SiFirst Technology SF1533
SF1533 is a high performance, high efficiency, highly integrated current mode PWM power switch for offline flyback converter applications. When the output power demands decrease, the IC decreases switching frequency based on the proprietary η -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.| Part No. | SF1533 |
|---|---|
| Datasheet | SF1533 Download |
| Manufacturer | SiFirst Technology |
| Description | PWM Power Switch |
| Buy | Stock & Price |
FEATURES
● Built-in 600V Power MOSFET● Proprietary η-BalanceTM Control to Boost Light Load Efficiency
● Proprietary “Zero OCP/OPP Recovery Gap” Control
● Fixed 50KHz 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)
APPLICATIONS
Offline AC/DC Flyback Converter for● AC/DC Adaptors
● Open-frame SMPS
● Set-Top Box Power Supplies
● ATX Standby Power
GENERAL DESCRIPTION
In SF1533, PWM switching frequency with shuffling is fixed to 50KHz and is trimmed to tight range. 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.
