HIGH PERFORMANCE POWER FACTOR CORRECTION CONTROLLER IN CONTINUOUS
CONDUCTION MODE
DESCRIPTION
The UTC L8565 is a wide input range controller integrated circuit for
active power factor correction. The circuit is designed for boost PFC
application, and requires reduced external component count. Its power
supply is recommended to be provided by an external auxiliary supply
which will switch on and off the IC.
The circuit operates in the continuous conduction mode under average
current, and in discontinuous conduction mode only in light load
condition. The switching frequency can be set with the external resistor at
pin 4. Both current and voltage loop compensations are done externally
to allow full user control.
There are many kinds of protection features incorporated to make sure of safe system operation conditions, such
as brown-out protection, output under voltage detection and peak current limitation. The insi de reference is adjusted
(5V±2%) to make sure control level and precise protection. T here is a particular soft-start function to limit the start up
current and thus reduces the stress on the boost diode.
FEATURES
* Supports wide input range
* Average current control
* Ease of use with few external components
* External current and voltage loop compensation
* Trimmed internal reference voltage (5V±2%)
* Programmable operating/switching frequency (50kHz ~ 250kHz)
* Max duty cycle of 95% (typ) at 125kHz
* Under voltage lockout
* Cycle by cycle peak current limiting
* Over-voltage protection
* Open loop detection
* Output under-voltage detection
* Brown-out protection
* Soft Over current Protection
* Enhanced dynamic response |
