Other Parts Discussed in Thread: BQ76942
What are key things to be aware of for OTP programming for the BQ769x2 devices?
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
The BQ769x2 device family has OTP memory which can be used to modify the device default settings. This can be useful to configure important device settings on the production line.
When should OTP be used?
For many applications, OTP programming is not needed. The device registers can be written by the host microcontroller during startup. This method is used in the Microcontroller code examples and shown in the microcontroller programming video. However, there are some cases where production OTP programming might be needed:
What are the hardware requirements to program OTP?
In order to program OTP, 10-12 V must be applied to the BAT pin and the highest VCx pin (i.e. VC16 for the BQ76952, VC10 for the BQ76942). Otherwise the device will not allow OTP programming. This means that the battery cells should not be connected when programming the OTP.
What are the software steps that should be used to program the OTP?
The software steps are listed in Section 3 of the BQ769x2 Calibration and OTP Programming Guide. This document also describes limitations for how many times the OTP can be written.
I am using the SUV Permanent Fail in my system along with a fuse. How do I prevent my fuse from being blown after I program the OTP using the low 10-12 V supply?
The best way to work around any Permanent Failures that may be triggered during OTP programming is to modify the RAM register after the OTP_WRITE() command before exiting CONFIG_UPDATE mode. More detailed steps are outlined in this thread.