描述 Description

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 MOSFET. Each gate driver is controlled separately, and an interlock logic circuit prevents the two synchronous rectifier MOSFET from conducting simultaneously.

The driver high-level voltage is clamped to 11 V in order to avoid delivering excessive gate charge to the SR MOSFET when the device is supplied at higher VCC voltages.

The control scheme ensures that each synchronous rectifier is switched ON as the corresponding half-winding starts conducting and OFF as its current falls 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 MOSFET, eliminating the need for a parasitic inductance compensation circuit.

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

A very low external component count required when using this device.

特性 Features

? Secondary side synchronous rectification controller optimized for LLC resonant converter
? Dual gate driver for N-channel MOSFETs
? Adaptive turn-off logic
? Turn-on logic with adaptive masking time
? Auto-compensation of parasitic inductance
? Low consumption mode: 50 μA quiescent current
? VCC operating voltage range 4.5 V to 32 V
? High voltage drain-to-source Kelvin sensing for each SR MOSFET
? Operating frequency up to 500 kHz
? Programmable exit load levels from burst- mode
? SSOP10 package