Other Parts Discussed in Thread: BQ25756,
Tool/software:
Hello
have designed a charger for 1 LiPo with TPS25751 and BQ25756.
It is based on the example -> 100W USB Type C Charger
But modified to work with a microcontroller in place of I2C memory.
The boot works fine, I load the config and the devices go into APP mode.
PPHV = 5V (tested with a 5V USB-C charger).
After that, I see that it transfers data on I2C and the BQ25756 replies, but the first transaction is a read the register 0x33 and the BQ25756 replies with 0x00 0x00.
If I read the BQ25756 datasheet, it says REG0x33_VBAT_ADC, So I understand that the BQ25756 shows the battery with 0V, but I have 3.3V on the battery. Is this normal or not?
Where is VBAT measured?
Can you help me?
The full I2Cm transaction
read 0x33 reply 0x00 0x00
write 0x19 0x00
write 0x19 0x00
write 0x17 0xCC
write 0x19 0x0D
write 0x0A 0x4C 0x00
write 0x02 0x00 0x00
write 0x06 0x20 0x00
write 0x08 0x48 0x03
The shematic
the config
