SF1539 Balance TM PWM Power Switch Fixed 50kHz Fsw IC Sifirst

• shape: DIP
• Conductive Type: Unipolar Integrated Circuit
• Integration: LSI
• Technics: Thin Film IC
• Application: Standard Generalized Integrated Circuit
• Type: Digital / Analog IC
• Model NO.: SF1539
• Feature: Low Standby
• Trademark: Sifirst
• Origin: China
• HS Code: 8542399000
• Production Capacity: 10000000

Product Description

Datasheet

General Description 
 

SF1539 is a high performance, high efficiency, highly integrated current  mode  PWM   power   switch   for offline flyback converter applications. 
In SF1539, PWM switching frequency with shuffling is fixed to 50KHz 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.
SF1539 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.
SF1539 is available in DIP8 packages.
 

Features

   Built-in 600V Power MOSFET 
   Proprietary η  -BalanceTM  Control  to Boost Light Load Efficiency
   Proprietary  "Zero  OCP/OPP  Recovery Gap Contro
   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

Package/Order Information 





Typical Circuit







Why choose us?

* Specilaze in IC for around 14 years 
* 100% Tested before sale
* Cooperate with over 35 famous brands from domestic and international market
* Competitive and reasonable price 
* Abundant inventory and short lead time
* 24hrs supports from our sales and R&D team
 

Warranty	1 Year
Lead time	3-7 Days

Notes

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