LTC1772CS6#TRMPBF Analog Devices

LTC1772 Constant Frequency Current Mode Step-Down DC/DC Controller in SOT-23 FEATURES DESCRIPTIO High Efficiency: Up to 94% The LTC 1772 is a constant frequency current mode step- High Output Currents Easily Achieved down DC/DC controller providing excellent AC and DC load Wide V Range: 2.5V to 9.8V and line regulation. The device incorporates an accurate IN Constant Frequency 550kHz Operation undervoltage lockout feature that shuts down the LTC1772 Burst Mode Operation at Light Load when the input voltage falls below 2.0V. Low Dropout: 100% Duty Cycle The LTC1772 provides a 2.5% output voltage accuracy Tiny 6-Lead SOT-23 Package and consumes only 270A of quiescent current. For 0.8V Reference Allows Low Output Voltages applications where efficiency is a prime consideration, the Current Mode Operation for Excellent Line and Load LTC1772 is configured for Burst Mode operation, which Transient Response enhances efficiency at low output current. Low Quiescent Current: 270A To further maximize the life of a battery source, the Shutdown Mode Draws Only 8A Supply Current external P-channel MOSFET is turned on continuously in 2.5% Reference Accuracy dropout (100%dutycycle).In shutdown, the device draws U APPLICATIO S a mere 8A. High constant operating frequency of 550kHz allows the use of a small external inductor. One or Two Lithium-Ion-Powered Applications The LTC1772 is available in a small footprint 6-lead Cellular Telephones SOT-23. Wireless Modems , LTC and LT are registered trademarks of Linear Technology Corporation. Portable Computers Burst Mode is a registered trademark of Linear Technology Corporation. Distributed 3.3V, 2.5V or 1.8V Power Systems All other trademarks are the property of their respective owners. Scanners TYPICAL APPLICATIO V Efficiency vs Load Current IN 2.5V 100 C1 TO 9.8V R1 V = 4.2V IN 10F 0.03 V = 3.3V IN 10V 90 1 6 L1 I /RUN PGATE M1 TH 4.7H V OUT 80 2.5V LTC1772 10k V = 6V + C2A C2B IN 2 5 2A GND V D1 IN 47F 1F 70 V = 8.4V 3 4 IN 220pF 6V 10V 174k V = 9.8V V SENSE IN FB 60 C1: TAIYO YUDEN LMK325BJ106K-T C2A: SANYO 6TPA47M 50 80.6k C2B: AVX 0805ZC105KAT1A V = 2.5V D1: MOTOROLA MBRM120T3 OUT 40 L1: MURATA LQN6C-4R7 1 10 100 1000 10000 M1: FAIRCHILD FDC638P 1772 F01a R1: IRC LRC-LR1206-01-R030F LOAD CURRENT (mA) 1772 F01b Figure 1. High Efficiency, High Output Current 2.5V/2A Regulator 1772fb 1 EFFICIENCY (%) U ULTC1772 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Note 1) ORDER PART NUMBER Input Supply Voltage (V ).........................0.3V to 10V IN LTC1772CS6 SENSE , PGATE Voltages ............. 0.3V to (V + 0.3V) IN TOP VIEW LTC1772ES6 V , I /RUN Voltages .............................0.3V to 2.4V FB TH I /RUN 1 6 PGATE TH LTC1772IS6 PGATE Peak Output Current (<10s) ......................... 1A GND 2 5 V IN LTC1772HS6 Storage Ambient Temperature Range ... 65C to 150C V 3 4 SENSE FB Operating Temperature Range S6 PART MARKING S6 PACKAGE LTC1772CS6 ........................................... 0C to 70C 6-LEAD PLASTIC SOT-23 LTIL LTC1772ES6 (Note 2) ........................ 40C to 85C = 230C/ W JA LTIM LTC1772IS6 (Note 2) ......................... 40C to 85C LTB7 LTC1772HS6 (Notes 2,3) ................. 40C to 140C LTBRY Junction Temperature (Note 3)............................. 150C Order Options Tape and Reel: Add TR Lead Temperature (Soldering, 10 sec).................. 300C Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: