Part Number:BQ4050
Hello
I have designed my own PCB based on the application in datasheet (4s1p --> 14.4V). The DSG and CHG FETs are changed to PSMN1R7-30YL.
Fuse is not used --> FUSE-Pin ist connected to Vss.
The FET-EN is set to HIGH.
Charging works properly but discharging dosn't work.
In charging mode the CHG-Pin is about 25V and this FET is ON. --> OK!
But in discharging mode: The DSG-output ist about 0 to 1.5V.
Another strange value is the PACK-voltage. This is only 4.6V insead of 15V battery voltage. At the resistor R12: PACK+ = 15V and chip-PACK-pin (pin 27) is only 4.6V?????
In this Screen shot the charging mode is shown:
The same in charging mode: The DSG-FET is not switched ON!?!?!? The charging current flows only via the body diode of this FET --> high power dissipation!
I work on this for hours :-(
Can anyone help?
Thanks...