SLUAAF8 October 2021 BQ24707 , BQ24707A , BQ24725A , BQ24735 , BQ24770 , BQ24780S , BQ24800 , BQ25700A , BQ25708 , BQ25710 , BQ25720 , BQ25730 , BQ28Z610-R1 , BQ4050 , BQ40Z50 , BQ40Z50-R1 , BQ40Z50-R2 , BQ40Z80
Using the register bit definitions outlined in the data sheet of the charger, the charge current and voltage writes can be verified using a logic analyzer or oscilloscope. For the BQ40Z50 and other SMBus devices, the communications in broadcast mode can be PEC enabled with the SBS configuration[CPE] bit. SBS configuration[HPE] does not affect this system because there is no host. If both SBS configuration[HPE] and SBS configuration[CPE] are disabled the gauge will not transmit a PEC byte during any communication. The current and voltage are transmitted from the gauge in little endian, so the format of transmission is the following when the SBS configuration[CPE] bit is set:
Charger address (write) -> Register to write -> Least significant byte -> Most significant byte -> PEC Byte.
For the I2C-based system the package structure is the same, except the Packet Error Checking (PEC) byte is not used for I2C-based systems so there are no PEC enable options for the BQ28Z610-R1.