LT1766/LT1766-5 5.5V to 60V 1.5A, 200kHz Step-Down Switching Regulator FEATURES DESCRIPTION n Wide Input Range: 5.5V to 60V The LT 1766/LT1766-5 are 200kHz monolithic buck switch- n 1.5A Peak Switch Current ing regulators that accept input voltages up to 60V. A high n Constant 200kHz Switching Frequency ef ciency 1.5A, 0.2 switch is included on the die along n Saturating Switch Design: 0.2 with all the necessary oscillator, control and logic circuitry. n Peak Switch Current Rating Maintained Over A current mode control architecture delivers fast transient Full Duty Cycle Range response and excellent loop stability. n Low Effective Supply Current: 2.5mA Special design techniques and a new high voltage process n Low Shutdown Current: 25A achieve high ef ciency over a wide input range. Ef ciency n 1.2V Feedback Reference Voltage (LT1766) is maintained over a wide output current range by using the n 5V Fixed Output (LT1766-5) output to bias the circuitry and by utilizing a supply boost n Easily Synchronizable capacitor to saturate the power switch. Patented circuitry n Cycle-by-Cycle Current Limiting maintains peak switch current over the full duty cycle range. n Small 16-Pin SSOP and Thermally Enhanced A shutdown pin reduces supply current to 25A and the TSSOP Packages device can be externally synchronized from 228kHz to 700kHz with logic-level inputs. APPLICATIONS The LT1766/LT1766-5 are available in a 16-pin fused-lead n High Voltage, Industrial and Automotive SSOP package or a TSSOP package with exposed backside n Portable Computers for improved thermal performance. n Battery-Powered Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Battery Chargers ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6498466, 6531909. n Distributed Power Systems TYPICAL APPLICATION 5V Buck Converter 1N4148W Ef ciency vs Load Current 6 0.33F 100 BOOST 47H V = 5V V OUT OUT 4 2 V * IN L = 47H V SW 5V V = 12V IN IN 5.5V TO 60V 2.2F 1A 90 100V 10MQ060N LT1766 + 100F 10V CERAMIC V = 42V SOLID IN 15 10 TANTALUM 80 SHDN BIAS OFF ON 15.4k 14 12 SYNC FB 70 GND V 4.99k C 1, 8, 9, 16 11 60 2.2k 220pF 50 0.022F 0 0.25 0.50 0.75 1.00 1.25 LOAD CURRENT (A) 1766 TA01 1766 TA02 *FOR INPUT VOLTAGES BELOW 7.5V, SOME RESTRICTIONS MAY APPLY TDK C4532X7R2A225K 1766fc 1 EFFICIENCY (%)LT1766/LT1766-5 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage (V ) .................................................. 60V Operating Junction Temperature Range IN LT1766EFE/LT1766EFE-5/LT1766EGN/ BOOST Pin Above SW .............................................. 35V BOOST Pin Voltage ................................................. 68V LT1766EGN-5 (Note 8,10) ....................40C to 125C LT1766IFE/LT1766IFE-5/ SYNC, SENSE Voltage (LT1766-5) ............................. 7V SHDN Voltage ............................................................ 6V LT1766IGN/LT1766IGN-5 (Note 8,10) ..40C to 125C LT1766HFE ..........................................40C to 140C BIAS Pin Voltage ..................................................... 30V FB Pin Voltage/Current (LT1766) ................... 3.5V/2mA Storage Temperature Range .................. 65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C PIN CONFIGURATION TOP VIEW TOP VIEW GND 1 16 GND GND 1 16 GND SW 2 15 SHDN SW 2 15 SHDN NC 3 14 SYNC NC 3 14 SYNC V 4 13 NC V 4 13 NC IN IN 17 GND NC 5 12 FB/SENSE NC 5 12 FB/SENSE BOOST 6 11 V BOOST 6 11 V C C NC 7 10 BIAS NC 7 10 BIAS GND 8 9 GND GND 8 9 GND FE PACKAGE GN PACKAGE 16-LEAD PLASTIC TSSOP 16-LEAD PLASTIC SSOP = 45C, (PIN 17) = 10C/W = 85C, (PIN 8) = 25C/W JA JC JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB FOUR CORNER PINS SOLDERED TO GROUND PIN 1766fc 2