UC3551数据手册UTC中文资料规格书

描述 Description

The UTC UC3551 is a step-up DC/DC converter with high efficiency and low start-up voltage. It is operaded in stable waveforms without external compensate. This device incorporates an adaptive current mode PWM control loop in which an error amplifier, ramp generator, comparator, switch pass element and driver are included. Besides, this circuit provides a stable and high efficient operation over a wide range of load currents.   The UTC UC3551

特性 Features

high switching rate which is up to 450
·KHz, making the external component counts less required.
·Moreover, it features 17μA low quiescent current, which makes the
·battery life longer. The low start-up input voltage below 1V makes
·UTC UC3551 suitable for 1 to 4 battery cells applications of
·providing up to 300mA output current.  
·Two external resistors determine the value of the output voltage.
·The external power devices (NMOS or NPN) are derived by both
·internal 2A switch and driver.  
·The UTC UC3551 is intended to be used in PDA, DSC, LCD
·Panel, RF-Tags, MP3, portable instrument and wireless equipment.
 
  
FEATURES
 
· Low Start-up Input Voltage is as Low as 1.0V
· Efficiency up to 90%
· High Supply Capability to Deliver 3.3V 100mA with 1 Alkaline Cell
· Quiescent (Switch-off) Supply Current: 17µA
· Zero Shutdown Mode Supply Current
· Fixed Switching Frequency: 450KHz
· Both Internal and External Power Switches for Maximum Flexibility