LT1766/LT1766-5 5.5V to 60V 1.5A, 200kHz Step-Down Switching Regulator FEATURESDESCRIPTION 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 effi ciency 1.5A, 0.2Ω switch is included on the die along n Saturating Switch Design: 0.2Ω 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: 25μA achieve high effi ciency over a wide input range. Effi 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 25μA and the TSSOP Packages device can be externally synchronized from 228kHz to APPLICATIONS 700kHz with logic-level inputs. 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 n Battery Chargers L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property n Distributed Power Systems of their respective owners. Protected by U.S. Patents, including 6498466, 6531909. TYPICAL APPLICATION5V Buck Converter 1N4148W Effi ciency vs Load Current 6 0.33μF 100 BOOST 47μH V 4 2 VOUT OUT = 5V VIN* V L = 47μH IN SW 5V V 5.5V TO 60V IN = 12V 2.2μF† 1A 90 100V 10MQ060N LT1766 + 100μF 10V CERAMIC SOLID VIN = 42V 15 10 OFF ON SHDN BIAS TANTALUM 80 15.4k 14 12 SYNC FB 70 GND V EFFICIENCY (%) C 4.99k 1, 8, 9, 16 11 60 2.2k 220pF 50 0.022μF 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