Hi,
I have designed Multi-output flyback power supply by using UCC2813-1 PWM IC,
Input and output specifications are as follows
Vinput- 16V-40V
Vout-5V@5A,+15V@0.75A,-15V@0.75A
Switching frequency -200kHz
The converter is working fine in no load and full load condition as per design specification ,when 5 V output is not loaded the 15 V &-15 V output voltage drops to 8.5 V since the control loop is sensing the feedback voltage from +5 V output.if +5 V output loaded to 3 A the output of +15 V &-15 V are as per specification .
How to regulate the 15 V &-15 V output without loading +5 V output (or at least loading +5 V output lightly)