 9V 15F* 95 + 6 V = 6V 25V IN V IN 3 3 8 90 LB SHUTDOWN IN V = 9V IN 2 1 LB V OUT OUT 85 7 5 5V I SW PGM 175mA 100H LTC1174-5 + 80 100F** GND 1N5818 10V L = 100H 4 75 V = 5V OUT 1174 TA01 I = 0V PGM * (3) AVX TPSD156K025 70 ** AVX TPSD107K010 1 10 100 200 COILTRONICS CTX100-4 LOAD CURRENT (mA) 1174 TA02 1174fe 1 EFFICIENCY (%) U ULTC1174 LTC1174-3.3/LTC1174-5 ABSOLUTE AXI U RATI GS (Note 1) (Voltage Referred to GND Pin) Operating Temperature Range Input Supply Voltage (Pin 6) LTC1174CX ............................................ 0C to 70C LTC1174 ........................................... 0.3V to 13.5V LTC1174IX ........................................ 40C to 85C LTC1174HV ...................................... 0.3V to 18.5V Junction Temperature (Note 2)............................ 125C Switch Current (Pin 5) .............................................. 1A Storage Temperature Range ................ 65C to 150C Switch Voltage (Pin 5) Lead Temperature (Soldering, 10 sec)................. 300C LTC1174 ................................................. V 13.5V IN LTC1174HV ............................................ V 18.5V IN UUW PACKAGE/ORDER I FOR ATIO TOP VIEW TOP VIEW V (V *) 1 8 SHUTDOWN V (V *) 1 8 SHUTDOWN OUT FB OUT FB LB 2 7 I LB 2 I OUT PGM 7 OUT PGM LB V 3 6 LB 3 6 V IN IN IN IN GND SW GND SW 4 5 4 5 S8 PACKAGE N8 PACKAGE 8-LEAD PLASTIC SO 8-LEAD PDIP * ADJUSTABLE OUTPUT VERSION * ADJUSTABLE OUTPUT VERSION T = 125C, = 150C/W T = 125C, = 110C/W JMAX JA JMAX JA ORDER PART NUMBER ORDER PART NUMBER S8 PART MARKING LTC1174CN8 LTC1174CS8 1174 LTC1174CN8-3.3 LTC1174CS8-3.3 117433 LTC1174CN8-5 LTC1174CS8-5 117450 LTC1174IN8 LTC1174IS8 1174I LTC1174HVCN8 LTC1174HVCS8 1174H LTC1174HVCN8-3.3 LTC1174HVCS8-3.3 1174H3 LTC1174HVCN8-5 LTC1174HVCS8-5 1174H5 LTC1174HVIS8 1174HI Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: