Other Parts Discussed in Thread: STRIKE
Tool/software:
We have contacted Uwe Haensel, EMEIA Field Quality Engineer, Texas Instruments about the failure of BQ76940 component in our board. He suggested to forward the case to E2E.
Based on your Quality analysis report provided by Uwe, please consider the below points:
- Confirm that part was working initially: The part was initially passed with all test points using test jig.
- EOS / EIPD (Electrical Induced Physical defect) due to an overstress/out of spec condition:
- Maximum cell voltage(VCn–VCn–1) = 4.2V(each cell)
- Over all voltage (cell 1 to cell 14) ≈ 58V
- Maximum temperature - 40 °C
- AMR (Absolute Maximum Rating): In our design, we follow the below mentioned values according to the specifications in the datasheet (attached the interface image where Cell 6 voltage is read as zero).
|
Description |
Spec in datasheet |
Our design |
|
Input voltage: (VCn–VC10x) where n = 11..15 |
(n–10) × 7.2 |
VC11–VC10x = 3.6V (min), 4.2V (max) |
|
Cell input voltage, differential (VCn–VCn–1) where n = 1..15 |
-0.3V to 9V |
Minimum cell voltage: 3.6V Maximum cell voltage: 4.2V |
- Also, we confirm that design was not changed past four years.
Therefore, we request a meeting to discuss in detail on the possible causes and other parameters leading to the failures, while we simultaneously send the failed samples.
