SRK1000BTR AC/DC Switching Converter Flyback, 300kHz,SOT-23-6

SRK1000 / SRK1000A /SRK1000B are controllers for secondary side synchronous rectification (SR) in flyback converters suitable for operation in QR and mixed CCM/DCM fixed frequency circuits. They provide a high current gate drive output capable of driving n-channel power MOSFETs. The control scheme of this IC is designed to turn on the SR MOSFET as soon as the current starts to flow through its body diode and turn it off when the current approaches zero.

The fast turn-on with minimum delay and the innovative adaptive turn-off logic allow maximizing the on-time of the SR-MOSFET and eliminating the effect of parasitic inductance in the circuit. The device switches to low power mode when it detects burst operation of the primary regulator or when the conductivity of the SR-MOSFET falls below the programmed minimum TON. This improves the efficiency of the converter at low loads where synchronous rectification is no longer advantageous.

After the converter starts switching again or the IC detects that the current flow in the rectifiers has increased by 20 % above the programmed minimum TON value, the IC exits the low consumption mode and resumes switching operation.