The ISL6740EVAL3Z serves as a reference design for a 48V to ±12V, 3.3V and 1.5V isolated power supply. It utilizes an ISL6740 double-ended voltage mode controller in half bridge topology to provide an isolated 48V to ±12V conversion. An ISL6402 dual PWM controller in synchronous buck topology provides the 3.3V and 1.5V outputs from the +12V rail. The reference design also provides pads to implement an optional LDO using the ISL6402 as a controller.

The ISL6740 adjustable frequency, low power, pulse width modulating (PWM) voltage mode controllers are designed for a wide range of power conversion applications using half-bridge, full bridge, and push-pull configurations. These controllers provide an extremely flexible oscillator that allows precise control of frequency, duty cycle, and deadtime.

The boards are designed to operate at the following conditions:

• Input Voltage: 36V to 72V
• Outputs:
  • 3.3V ±1% @ 4A
  • 1.5V ±1% @ 7A
  • 12V +3.5%/-10% (typical) @ 1.5A
  • -12V +3.5%/-10% (typical) @ 1.5A
• Efficiency at full load: 86.8% (72V input) to 90.3% (36V input)

• Telecom and Datacom Power
• Wireless Base Station Power
• File Server Power
• Industrial Power Systems
• DC Transformers and Buss Regulators