SF5785
Release time:2022-12-16 10:37:29 Author: 赛威科技 Source:

2nd Generation Quasi-Resonant (QR-IITM ) PWM Switch with Brownout Protection


FEATURES

   Meet EPS Level 6

   AC Brownout Protection (BOP)

   Built-in 650V Power MOSFET

   Proprietary QR-IITM Technology:

●Digital Anti-jitter for Audio Noise Free Operation

● Digital Frequency Foldback

● Digital Frequency Jittering for Better EMI

   Less than 75mW Standby Power

   Multi-Mode Operation for High Efficiency

   12.7us Maximum On Time

   80KHz Maximum Frequency Limit

   52KHz Frequency Low Clamping in QR Mode

   65% Maximum Duty Cycle

   Adaptive Slope Compensation for CCM Mode

   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

GENERAL DESCRIPTION

SF5785 is a high performance, 2nd Generation Quasi-Resonant (QR-IITM) PWM switch for offline flyback power converter applications. The built-in proprietary QR-IITM technology with high level protection features improves the SMPS reliability and performance.

In SF5785, 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.

SF5785 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 75mW no load power.

SF5785 integrates functions and protections of Under Voltage Lockout (UVLO), VCC Over Voltage Protection (OVP), Output Over Voltage Protection (Output OVP), Cycle-by-cycle Current Limiting (OCP), Pin Floating Protection, Over Load Protection (OLP), AC Brownout Protection, Soft Start, VCC Clamping, Gate Clamping, etc. In SF5785, the protection functions are auto-recovery mode protection.

 SF5785 is available in DIP-8 package.


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