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Transformer Driver for Isolated Power Supplies

Isolated Supply

Transformer Driver

Engineering Samples


  • Spread spectrum clocking for lower EMI
  • Low Pulse Width Distortion < 1.5ns
  • In-rush and magnetic control through pulse-skipping, duty cycle and frequency adjustment
  • D1 & D2 up to 30V operation
  • Up to 350mA D1 & D2 drive
  • 400kHz Free running frequency
  • 5-Pin SOT-23 Package (engineering samples in SOIC8)
  • Voltage supply range 4.5V to 5.5V
  • 2kV ESD Protection
  • Wide Temperature Range -55°C to 150°C


  • Push-pull driver for small transformers
  • Isolated DCDC power supply
  • Isolated power supply for high side driver
  • High-Temperature Environments


The NZL-300 is a monolithic oscillator/power-driver, specifically designed for small form factor, isolated power supplies in isolated interface applications. The device drives a low-profile, center-tapped transformer primary from a 3-5.5V power supply. The secondary can be wound to provide any isolated voltage based on transformer turns ratio. The NZL-300 consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive the ground referenced N-channel power switches. The internal logic ensures non-overlapping (break-before-make) and controls duty cycle between the two switches in order to ensure perfect magnetic balance on the transformer. At startup the NZL-300 features inrush and magnetization control by innovative pulse skipping and frequency adjustment. The NZL-300 has reduced EMI signature thanks to its spread spectrum clock. The NZL-300 is available in a small SOT-23 (5L) package, and is specified for operation at temperatures from –55°C to 150°C.

Demo boards with the NZL-300

  • EVK01

    Isolated high-voltage buck-converter evaluation board.
    It highlights the use of VDDTECH’s IZL-100 digital isolator, IZL-200 error amplifier and NZL-300 transformer driver.