Other Parts Discussed in Thread: TL431
Hi,
Now, we have met transient issue on 3.3V output project. Attached is the schematic of this system. The input voltage is 18V~75V, the output voltage is 3.3V, the full load is 2.12A. The peak to peak voltage of output is almost 3.5V when the load changes from no load to full load. This lead to the output voltage drop to zero which couldn’t be accepted by customer. Below shows what we have done for this system.
- change TL431 current, voltage drop still exist
- change the output capacitor to 10nf-100nf, couldn’t start up
- change the RC (R12, C12 on schematic) value on comp pin, increase R12 up to 3.5k, the voltage drop is gone but system becomes unstable.
Could you give any suggestions to solve this issue?
Thank you very much.