发布时间:2022-12-26 08:29:10 作者: 赛威科技 来源:

                                             η-BalanceTM  PWM Power Switch Fixed 65KHz Fsw


   Less than 75mW Standby Power

   Built-in 650V Power MOSFET

   Proprietary η-BalanceTM Control to Boost Light Load Efficiency

   Proprietary “Zero OCP/OPP Recovery Gap” Control

   Fixed 65KHz Switching Frequency

   Built-in Soft Start Function

   Very Low Startup Current

   Frequency Reduction and Burst Mode Control for Energy Saving

   Current Mode Control

   Built-in Frequency Shuffling

   Built-in Synchronous Slope Compensation

   Cycle-by-Cycle Current Limiting

   Built-in Leading Edge Blanking (LEB)

   Constant Power Limiting

   Pins Floating Protection

   Audio Noise Free Operation

   VDD OVP & Clamp

  VDD Under Voltage Lockout (UVLO)



Offline AC/DC Flyback Converter for

   AC/DC Adaptors

   Open-frame SMPS



SF5549H is a high performance, high efficiency, highly integrated current mode PWM power switch for offline flyback converter applications.

In SF5549H, PWM switching frequency with shuffling is fixed to 65KHz and is trimmed to tight range. When the output power demands decrease, the IC decreases switching frequency based on the proprietaryη-BalanceTM control to boost power conversion efficiency at the light load. When output power falls below a given value, the IC enters into burst mode and provides excellent efficiency without audio noise.

The IC can achieve “Zero OCP/OPP Recovery Gap” using SiFirst’s proprietary control algorithm. Meanwhile, the OCP/OPP variation versus universal line input is compensated.

The IC has built-in synchronized slope compensation to prevent sub-harmonic oscillation at high PWM duty output. The IC also has built-in soft start function to soften the stress on the MOSFET during power on period.

SF5549H integrates functions and protections of Under Voltage Lockout (UVLO), VCC Over Voltage Protection (OVP), Cycle-by-cycle Current Limiting (OCP), Pins Floating Protection, Over Load Protection (OLP), VCC Clamping, Leading Edge Blanking (LEB), etc.

SF5549H is available in DIP8 packages.

上一个: SF292X
下一个: SF5569H