We have employed the TPS56428 for converting 7.4v to 5 v and 7.4v to 3.8v, with the circuit shown below, but the circuit worls for some days, and all of a sudden the TPS56428 gets short circuited( the device gets damaged), could you resolve the problem facing, thanks in advance
Thanks for the reply
, we have checked with the input source, it seems to have some instability, it goes upto 20v sometimes for a small duration.
We are attaching the layout for your reference. The IC1 and IC2 are TPS56428DDA
The root cause is that vin goes too high, causing damage.
Besides, the layout is bad. Please read chapter 11 in datasheet to get the general layout tips.
Specifically, in your layout for IC1,
1. C1 and C2 GND connection to IC GND Pin is too long. It is not good to use via connection, this loop must have least parasitic inductance as possible.
2. don't use wire to connect sw to inductor.
3. the c5,c6,c21 connection to Vout and GND, is too thin. use wide copper.
4. place R4 close to IC
5. place c3 close to IC
Here is another apps note for you to get more knowledge about the layout tips for Buck converter:
