ST introduces flexible synchronous rectifier controllers to improve the energy efficiency of silicon-based or gallium nitride power converters

     The ST SRK1004 Synchronous rectifier controller simplifies the design of power converters using silicon-based or GaN transistors and improves conversion efficiency for applications including industrial power supplies, portable device chargers and AC/DC adapters.

     The SRK1004's detection input can withstand voltages up to 190V and can be connected to high-low power switch tubes. With four products to choose from, the device selection alone allows users to optimize the application design. By choosing a gate drive voltage of 5.5V or 9V, you can choose the ideal logic level MOSFET, standard MOSFET or GaN transistor in the design, avoiding complex calculations. Suitable for non-complementary active clamp, resonant and quasi-resonant (QR) flyback topologies, the SRK1004 introduces a new generation of turn-off algorithms that simplify switching operation and save power.

     This controller allows the power converter to be reduced in size while increasing the rated output power. The maximum switching frequency of 500kHz allows for the use of small electromagnetic components and, when GaN transistors are used, also maximizes the benefits of wide-band gap technology. Using ST's Silicon on Insulator (SOI) manufacturing process, the controller is available in a 2mm x 2mm DFN-6L micro-package while ensuring excellent robustness.

     The SRK1004 has a power supply voltage of 4V to 36V and can use a variety of standard industrial bus power supplies. The wide voltage input also allows the flexibility to adjust the step-down ratio for optimal energy efficiency. In addition, the controller has built-in fast short-circuit detection, which helps to develop robust and reliable devices.

     Of the four new products, the SRK1004A and SRK1004B have a gate drive voltage of 5.5V and can be used with logic level MOSFET or GaN transistors. The SRK1004C and SRK1004D with a 9V gate drive voltage are suitable for MOSFETs with standard gate drive signals.

     The SRK1004x synchronous rectifier controller is now in mass production. Four product evaluation boards, EVLSRK1004A, EVLSRK1004B, EVLSRK1004C and EVLSRK1004D, are now available to help developers speed up the product evaluation process and start designing early.