Press Center
 
Home About us Products Support Quality & Certification Career Contact us
• Power Management
    Linear Regulators
    Low Dropout Linear Regulators
    DDR Termination Regulators
    Shunt Reference Regulators
    Step Down Switching Regulators
    Switching Regulator
    Step-Up DC-DC Converter
    PWM Controller
    White LED Driver
    Supervisory Circuit
    Voltage Detection and System R
    USB Power Switch
    Power Factor Control
    Li-Battery Protection or Charg
    FET Bias Controllers
    Combo IC
    Inverting DC-DC Converter
• Amplifier / Comparator
    Audio Amplifiers
    Operational Amplifier
    Voltage Comparator
• Analog Switches
    Video Signal Switch
    Analog Multiplexers, Demultipl
• Hall ICs
• Special Application ICs
    Motor Controller IC
    Interface and Driver Circuit
    Telecommunication Circuit
    Melody IC
    Alarm /Sound Generator IC
    Remote Controller IC
    Television Circuit
    Leakage Current Detector
    Automotive IC
    A-D or D-A Converters
    Miscellaneous
    Radio and Cassette Recorder Ci
    Timer
    Mouse&Keyboard Controller
    Transient Voltage Suppressors
    Sense Monitor
    Video Filter
    ZCB snubber
• Logic
• TRANSISTORs
• MOSFETs
    JFET
    Power Mosfet
• TRIACs
• SCRs
• DIODEs
 
Home > PWM Controller
UC3869 Datasheet

HIGH VOLTAGE GREEN MODE PWM CONTROLLER
 

 
 
DESCRIPTION
 
The UTC UC3869 is a highly integrated current mode PWM
control IC with high voltage start up, optimized for high
performance, low standby power consumption and cost effective
offline flyback converter applications. 
PWM switching frequency at normal operation is internally fixed
and is trimmed to a tight range.   At no load condition, the IC
operates in power-saving mode for lower standby power,
decreasing frequency for Higher conversion efficiency at light load
condition. The internal slope compensation improves system
stability at high PWM duty cycle output. Leading-edge blanking on
current sense input removes the signal glitch, which offering
minimal external component count in the design. 
The UTC UC3869 offers complete protection coverage
including Cycle-by-Cycle current limiting (OCP), V
under voltage
DD
lockout (UVLO), over load protection (OLP), over temperature
protection (OTP), and over voltage protection (OVP). Excellent EMI
performance is achieved with UTC proprietary frequency hopping
technique (ZL201020615247.1) together with soft driver control.
Audio noise is eliminated due to switch frequency more than 20kHz
during operation. The tone energy at below 22KHZ is minimized to
avoid audio noise during operation.
 


 
FEATURES
 
* High voltage startup  
* Power on soft start reducing MOSFET Vds stress  
* Efficiency and minimum standby power
* Frequency shuffling for EMI  
* Audio noise free operation
* Fixed 65KHZ switching frequency
* Comprehensive protection coverage
 V DD  Under Voltage Lockout with Hysteresis (UVLO)  
Cycle-by-cycle over current protection (OCP)
 Overload Protection (OLP) 
 External programmable Over Temperature Protection (OTP)
 V DD  Over voltage Protection(OVP) 
About us  |  Products  |  Contact us
Copyright 2011 UTC All received