发布时间:2022-12-16 10:59:28 作者: 赛威科技 来源:

HV-mWTM2nd Generation Quasi-Resonant (QR-IITM ) PWM Controller

With PFC ON/OFF Control


   Meet EPS Level 6

   Smart PFC Control Function Integrated

   Proprietary QR-IITM Technology:

●Digital Anti-jitter for Audio Noise Free Operation

● Digital Frequency Foldback

● Digital Frequency Jittering

   Proprietary HV-mWTM to Achieve Ultra Low Standby Power

   Multi-Mode Operation for High Efficiency

   12.7us Maximum On Time

   80KHz Maximum Frequency Limit

   53KHz Frequency Low Clamping in QR Mode

   Maximum 65% Duty Cycle

   Adaptive Slope Compensation for CCM Mode

   Latch Plug-off Protection

   Built-in Soft Start Function

   Pin Floating Protection

   Built-in Synchronous Slope Compensation

   Cycle-by-Cycle Current Limiting

   Leading Edge Blanking (LEB)

   Constant Power Limiting

   VDD UVLO, OVP & Clamp



Offline AC/DC Flyback Converter for

   AC/DC Adaptors

   SMPS Power Supply


SF5897 is a high performance, 2nd Generation Quasi-Resonant (QR-IITM) PWM controller for offline flyback power converter applications. The built-in proprietary HV-mWTM technology and QR-IITM technology with high level protection features can improve the SMPS reliability and performance. SF5897 can turn off FPC power supply for higher efficiency at light load.

In SF5897, the “Digital Anti-Jitter” function can automatically select and lock a valley at a given loading, which can achieve audio noise free operation. On the other hand, the “Digital Frequency Jittering” function makes the system have superior EMI performance than conventional QR system.

SF5897 is a multi mode controller. When full loadings, the IC works in CCM mode or QR mode based on the AC line input. When the loading goes low, the IC enters into “Digital Frequency Foldback” mode to boost power conversion efficiency. When the output power is very small, the IC enters into burst mode and can achieve less than ultra low standby power.

SF5897 integrates functions and protections of Under Voltage Lockout (UVLO), VDD Over Voltage Protection (VDD OVP), Output Over Voltage Protection (Output OVP), Cycle-by-cycle Current Limiting (OCP), Pin Floating Protection, Over Load Protection (OLP), Soft Start, VDD Clamping, Gate Clamping, etc. In SF5897, VDD OVP and Output OVP are latch mode protections, the other protections are auto-recovery mode.

SF5897 is available in SOP8 package.

上一个: SF4711
下一个: SF5877