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Hello TI team,
I'm about to use: BQ76942, Communications Interface: I2C, REG1 LDO default: disabled.
Not intend to use internal LDO, REG1 and REG2. Run BQ76942 in fully autonomous mode, no external MCU.
REGIN and BREG connected to VSS.
REG1: floating
REG2: floating.
Calibration and OTP programming will be done by using external equipment. Pull-up for I2C will be on placed in
external equipment. Attach simplified block diagram.
Cells will be assembly after calibration and OTP programming.
Question 1: Is it possible to communicate BQ76942 according to attached block diagram? Guess REG18 is used for internal logic.
Question 2: Once calibration and OTP programming is done, pull-up on SDA and SCL is left floating, is that okay?
Question 2.1: If floating is not okay, how should SDA and SCL be handled since I can't have pull-up to REG1?
Regards,
Andreas
Hello Andreas,
It is perfectly okay to use an external regulator for the pull-ups, you do not need to use REG1/REG2 with our I2C.
Question 1: Is it possible to communicate BQ76942 according to attached block diagram? Guess REG18 is used for internal logic.
Yes, this looks okay to me 
. 3.3-V pull-up should be more than okay. Pull-up resistors may be better to be slightly larger, we use 10-kOhm pull-ups in our EVM.
Question 2: Once calibration and OTP programming is done, pull-up on SDA and SCL is left floating, is that okay?
Yes, that is okay if you are not interfacing with a MCU. Keep in mind that during OTP, the BAT and VC10 voltages need to be ~11-V or so.
Question 2.1: If floating is not okay, how should SDA and SCL be handled since I can't have pull-up to REG1?
See answer above. These can be left floating.
Let me know if there are any additional questions!
Best Regards,
Luis Hernandez Salomon
