Slew Rate Controlled Ultralow Noise 1A Isolated DC/DC Transformer Driver

The LT3439 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 40dB 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.

Applications

* Low Noise Isolated Supplies

* Radio and Telecom Supplies

* Distributed Supplies

* Medical Instruments

* Precision Instruments

* Low Noise Filament Supplies

* 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