I'm using the UC2825a for a voltage-controlled halfbridge converter. I need help for the isolated feedback. Because of the 1.25-V-Ramp-offset and the comparator-offset, the output of the integrated Error-amp must be at least 2.3 to 2.5 V. The ramp-voltage is 2 V peak-to-peak. So the output of the Error-amp must be between 2.3 and 4.5. I would like to use a TL431 as the amplifier with compensation network on the secondary side and an optocoupler for the isolation. I have no idea for the schematic between the integrated error-amp and the optocoupler output.