Other Parts Discussed in Thread: TPS25750, BQ25792,
Tool/software:
I have made a design with TPS25750 and BQ25792 for charging a battery and powering the device.
And i have this working with out problems.
setup is for 1S lipo battery.
Due to the bug fixes in that are implemented in the new part TPS25751 i have now installed this part in place of the TPS25750.
i kept the cat24C256 eeprom because the eeprom that is generated is 28.1KB so that fits in the eeprom and its the full binary that i have generated.
But i am unable to get this to work like the old setup.
I have a led on the BQ25792 stat pin and that is blinking red.
I have installed the new USBCPD Application Customization Tool Version: 0.6.0
To generate the new binary file for the TPS25751 with the same settings i used for the old TPS25750 (TPS25750 application customization tool V: 7.0.4.7) i had working.
After checking with a logic analyzer on the I2C bus i came to the conclusion that the initializing of the BQ25792 is going different.
it starts with a read of 0x01 that returns 0x01
then it writes 0x00 to 0x010 and does this 2x
then it write 0x1C to 0x14
then it write 0x00 to 0x11
then it write 0x80 to 0x12
then it write 0x01 to 0x08
then it write 0x01 to 0x09
then it write 0x01A4 to 0x01
then it write 0x012C to 0x03
then it write 0x00 to 0x0F
then it write 0x80 to 0x12.
then it write 0x00 to 0x0F
then it write 0x00 to 0x0B
then it write 0x00 to 0x06
then it write 0x00 to 0x03
if i compare this to the old TPS25750 initial of the BQ25792
write 0x80 to 0x10
then it write 0x1C to 0x14
then it write 0x00 to 0x11
then it write 0x00 to 0x12
then it write 0x01 to 0x08
then it write 0x01 to 0x09
then it write 0x01A4 to 0x01
then it write 0x012C to 0x03
I see that the TPS25751 is going wrong on register 0x10 and 0x12.
Register 0x10 reset is 0x85 with bits 7 and 6 reserved. so if a 0 is send to this register it should be sending a 0x80 and not a 0x00.
with register 0x12 sending 0x80 it forces EN_ACDRV1=0 and EN_ACDRV2=0. but it should not need to do this. because the TPS25750 send 0x00 and that was working.
or am i missing something ?