The synchronous rectifier controller can be used in power supplies based on a flyback or resonant converter topology. It controls an external MOSFET, such as the 100V 16mΩ N-channel DMT10H015LPS, configured to operate as a diode. Replacing a Schottky rectifier with the ZXGD3113 MOSFET increases the efficiency of AC/DC power supplies, claims the company. Target applications are the industrial, consumer and telecommunications markets.

Efficiency negates the need for a heatsink, which saves space, compared with a lossy Schottky rectifier. The SOT26 reduces the form factor from the industry-standard SO8. Operating up to 250kHz, the power supply designer can use smaller transformers, further saving space and bill of material costs, points out the company.

Providing the control to a low R_DS(on) MOSFET, the controller achieves greater efficiency by using proportional gate drive, enabling it to rapidly turn off the synchronous MOSFET when operating in continuous conduction mode (CCM). The controller can also operate in discontinuous conduction mode (DCM) and critical conduction mode (CrCM). The controller also includes a low threshold voltage of less than 10mV to control the low R_DS(ON) MOSFET, and peak source/sink currents of 1.5/3A, respectively. A wide operating voltage range of 3.5 to 40V means the device can be driven directly by a power supply output as low as 3.5V, while giving sufficient headroom to handle over-voltage spikes or operate at higher V_cc rails such as 24V.

The ZXGD3113 synchronous rectifier controller and DMT10H015LPS MOSFET are available now.