Hi all,
We are having a problem with BQ24010 and TS detection. We have several production batches manufactured in different assembly houses with the same problem.
This is the schematic I'm using. Top is the outer hierarchical level, bottom is the inner hierarchical level. C48 (1uF between Iset and BAT pins) is not populated, as there is an output capacitor between BAT and GND.
The problem is the following:
- After manufacturing, all units passed the tests, including battery charge.
- The units are sent to the customer, some of them are installed, and I guess others are sent to their warehouse.
- After some (variable) time, some units stop charging.
- Analyzing why they are not charging, I found a low impedance (variable, from a few ohms to 40-50 ohms) from TS pin to ground. Changing R1 and R2 had no effect.
- Cleaning the defective board had no effect.
- If we remove BQ24010 and then solder it again (the same chip, not a new one) on the board, it works ok.
It looks like a soldering problem, but this problem happened in several batches manufactured at different assembly houses. It's very suspicious that both assembly houses had the same problem.
Any suggestion?
Thanks in advance,
Carlos