
Linear Technology
DESCRIPTION
The LT® 3439 is a push-pull DC/DC transformer driver that reduces conducted and radiated electromagnetic interfer ence (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.
FEATURES
■ 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
■ 20kHz to 250kHz Oscillator Frequency
■ Synchronizable to 300kHz
■ Overcurrent and Overtemperature Protected
APPLICATIONS
■ Low Noise Isolated Supplies
■ Radio and Telecom Supplies
■ Distributed Supplies
■ Medical Instruments
■ Precision Instruments
■ Low Noise Filament Supplies