• Less than 100mW Standby Power
  • Audio noise free operation
  • Proprietary "η-BalanceTM" to boost light load efficiency
  • Proprietary "zero OCP/OPP recovery gap" control
  • Built-in soft start function and Pins Floating Protection
  • Proprietary "Audio Noise Free OCP Compensation"
  • Fixed 65KHz Switching Frequency
  • Frequency Reduction and Burst Mode Control for Energy Saving
  • Built-in synchronous slope compensation
  • Current Mode Control and Cycle-by-Cycle Current Limiting
  • Built-in Frequency Shuffling
  • Built-in Leading Edge Blanking (LEB)
  • Constant Power Limiting
  • Latch Plug-off Protchion
  • 运用

    Offline AC/DC Flyback Converter for
  • AC/DC Adaptors
  • Open-frame SMPS
  • Set-Top Box Power Supplies
  • ATX Standby Power
      • SF5545 is a high performance, high efficiency, low cost, highly integrated current mode PWM controller for offline flyback converter applications. 
        PWM switching frequency with shuffling is externally programmable, which can reduce conduction EMI emission of a power supply. When the output power demands decrease, the IC automatically decreases switching frequency based on the proprietary η-BalanceTM control to boost Power conversion efficiency at the light load. When the current set-point falls below a given value, e.g. the output power demand diminishes, the IC enters into burst mode and provides excellent efficiency without audio noise.
        SF5545 can achieve "Zero OCP/OPP Recovery Gap" using SiFirst's proprietary control algorithm. SF5545 also has built in proprietary "Audio Noise Free OCP Compensation",which can achieve constant power limiting and can achieve audio niose operation at heavy loading when line input is around 90VAC .  
        SF5545 integrates functions and protections of Under Voltage Lockout (UVLO), VCC Over Voltage Protection (OVP), Cycle-by-cycle Current Limiting (OCP), All Pins Floating Protection, Over Load Protection (OLP), RT Pin Short-to-GND Protection, Gate Clamping, VCC Clamping, Leading Edge Blanking (LEB). 
        SF5545 is available in SOT23-6, DIP-8 packages.