The MAX17690A evaluation kit (EV kit) is a fully assembled and tested circuit board that demonstrates the operation of an isolated 5W no-opto flyback DC-DC converter with secondary-side synchronous rectification. This circuit is implemented using the MAX17690, a no-opto, flyback controller in a 16-pin TQFN package with an exposed pad. The synchronous rectification on the secondary side is enabled by replacing the secondary diode with a MOSFET to achieve 90% efficiency. The circuit uses the MAX17606, a secondary-side synchronous rectifier driver in a 6-pin SOT23 package for driving the secondary-side MOSFET.
The EV kit output is configured for an isolated +5V and provides up to 1A of output current. The EV kit is programmed to operate at a 150kHz switching frequency. The transformer provides the galvanic isolation between input and output, up to 1875VRMS. The EV kit regulates the output voltage within ±5% over the line, load, and temperature without using the auxiliary winding/optocoupler for output voltage feedback.