Linear Tech transformer driver provides low noise, EMI

The LT3439 1A isolated push-pull dc/dc transformer driver from Linear Technology Corp. provides low noise and EMI by using a single resistor to control both the output switch voltage and current slew rates.

The company claims that the device can reduce HF harmonic content by as much as 40dB with only a slight decrease in efficiency.

The 16-lead thermally-enhanced TSSOP can accommodate 2.8V to 17.5V to drive an external, center-tapped transformer, which in turn supplies an isolated output. The actual output voltage is defined by the transformer turns ratio.

The LT3439 utilizes two 1A current-limited power switches at a 50 percent push-pull duty cycle. It has an internal oscillator that can be synchronized to an external clock for more accurate placement of switching harmonics.

Protection features include current limiting, undervoltage lockout, thermal shutdown, and cross conduction prevention circuitry.

Pricing starts at $3.50 each for 1,000-piece quantities.