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TPS65987D: Dead battery operation of TPS65987D

user6553255
Prodigy 40 points
Part Number: TPS65987D

Hi, team,

Let me check the Dead battery operation of TPS65987D.

In the hardware I am designing, SPI Flash (FW and initial settings) is connected to TPS65987D, and control is performed from the microcomputer connected via I2C1.
Also, I am thinking of setting "BP_NoResponse, Safe" in the hard strap setting of ADCIN1.
At this time, when VIN_3V3 is 0V, if the connection partner has Source capability, VBUS is output from the other party and 3.3V is output to LDO_3V3.

(Q1) If LDO_3V3 is started by VBUS when VIN_3V3 is 0V and then VIN_3V3 becomes 3.3V, what is the timing when FW and settings are read from SPI Flash?
    From the description in "Table 6" of "SLVSES1B", I think that reading starts after VIN_3V3 becomes 3.3V. Is this correct?

(Q2) Is it possible to control by communicating with TPS65987D with I2C1 after VIN_3V3 becomes 3.3V?

(Q3) Isn't it possible to see the voltage from the VBUS terminal to PP_HV1 and PP_HV2 before instructing the VBUS terminal and PP_HV terminal to turn on the switch by I2C1 control?

Best regards,

Hamada

  • +1
    TI__Mastermind 30000 points

    Hello,

    Find answers to your questions below:

    Q1: Yes, that is correct. If you put the TPS65987D in "BP_NoResponse, Safe" state, then the TPS65987D will not try to load the configuration from the external EEPROM until after VIN_3V3 is available.

    Q2: Yes, you can communicate to I2C1 after 3.3V has been applied to VIN_3V3

    Q3: If you configure the TPS65987D to "BP_NoResponse, Safe", it will automatically close the power paths in a dead battery condition