LT3439 Datasheet | Linear Technology

LT3439 Slew Rate Controlled Ultralow Noise1A Isolated DC/DC Transformer Driver .. Features s s DESCRIPTIO s s s s s s s s Reduced Conducted and Radiated EMI Single Resistor Control of Output Switch Voltage and Current Slew Rates Cross Conduction Prevention Circuitry Two 1A Current Limited Power Switches Low Minimum Supply Voltage: 2.8V Low Shutdown Current: < 20µA 50% Duty Cycle 20k Hz to 250k Hz Oscillator Frequency Synchronizable to 300k Hz Overcurrent and Overtemperature Protected The LT®3439 is a push-pull DC/DC transformer driver that reduces conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are achieved by controlling the output switch voltage and current slew rates. Slew rates are user adjustable to optimize output noise versus efficiency. The LT3439 can reduce high frequency harmonic content by as much as 40d B with only a minor decrease in efficiency. The LT3439 includes two 1A current limited power switches to ensure start-up under heavy loads. It also includes an oscillator that can be synchronized to an external clock for more accurate placement of switcher harmonics. Protection Features include current limiting, undervoltage lockout, thermal shutdown and cross conduction prevention circuitry. The LT3439 is available in a thermally enhanced 16-pin TSSOP with an exposed backside. , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S s s s s s s Low Noise Isolated Supplies Radio and Tele Supplies Distributed Supplies Medical Instruments Precision Instruments Low Noise Filament Supplies TYPICAL APPLICATIO Low Noise 5V to 5V Push-Pull DC/DC Transformer 5V Output Noise OPTIONAL VIN 5V T1 CIN 22µF 10V 13 11 5 6 680p F 7 16.9k VIN SHDN SYNC CT RT GND 10 RSL PGND 1, 16 3439 TA01 D1 A C1 47µF 6.3V L1 33µH C2 47µF 6.3V - 3 - - VOUT 5V 500m A COL A LT3439 COL B - 14 4 34k B 200µV/DIV D2 CIN: MURATA GRM235Y5V226Z10 C1, C2: TDK C4532X5R0J476M D1, D2: MBR0520 L1:...