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 Linear Technology LT3439 is a push-pull DC/DC transformer driver designed to reduce conducted and radiated electromagnetic interference (EMI). It features two 1A current-limited power switches with user-adjustable slew rates for output voltage and current, helping to optimize noise versus efficiency. The device includes cross-conduction prevention circuitry and protection against overcurrent and overtemperature conditions.
| Supply Operating Range | 2.8V to 17.5V |
|---|---|
| Shutdown Current | <20uA |
| Switch Current Limit | 1.4A |
| Oscillator Frequency | 250 kHz |
The device operates down to a minimum input voltage of 2.55V.
The frequency is set using an external resistor (Ry) and capacitor (C7).
The output switches have a typical breakdown voltage of 50V.