SRK2001A Active

The SRK2001A controller implements a control scheme specific for secondary side synchronous rectification in LLC resonant converters that use a transformer with center tap secondary winding for full wave rectification.

It provides two high current gate drive outputs, each capable of directly driving N-channel power MOSFETs. Each gate driver is controlled separately and an interlock logic circuit prevents the two synchronous rectifier MOSFETs from conducting simultaneously.

The driver high-level voltage is clamped to 11 V in order to avoid providing excessive gate charge to SR MOSFETs, in case the device is supplied at higher VCC voltages.

The control scheme in this IC provides for each synchronous rectifier being switched on as the corresponding half-winding starts conducting and switched off as its current goes to zero.

The turn-on logic with adaptive masking time (up to 10% of clock cycle) and innovative adaptive turn-off logic allow maximizing the conduction time of the SR MOSFETs, eliminating the need of the parasitic inductance compensation circuit.

The low consumption mode of the device allows to meet the most stringent requirement for converter power consumption in light-load and no load conditions.

A noticeable feature is the very low external component count required.