Features and Benefits

  • +8V to +24V Input Range
  • +5V Input Range at Up to 7.2W Output Power
  • Output Voltages
    • VOUT1 = -72V at 100mA
    • VOUT2 = -24V at 400mA
  • Configurable for -48V at 200mA Output
  • 100kHz to 500kHz Switching Frequency
  • External Frequency Control
  • Low-Cost Minimum Components with Flyback Design
  • Fully Assembled and Tested

Product Details

The MAX1856 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains an inverting transformer flyback DC-DC converter. The circuit is configured for two output voltages simultaneously: a -72V that can supply up to 100mA, and a -24V that can supply up to 400mA. The input voltage may range from +8V to +24V. The circuit can be configured for -48V, and supply up to 200mA. When operating from a +5V input supply, the circuit can deliver up to 7.2W output power in either configuration.

The MAX1856 EV kit switching frequency is set at 250kHz but can range from 100kHz to 500kHz switching frequency or may be driven by an external clock. The MAX1856 EV kit demonstrates low quiescent current and high efficiency (over 80%). The MAX1856 comes in the 10-pin µMAX package.


  • Cable and DSL Modems
  • CO DSL Line Driver Supplies
  • FTTH
  • Industrial Power Supplies
  • MEMS Bias Supplies
  • Routers/Switches
  • Set-Top Boxes
  • VoIP Ringer and Off-Hook Voltage Generators
  • Wireless Local Loop (WLL)

Applicable Parts

Documentation & Resources