TPS40210: Check the TPS40210 fly-back schematics

Hi Henry,

Thank you for designing with the TPS40210. My comments:

• L10=3.3uH appears to be too large there.  You just need maybe 0.33uH or smaller for the second stage filter.
• Add a Electrolytic capacitor in parallel with C123.
• Raise R189 and R216 size to be able to handle the power dissipation.  Neither 0603 nor 0805 are adequate.
• Reserve a parallel diode to R418 in case you need it to speed up the turn off time. 
• Double check if C345 is grounded ( I don't see the joint dot). In layout, C345 ground pin should be close to IC GND pin.
• Make sure your aux winding can create a voltage > the voltage created by Q24.

Thanks,

Youhao Xi, Applications Engineering