MAXREFDES1170: 24V/100mA output, ISO-BUCK DC-DC power module

The MAXREFDES1170 is a high-efficiency, iso-buck DC-DC power module based on the MAX17681. It accepts an input voltage range from 17V to 32V and adjusts the output voltage through primary-side feedback. The reference design provides 24V@100mA output with a voltage regulation accuracy of ±8%. This iso-buck isolated power module is designed using the MAX17681 in a 10-pin (3mm x 2mm) TDFN package. The MAXREFDES1170's pin spacing complies with the Distributed Power Source Open Standards Alliance's (DOSA) open standard for DC/DC module power supplies. Two transformer options are provided, one is from Wurth; the other is from Chinese transformer manufacturer HanRun, which is convenient for users to choose. The small size of 20mm x 40mm makes it easy for users to transplant it to end products or mount it directly to circuit boards. The reference design provides 1500V electrical isolation.

Key Features

• 24V@100mA output, output voltage ripple 320mV

• 17V to 32V input voltage range

• Small size: 20mm x 40mm

• EN/UVLO input

• 200kHz switching frequency

• 92% peak efficiency

• Overcurrent protection

• No optocoupler design

• Output power up to 2.4W

• Thermal Protection

• Proven PCB layout

This circuit board is not for sale.

Design, build and test

This reference design introduces the MAXREFDES1170 hardware circuit design and provides detailed technical guidance for designing iso-buck converters using Maxim's MAX17681A current-mode controller. The power supply has been built and tested.

design resources