I set the charge current by :
I2C_Write_Register(0x02, 0x00);
I2C_Write_Register(0x03, 0x01);
which set a 256mA current.
However, I monitor a 1024mA charge current.
Why?
Thanks for your help!
Original question:
Some further measurement is performed.
I set the charge current to be 256mA.
Then I measure the charge current to the barrery is 256mA indeed. ( My battery is 13V now. )
However, I find that the input current ( output current of my 12V adapter) is 1.5A.
If I unplug the battery, let the bq25703a circuit to power my system, the input current will be 0.3A.
which mean that charge a (13V) 256mA current will consume (12V) 1A input current.
The following image is my PCB layout. Gate path is highlighted.
It looks to me a board or design issue. To quick find the cause, my suggestion is to order a BQ25703AEVM and check the EVM performance.
Maybe you can try to add 150pF gate capacitor on the bottom FETs in the meanwhile.
