the ucc28810 and ucc28811 are general lighting power controllers for low to medium power lumens applications requiring power factor correction and emc compliance. it is designed for controlling a flyback buck or boost converter operating in critical conduction mode. it features a transconductance voltage amplifier for feedback error processing a simple current reference generator for generating a current command proportional to the input voltage a current-sense (pwm) comparator pwm logic and a totem-pole driver for driving an external fet. in the critical conduction mode operation the pwm circuit is self-oscillating with the turn-on being governed by a transformer zero energy detector (tze pin) and the turn-off being governed by the current sense comparator. view all in datasheet