Features

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Synchronous rectifier for flyback converter, with fixed turn-on and adaptive turn-

off

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Vcc range: 3.5 V to 32 V

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DVS sensing voltage: 185V AMR

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Max frequency: 500 kHz

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Internal gate drive for N-channel MOSFET

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SR MOSFET type: FDPF190N15A (150 V – 19 mΩ) TO220FP

Description

The EVLSRK1001-TO is a demonstration board, designed for evaluation of the

SRK1001 synchronous rectification controller.

The SRK1001 implements a control scheme specific for secondary-side synchronous

rectification in flyback converters and provides high-current gate-drive outputs for

driving N-channel Power MOSFET.

The device can operate both in quasi-resonant (QR) applications and in fixed

frequency (FF) mixed DCM-CCM applications. The board is provided with a setting

suitable for QR application. To use in FF applications, a 100 pF capacitor needs to be

added in C3. A 120 kΩ resistor (R3) is provided on the TON pin that fixes the

blanking after the turn-on to about 1.44 µs. The blanking time after turn-off is set to 3

μs through a 100 kΩ resistor (R4) on TOFF pin.

In order to use the DIS/SYNC pin functionality, the user has to remove the zero ohm

resistor R9: the PCB already provides a npn transistor connected to this pin for

remote ON/OFF.

The board includes the SR MOSFET (TO220FP package) and can be easily

implemented into an existing converter to substitute rectifier diodes.

Product status link

EVLSRK1001-TO

SRK1001 adaptive synchronous rectification controller for flyback converter

demonstration board with SR MOSFET

EVLSRK1001-TO

Data brief

DB3956 - Rev 1 - October 2019

For further information contact your local STMicroelectronics sales office.

www.st.com