LT3958 High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter Fea T Descrip T n Wide Input Voltage Range: 5V to 80V The LT 3958 is a wide input range, current mode, DC/DC n Single Feedback Pin for Positive or Negative converter which is capable of generating either positive Output Voltage or negative output voltages. It can be configured as either n Internal 3.3A/84V Power Switch a boost, flyback, SEPIC or inverting converter. It features n Current Mode Control Provides Excellent Transient an internal low side N-channel power MOSFET rated for Response 84V at 3.3A and driven from an internal regulated 7.2V n Programmable Operating Frequency (100kHz to supply. The fixed frequency, current-mode architecture 1MHz) with One External Resistor results in stable operation over a wide range of supply n Synchronizeable to an External Clock and output voltages. n Low Shutdown Current < 1A The operating frequency of LT3958 can be set with an n Internal 7.2V Low Dropout Voltage Regulator external resistor over a 100kHz to 1MHz range, and can n Programmable Input Undervoltage Lockout with be synchronized to an external clock using the SYNC pin. Hysteresis A minimum operating supply voltage of 5V, and a low n Programmable Soft-Start shutdown quiescent current of less than 1A, make the n Thermally Enhanced QFN (5mm 6mm) Package LT3958 ideally suited for battery-powered systems. The LT3958 features soft-start and frequency foldback a T functions to limit inductor current during start-up. n Automotive L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No R and ThinSOT are trademarks of Analog Devices, Inc. All other trademarks are the SENSE n Telecom property of their respective owners. Patents pending. n Industrial Typical a T High Efficiency Boost Converter Efficiency vs Output Current 33H V OUT 100 V IN 48V V = 24V IN 12V TO 40V 0.5A 4.7F 4.7F 95 V SW 392k IN 2 EN/UVLO GND 90 53.6k LT3958 85 SGND SENSE1 464k SYNC SENSE2 80 FBX RT SS VC INTV 75 CC 15.8k 41.2k 10k 0.33F 4.7F 70 300kHz 0 100 200 300 400 500 10nF OUTPUT CURRENT (mA) 3958 TA01b 3958 TA01a 3958fa 1 For more information www.linear.com/LT3958 EFFICIENCY (%) ion pplica ions pplica ion uresLT3958 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW V , EN/UVLO (Note 5) ..............................................80V IN SW ............................................................................84V INTV .................................................... V + 0.3V, 15V CC IN 36 35 34 33 32 31 30 SYNC ..........................................................................8V NC 1 28 INTV CC VC, SS .........................................................................3V NC V 2 27 IN RT 1.5V SENSE2 3 37 ............................................................................................... SGND SGND 4 25 EN/UVLO SENSE1, SGND .................. Internally Connected to GND 24 SGND SENSE2 ..................................................................0.3V SENSE1 6 23 SGND FBX ................................................................. 6V to 6V Operating Temperature Range 38 SW 8 21 SW SW (Note 2) ............................................. 40C to 125C SW 9 20 SW Maximum Junction Temperature........................... 125C NC 10 12 13 14 15 16 17 Storage Temperature Range ................... 65C to 125C UHE PACKAGE 36-LEAD (5mm 6mm) PLASTIC QFN T = 125C, = 43C/W, = 5C/W JMAX JA JC EXPOSED PAD (PIN 37) IS SGND, MUST BE SOLDERED TO SGND PLANE EXPOSED PAD (PIN 38) IS SW, MUST BE SOLDERED TO SW PLANE o r Der i n F Ma T