η -BalanceTM  PWM Power Switch  Fixed 65KHz Fsw and OTP Protection

Product：SFL1539HT

一、General Description

SF1539HT  is  a  high  performance,   high  efficiency, highly integrated current mode PWM power switch for offline flyback converter applications. 
 In  SF1539HT,  PWM    switching    frequency   with shuffling  is  fixed  to  65KHz  and  is  trimmed  to  tight range.  When  the  output  power  demands  decrease, he  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. 

SF1539HT  integrates  functions   and  protections  of Under  Voltage  Lockout  (UVLO),  Over  Temperature Protection   (OTP), 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.SF1539HT is available in DIP8 packages. 

二、 Features

  Built-in 600V Power MOSFET 
  Over Temperature Protection (OTP)
  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)

三、Applications

Offline AC/DC Flyback Converter for

  AC/DC Adaptors 
  Open-frame SMPS
  Set-Top Box Power Supplies 
  ATX Standby Power 
 

四、Package/Order Information

五、Typical Application

FREE HOT LINE:+86-400-788-7770

Tel:+86-769-81150556　　　 Mob:+86-18929103949 Ms Tang
Tel: +86-769-85638990　　　Mob:+86-18923224605  Ms Ye
Email: dgzm699@163.com      QQ:2485843216

Fax:+86-769-83351643

 

Head office:  No.8, Yanhe East Street, Ailingkan Village, Dalingshan Town,  Dongguan City, Guangdong Province, China

Foshan office: No.169 Rongqi Road,Ronggui Village,Shunde District,Foshan City,Guangdong Province,China

Shenzhen office:Baifuhui Industrial Park,Jianshedonglu Road,Longhua District,Shenzhen City,Guangdong Province,China

Zhongshan office:Shijihaoting,Longchang Road,Dongsheng Village,Zhongshan City,Guangdong Province,China

Hangzhou office:Jiangnanmoka,Wenyan Village,Xiaoshan District,Hangzhou City,Zhejiang Province,China

 

Office Website: www.topctc.com