Thanks John , This is Follow up related to your earlier response
As per the TPS548D21 datasheet, with the Eval board layout, considering Natural convection, below measured temperature data is reported on Pg 9, Figures 3 and 6:
40A I out, Measured temperature = 86C, Temperature rise at IC = 66C
30A I out, Measured temperature = 75.3C, temperature rise at IC = 48.3C
So we expect that for 25A load current the temperature rise should be lower than 48.3C..
In our case we expect the worst case ambient in the vicinity of the TPS548D21 chip to be around 85C
Can an estimate be provided for the temperature rise at IC for two cases?
- 20A output load current
- 25A output load current.
as unable to open the link View online
Seetaram,
Yes the power density is quite high. At 40 A output current you may see temperature rise of 75 deg. C. At 25 A it should be lower. Even not considering the copper trace, The IC itself, as well as the output put inductor, will contribute to the temperature rise. for 25 A output, I would expect the temperature rise to be about 25 deg. C. less or about 50 deg. C. This is based on measured thermal performance as shown in the datasheet. Let me know if you have further questions.