PWM STEP UP DC-DC
CONTROLLER
DESCRIPTION
The UC3380 is PWM step up DC-DC switching controller that
operates from 0.9V. The low start up input voltage makes
UC3380 specially designed for powering portable equipment from
one or two cells battery packs. This device consist of a soft start
circuit, a reference voltage source, an error amplifier, an
oscillator, a phase compensation, a PWM controller and an
output drive circuit for driving external power transistor.
Additionally, a chip enable feature is provided to power down
the converter for extended battery life. The device features a
voltage mode PWM control loop, providing stable and high
efficiency operation over a broad load current range.
FEATURES
* 0.9V low start-up Input voltage at 1mA load
* Low operation current
* 0.5uA low shutdown current
* Fix frequency PWM at 100KHZ
* Built in PWM switching control circuit ,duty ratio is 0~83%
* Output voltage:0.1V step setting is available between 2.0V and
6.5V
* Soft start time: 6ms
* Shutdown function
APPLICATIONS
*Portable devices
*Electronic games
*Portable audio (MP3)
*Personal digital assistant (PDA)
*Digital still cameras(DSC)
*Camcorders
*White LED driver
*Single and dual-cell battery operated products