LT8315 560V Micropower No-Opto IN Isolated Flyback Converter with 630V/300mA Switch FEATURES DESCRIPTION n Wide Input Voltage Range: 18V to 560V The LT 8315 is a high voltage flyback converter with inte- n 630V/300mA Integrated Power Switch grated 630V/300mA switch. No opto-isolator is needed for n No Opto-Isolator Required for Regulation regulation. The device samples the output voltage from the n Quasi-Resonant Boundary Mode Operation isolated flyback waveform appearing across a third wind- n Constant-Current and Constant-Voltage Regulation ing on the transformer. Quasi-resonant boundary mode n Low Ripple Light Load Burst Mode Operation operation improves load regulation, reduces transformer n Low Quiescent Current: 70A size and maintains high efficiency. n Programmable Current Limit and Soft-Start At start-up, the LT8315 charges its INTV capacitor via a CC n TSSOP Package with High Voltage Spacing current source attached to the DRAIN pin. During normal operation, the current source turns off and the device draws its power from a third winding on the transformer. APPLICATIONS The LT8315 operates from a wide range of input supply n Isolated Telecom, Automotive, Industrial, Medical voltages and can deliver up to 15W of power. It is available Power Supplies in a thermally enhanced 20-pin TSSOP package with four n Isolated Off Line Housekeeping Power Supplies pins removed for high voltage spacing. n Electric Vehicles and Battery Stacks All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION 20V to 450V Isolated 12V Supply Efficiency IN IN OUT V 90 IN 20V TO 450V 0.44F 80 5:1:2 600 20k + V 70 640H OUT 12V 93.1k 47pF 60 200F 160H 10F BIAS DCM V = 50V IN 50 EN/UVLO FB V = 100V V OUT IN 4mH V = 150V 61.9k 5.11k IN INTV 5mA to 220mA (V = 50V) V = 250V CC IN 40 IN TC 5mA to 320mA (V = 100V) V = 350V IN LT8315 IN 10F 5mA to 380mA (V = 150V) V = 450V IN IN SMODE DRAIN 5mA to 440mA (V > 250V) 30 IN 0 100 200 300 400 500 LOAD CURRENT (mA) V SOURCE C 8315 TA01b 100k IREG/SS GND 330m 470pF 22nF 121k 8315 TA01a 8315fa 1 For more information www.linear.com/LT8315 EFFICIENCY (%)LT8315 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW DRAIN .....................................................................630V DRAIN 1 20 GND BIAS, EN/UVLO .........................................................40V DRAIN 2 19 NC INTV ......................................................................15V CC DRAIN 3 18 SOURCE SMODE ............................................................... INTV 17 EN/UVLO CC 21 16 SMODE SOURCE, TC, FB, V , IREG/SS ....................................4V C GND 15 GND DCM ...................................................................100mA 14 IREG/SS INTV 8 13 V CC C Operating Junction Temperature (Note 2) BIAS 9 12 FB LT8315E, LT8315I .............................. 40C to 125C DCM 10 11 TC LT8315H ............................................ 40C to 150C FE PACKAGE Storage Temperature Range .................. 65C to 150C 20(16)-LEAD PLASTIC TSSOP = 38C/W, = 10C/W Lead Temperature (Soldering, 10 sec) .................. 300 C JA JC EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION