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BQ76952EVM: Data read back does not match settings

Part Number: BQ76952EVM

As can be seen in the bottom line below, PF_EN is True and FET_EN is False. I verified that Settings:Manufacturing:Mfg. Status Init was 0x0010 so both of these bits are wrong. I even wrote that byte again with no effect.

I am using version 1.3.124 Build 1 with the EVM.

Any idea why I cannot get the FETs on in SLEEP mode?

Deepcore Battery

  • Hi Steven, 

    A have a few follow up questions: 

    On the following, a status of Settings:Manufacturing:Mfg = 0x10 indicates the device is configured in "FET Test Mode", so is controlled only by FET Test Subcommands or using the CFETOFF/DFETOFF pins.  

    Settings:Manufacturing:Mfg. Status Init was 0x0010

    How are you trying to enable the FETs? 

    Also, 0x0010 does not matched the screen shot above or the gg.csv file. When you say even when you write that byte again has not effect, what byte are you referring to? And is the device NACKing? 

    Also, have you been able to properly follow the Quick Start instructions of the EVM User Guide Section 2.2, this should make sure everything on the EVM is configured properly for FETs to be enabled. 


    Arelis G. Guerrero 

  • My documentation of Settings:Manufacturing:Mfg = 0x10 indicates the device is configured to ignore Test commands. Is this incorrect?

    4     FET_EN 0       This bit enables or disables FET Test mode. In FET Test mode, the FET states are controlled by the FET Test subcommands. This is typically used during
    manufacturing to test FET circuitry. Note that safety checks still may force FETs off (or for body diode protection, on) in FET Test mode.
    0 = Normal FET control is disabled. FET Test mode is enabled. Device will not turn on FETs unless FET Test subcommands instruct it to do so.
    1 = Normal FET control is enabled. FET Test mode is disabled. Device will ignore FET Test subcommands.

  • My problem was that the Eval board stopped communicating because I had not enabled the two regulators. Those are needed on the Eval board.