LT3430/LT3430-1 High Voltage, 3A, 200kHz/100kHz Step-Down Switching Regulators FEATURES DESCRIPTION Wide Input Range: 5.5V to 60V The LT 3430/LT3430-1 are monolithic buck switching 3A Peak Switch Current over All Duty Cycles regulators that accept input voltages up to 60V. A high ef- Constant Switching Frequency: ciency 3A, 0.1 switch is included on the die along with 200kHz (LT3430) all the necessary oscillator, control and logic circuitry. A 100kHz (LT3430-1) current mode architecture provides fast transient response 0.1 Switch Resistance and excellent loop stability. Current Mode Special design techniques and a new high voltage process Effective Supply Current: 2.5mA achieve high ef ciency over a wide input range. Ef ciency Shutdown Current: 30A is maintained over a wide output current range by using 1.2V Feedback Reference Voltage the output to bias the circuitry and by utilizing a supply Easily Synchronizable boost capacitor to saturate the power switch. Patented Cycle-by-Cycle Current Limiting circuitry* maintains peak switch current over the full duty Small, 16-Pin Thermally Enhanced TSSOP Package cycle range. A shutdown pin reduces supply current to 30A and a SYNC pin can be externally synchronized with APPLICATIONS a logic level input from 228kHz to 700kHz for the LT3430 Industrial and Automotive Power Supplies or from 125kHz to 250kHz for the LT3430-1. Portable Computers The LT3430/LT3430-1 are available in a thermally enhanced Battery Chargers 16-pin TSSOP package. Distributed Power Systems , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. *US Patent 6498466 TYPICAL APPLICATION 5V, 2A Buck Converter Ef ciency vs Load Current 100 MMSD914TI V = 5V OUT V = 12V IN 90 0.68F BOOST V 22H V IN OUT 5.5V* V SW 5V IN 80 V = 42V TO 60V 2A IN 30BQ060 4.7F LT3430** 100V + 100F 10V 70 SOLID OFF ON SHDN BIAS TANTALUM 15.4k 60 SYNC FB LT3430-1 L = 68H GND V 4.99k C LT3430 L =27H 50 0 0.5 1.0 1.5 2.0 2.5 LOAD CURRENT (A) 220pF 3.3k 3430 TA02 0.022F 3430 TA01 *FOR INPUT VOLTAGES BELOW 7.5V, SOME RESTRICTIONS MAY APPLY ** SEE LT3430-1 CIRCUIT IN APPLICATIONS INFORMATION SECTION 34301fa 1 EFFICIENCY (%)LT3430/LT3430-1 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Note 1) TOP VIEW Input Voltage (V ) .................................................. 60V IN GND 1 16 GND BOOST Pin Above SW (Note 11) .............................. 35V SW 2 15 SHDN BOOST Pin Voltage ................................................. 68V V 3 14 SYNC IN SYNC Voltage ............................................................. 7V V 4 13 NC IN 17 SHDN Voltage ............................................................ 6V SW 5 12 FB BIAS Pin Voltage ..................................................... 30V BOOST 6 11 V C FB Pin Voltage/Current .................................. 3.5V/2mA NC 7 10 BIAS Operating Junction Temperature Range GND 8 9 GND LT3430EFE (Notes 8, 10) .................. 40C to 125C FE PACKAGE 16-LEAD PLASTIC TSSOP LT3430IFE (Notes 8, 10) .................. 40C to 125C T = 125C, = 45C/W, = 10C/W JMAX JA JC Storage Temperature Range ................. 65C to 150C EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB Lead Temperature (Soldering, 10 sec) ................ 300C ORDER PART NUMBER FE PART MARKING LT3430EFE 3430EFE LT3430IFE 3430IFE LT3430EFE-1 3430EFE-1 LT3430IFE-1 3430IFE-1 Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: