Our latest rev of a stable design is showing extreme instability in the supply voltage regulated by the TPS62050. The previous design showed no such instability. The layout is identical in the area of this part, with no significant downstream changes. The new build breaks into a very unstable output at input voltages above 4.2V. The part is spec’d to 10V in. Topmark on the chip on the previous build is 46 TI BFM; those chips work as described in the datasheet. Topmark on the new build is 55 TI BFM. Have there been any other reports of issues with this lot?
Hello stevehx, sorry to hear you are experiencing this issue with the 296-14392-1-ND. I am not seeing anything in our history or on record that talks about this issue with the instability of the output on the TPS62050. If you feel that the product you received is defective, please send this inquiry to techs@digikey.com along with order information and details and we can assist you.
As mentioned, we’ve no indications of others having issues with the product.
Genuine defects are quite rare among material from production-grade suppliers, and the odds of being par-per-million level unlucky on the defect front coincidentally with a new design/design change are basically zero.
Exchanging parts between boards and seeing if the misbehavior follows or not (known as an A-B-A swap) would be something to try, and one may want to look at any BoM changes closely. Ceramic caps can exhibit a rather nasty loss of capacitance under bias, and that could easily explain an instability that appears as bias is increased…