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 > Step Down Switching Regulators
UC3655 Datasheet

500mA SYNCHRONOUS STEP-DOWN DC/DC CONVERTERS


DESCRIPTION
 
The UTC UC3655 is a synchronous-rectification type DC/DC
converters with a built-in 0.6Ω P-channel driver transistor and 0.7Ω
N-channel switching transistor, which designed to allow the use of ceramic
capacitors. Using only a coil and two capacitors connected externally, the
UC3655 enable a high efficiency, stable power supply with an output
current of 500mA to be configured. Its operating voltage is 2.0V and the
output voltage is programmable in a range from 0.9V to 4.0V in
increments of 0.1V (accuracy: ±2.0%) internally. The oscillation frequency is 1.2MHz.
For operation mode, it is PWM control in the UTC UC3655, the UTC
UC3655 series is automatic PWM/PFM switching control, allowing fast
response, low ripple and high efficiency over the full range of load.
Internal soft start and current control functions are built in it. All
circuits are shutdown to reduce current consumption to as low as 1.0μA or
less during standby mode. With the built-in Under Voltage Lock Out
(U.V.L.O.) function, when input voltage becomes 1.4V or lower the internal
P channel driver transistor is forced OFF.
 



 
FEATURES
 
* Very High Efficiency 92%
* Low Ripple Rejection Voltage 10mV
* Output Current 500mA @VIN=3.0V, VOUT=1.8V
* Oscillation Frequency is 1.2MHz
* With PWM / PFM Automatic Switching Control  
* Maximum Duty Ratio is 100%
* Ceramic Capacitor Available


 
TYPICAL APPLICATION CIRCUIT

About us  |  Products  |  Contact us
Copyright 2011 UTC All received