PWM STEP-DOWN DC-DC CONTROLLER
DESCRIPTION
The UTC UC4601 is a PWM step-down DC/DC controller. It has
a low supply current. The step-down DC/DC converter with low
ripple, high efficiency performance is conveniently configured with
additional external components, such as a power-transistor, an
inductor, a diode and capacitors. The output voltage can be adjusted
with external components.
The UTC UC4601 contains a high precision band-gap voltage
reference, a PWM control circuit, a soft-start circuit, a protection
circuit, an oscillator, an error amplifier with built-in compensation
network and input/output voltage detection circuits.
The UTC UC4601 based DC/DC converter can performance well
when maintaining stability, which is due to its built-in state-of-art
control algorithm. Further, if the term of maximum duty cycle retains
on a certain time, the embedded protection circuits restart the
operation with soft-start and repeat until the maximum duty cycle
condition is released. Finally, the internal UVLO function blocks
potentially unstable output when the input voltage reaches the UVLO
threshold or less. This is aiming at making this circuit standby for low
power consumption.
The UTC UC4601 can be applied in battery-powered equipment,
hand-held communication equipment, cameras, video instruments
such as VCRs, camcorders, household electrical appliances.
FEATURES
* 500kHZ oscillation frequency
* Input voltage varies from 2.3V to 18V
* Low temperature coefficient of output voltage: Typ. ±100ppm/°C
* Internal soft-start and protection function
* High efficiency up to 90% (TYP.)
* High output voltage accuracy: ±2%
* Standly current: 0.1μA (TYP.)
* CMOS output capability |
