Hello! I'm trying to design and implement an active pfc for a power supply.
Here is the circuit i've made based on the FAN9611's evaluation board.
I've been using the FAN9611 documentation to verify the signals of every pin and I can't figure out why won't it work.
The drive signal is a square wave with holes, in other words, the ic starts to create a pwm drive signal and the it stops and starts again all the time. I'ts not a constant pwm signal as it should be with 40W load (specally when considering the point below)
The circuit its calculated to have a 400V output, but it barely has 10 volts over the rectification voltage (170) (from 120v rectified).
The voltage on the feedback pin is correct, its a portion of the output voltage. In the datasheet says that the feedback voltage should be 3v, but its only 1.9V. I assume then that the feedback is correct but the IC is not being able to rise the output voltage until the FB voltage is 3v
The drive signal is something like this:
Where each line is a burst of PWM (about 15-20 cycles)
I know I'm being very vague with this explanation, but I'll happily provide you with all the information you request
Thank you for your time!
Edits:
The IC is powered from a 12v switching power supply in the same board
Here is the circuit i've made based on the FAN9611's evaluation board.
I've been using the FAN9611 documentation to verify the signals of every pin and I can't figure out why won't it work.
The drive signal is a square wave with holes, in other words, the ic starts to create a pwm drive signal and the it stops and starts again all the time. I'ts not a constant pwm signal as it should be with 40W load (specally when considering the point below)
The circuit its calculated to have a 400V output, but it barely has 10 volts over the rectification voltage (170) (from 120v rectified).
The voltage on the feedback pin is correct, its a portion of the output voltage. In the datasheet says that the feedback voltage should be 3v, but its only 1.9V. I assume then that the feedback is correct but the IC is not being able to rise the output voltage until the FB voltage is 3v
The drive signal is something like this:
Where each line is a burst of PWM (about 15-20 cycles)
I know I'm being very vague with this explanation, but I'll happily provide you with all the information you request
Thank you for your time!
Edits:
The IC is powered from a 12v switching power supply in the same board
Last edited: