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.
大大通精彩博文 如何以SRK1001設計反激式轉換器?二次側同步整流開發板EVLSRK1001詳細介紹
• Synchronous rectifier for flyback converter, with fixed turn-on and adaptive turnoff • Vcc range: 3.5 V to 32 V • DVS sensing voltage: 185V AMR • Max frequency: 500 kHz • Internal gate drive for N-channel MOSFET • SR MOSFET type: FDPF190N15A (150 V – 19 mΩ) TO220FP
Fig1, PCB Fig 2 Schematics
https://www.st.com/content/st_com/zh/products/evaluation-tools/solution-evaluation-tools/psu-and-converter-solution-eval-boards/evlsrk1001-to.html
