LTC1872 Constant Frequency Current Mode Step-Up DC/DC Controller in SOT-23 Fea T Descrip T n High Efficiency: Over 90% The LTC 1872 is a constant frequency current mode step- n High Output Currents Easily Achieved up DC/DC controller providing excellent AC and DC load n Wide V Range: 2.5V to 9.8V and line regulation. The device incorporates an accurate IN n V Limited Only by External Components undervoltage lockout feature that shuts down the LTC1872 OUT n Constant Frequency 550kHz Operation when the input voltage falls below 2.0V. n Burst Mode Operation at Light Load The LTC1872 boasts a 2.5% output voltage accuracy n Current Mode Operation for Excellent Line and Load and consumes only 270A of quiescent current. For ap- Transient Response plications where efficiency is a prime consideration, the n Low Quiescent Current: 270A LTC1872 is configured for Burst Mode operation, which n Shutdown Mode Draws Only 8A Supply Current enhances efficiency at low output current. n 2.5% Reference Accuracy n In shutdown, the device draws a mere 8A. The high Tiny 6-Lead SOT-23 Package 550kHz constant operating frequency allows the use of a small external inductor. a T The LTC1872 is available in a small footprint 6-lead n Lithium-Ion-Powered Applications SOT-23. n Cellular Telephones L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective n Wireless Modems owners. n Portable Computers n Scanners Typical a T Efficiency vs Load Current V IN 3.3V 100 C1 R1 V = 3.3V IN 10F 0.03 V = 5V OUT 10V 95 147k 1 5 L1 I /RUN V TH IN 90 4.7H LTC1872 220pF V OUT 2 4 85 5V GND SENSE + C2 80.6k 1A 3 6 D1 V NGATE M1 2 22F FB 80 6.3V 75 422k 70 C1: TAIYO YUDEN CERAMIC EMK325BJ106MNT C2: MURATA GRM42-2X5R226K6.3 D1: IR10BQ015 65 L1: MURATA LQN6C4R7M04 1 10 100 1000 M1: IRLMS2002 LOAD CURRENT (mA) 1872 TA01 R1: DALE 0.25W 1872 TA01b Figure 1. LTC1872 High Output Current 3.3V to 5V Boost Converter 1872fa 1 For more information www.linear.com/LTC1872 EFFICIENCY (%) ion pplica ions pplica ion uresLTC1872 a Te Maxi Mu M r a T p in c F T (Note 1) Input Supply Voltage (V ) ......................... 0.3V to 10V IN TOP VIEW SENSE , NGATE Voltages ............. 0.3V to (V + 0.3V) IN I /RUN 1 6 NGATE TH V , I /RUN Voltages .............................. 0.3V to 2.4V FB TH GND 2 5 V IN NGATE Peak Output Current (<10s) ........................ 1A V 3 4 SENSE FB Storage Ambient Temperature Range ....65C to 150C S6 PACKAGE Operating Temperature Range (Note 2)....40C to 85C 6-LEAD PLASTIC SOT-23 T = 150C, = 230C/W JMAX JA Junction Temperature (Note 3) ............................ 150C Lead Temperature (Soldering, 10 sec) ...................300C o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1872ES6 PBF LTC1872ES6 TRPBF LTMK 6-Lead Plastic SOT-23 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: