STEVAL-SCR001V1 Inrush current solution with bypass SCR

The STEVAL-SCR001V1 is a low cost evaluation board for testing ST inrush current limitation solutions.

Based on an analog control circuit with only discrete components, it offers a compact and reliable alternative to relays to bypass inrush current limiting resistors in power converters.

Its drive circuit is self-synchronized to the AC line. Working in pulsed mode, it allows low gate drive consumption and no SCR reverse losses. Additionally, the 50 mA SCR TN5015H-6G provides better immunity to Electrical Fast Transients (EFT).

The power supply of the circuit can be created from a secondary winding of a PFC or an auxiliary power supply used to drive transistor and power the system MCU. With no adjustment needed when 12 V unregulated power is supplied, and only 5 wires to connect, this board can be easily implemented on existing PFC or fly-back converters.

It is suitable for applications with peak current up to 5 A (at 60 °C ambient temperature)