Other Parts Discussed in Thread: , BQ25896, BQ24296
Hello,
I have a problem with the BQ24295, in the case on the EVM (BQ24295EVM-549). It occurs in the following situation (sequence):
We use power from VSYS (~4V) and PMID (5V, from vbus/adapter or boosted). When the Li-battery activates its safety (undervoltage-off), with no VBUS or adapter present (=all power drained) , the bq24295 loses power. The battery may stay off, as if there were no battery, or it may be defective (really no battery).
When VBUS (5V) is applied again,the bq24295 normally supplies PMID and VSYS (w/ 'In regulation"-flag).
If PMID has a load (in my case 50ohm resistive or lower, 100mA+) on startup, the BQ does not supply VSYS (0.00V, with 'In regulation"-flag active). It will also never try to precharge the battery, probably because there is no VSYS. The BQ starts with default registers, since it was a cold start. The status register flags are all normal. Changing any of the register-contents does not activate VSYS. Changing/toggling the /CE or OTG pins does not activate VSYS. Dead as a duck.
1/ Why is there no VSYS in above case ?
I would like to use BQ25896 instead because the voltages and currents can be monitored by the host, but if it exhibits the same problem it is unsuited.
2/ Can I expect the same problem with the BQ25896 ?
Regards,
Michiel