LTC1871-7 High Input Voltage, Current Mode Boost, Flyback and SEPIC Controller Fea T Descrip T n Optimized for High Input Voltage Applications The LTC 1871-7 is a current mode, boost, flyback and n Wide Chip Supply Voltage Range: 6V to 36V SEPIC controller optimized for driving 6V-rated MOSFETs n Internal 7V Low Dropout Voltage Regulator in high voltage applications. The LTC1871-7 works equally Optimized for 6V-Rated MOSFETs well in low or high power applications and requires few n Current Mode Control Provides Excellent components to provide a complete power supply solution. Transient Response The switching frequency can be set with an external resistor n High Maximum Duty Cycle (92% Typ) over a 50kHz to 1MHz range, and can be synchronized to n 2% RUN Pin Threshold with 100mV Hysteresis an external clock using the MODE/SYNC pin. Burst Mode n 1% Internal Voltage Reference operation at light loads, a low minimum operating supply n Micropower Shutdown: I = 10A voltage of 6V and a low shutdown quiescent current of Q n Programmable Operating Frequency 10A make the LTC1871-7 well suited for battery-operated (50kHz to 1MHz) with One External Resistor systems. For applications requiring constant frequency n Synchronizable to an External Clock Up to 1.3 f operation, Burst Mode operation can be defeated using OSC n User-Controlled Pulse Skip or Burst Mode Operation the MODE/SYNC pin. The LTC1871-7 is available in the n Output Overvoltage Protection 10-lead MSOP package. n Can be Used in a No R Mode for V < 36V SENSE DS PARAMETER LTC1871-7 LTC1871 n Small 10-Lead MSOP Package INTV 7.0V 5.2V CC + INTV UV 5.6V 2.1V CC a T INTV UV 4.6V 1.9V CC n Telecom Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. No R is a trademark of Linear Technology Corporation. n SENSE 42V Automotive Systems All other trademarks are the property of their respective owners. n 24V Industrial Controls n IP Phone Power Supplies Typical a T D3 10BQ060 V OUT V IN 12V 36V TO 72V 2.2F 3:1 0.4A 604k 100k 100V 47F 26.7k T1 X7R Q1 16V VP1-0076 FMMT625 X5R D1 9.1V 10 2.2nF RUN SENSE D2 I V TH IN 4148 3.4k LTC1871-7 FB INTV CC M1 12.4k FREQ GATE FDC2512 MODE/SYNC GND 0.1F 4.7F 0.12 110k 120k X5R X5R 18717 F01 Figure 1. Small, Nonisolated 12V Flyback Telecom Housekeeping Supply 18717fd 1 ion pplica ions pplica ion uresLTC1871-7 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW V Voltage ............................................... 0.3V to 36V IN RUN 1 10 SENSE INTV Voltage ........................................... 0.3V to 9V CC I 2 9 V TH IN FB 3 8 INTV INTV Output Current...........................................50mA CC CC FREQ 4 7 GATE GATE Voltage ........................... 0.3V to V + 0.3V MODE/ 5 6 GND INTVCC SYNC I , FB Voltages ....................................... 0.3V to 2.7V MS PACKAGE TH 10-LEAD PLASTIC MSOP RUN Voltage................................................ 0.3V to 7V T = 125C, = 120C/W JMAX JA MODE/SYNC Voltage ................................... 0.3V to 9V FREQ Voltage ............................................ 0.3V to 1.5V SENSE Pin Voltage .................................... 0.3V to 36V Operating Temperature Range (Note 2) LTC1871E-7 ..........................................40C to 85C LTC1871I-7 ......................................... 40C to 125C Junction Temperature (Note 3) ............................. 125C Storage Temperature Range .................. 65C to 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 LTC1871EMS-7 PBF LTC1871EMS-7 TRPBF LTG4 10-Lead Plastic MSOP 40C to 85C LTC1871IMS-7 PBF LTC1871IMS-7 TRPBF LTBTR 10-Lead Plastic MSOP 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1871EMS-7 LTC1871EMS-7 TR LTG4 10-Lead Plastic MSOP 40C to 85C LTC1871IMS-7 LTC1871IMS-7 TR LTBTR 10-Lead Plastic MSOP 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: