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TPS2H000-Q1: External component with 3.3V I/O

Kenneth Lee
Intellectual 1718 points
Part Number: TPS2H000-Q1

Hello,

It has 5V MCU implemenation for TPS2H000 in the datasheet, but needs reference schematic for 3.3V MCU.

What is the recommended value for R(pullup), R(ser) and R(cs) for 3.3V MCU?

Because Vcs(h) can be 4.5~6.5V, it would need voltage divider to connect CS pin to 3.3V ADC input.

Is there're any recommended resistance for the divider?

Iout normal is 250mA and current limit is 0.5A as design requirement.

Thank you in advance.

  • 0
    TI__Expert 3500 points
    Kenneth-

    Rser and RPU should be 10kOhm regardless of supply, so please use those values. For RCS, there is no need for a voltage divider as long as the RCS value is low enough that it will not exceed 3.3V. In this case, if VCS = 3.3V and IOUT = 0.5V max, with KCS of 80 then the RCS value should be 528ohm. (Eq 9 on the datasheet page 28) Note that this assumes that the current will never exceed 0.5A, in reality there is some overshoot during short-crcuit events, so I would use a value like 400ohm.

    Thanks,
    Alec
  • 0 in reply to Alec Forbes
    TI__Intellectual 1718 points

    Hello Alec,

    Thank you very much for your support.

    I understand the Vcs in linear region will be below 3.3V with proper Rcs.

    However, in fault state, Vcs will jump to Vcs(H) which is defined as minimum 4.5V when Vvs>7V from my understanding.

    Is this correct? If yes, isn't there voltage divider needed?


  • 0 in reply to Kenneth Lee
    TI__Expert 3500 points
    You are correct, that is my mistake! With a max ILIM of 6.5V, you will need to have a voltage divider on the pin to lower the MCU voltage to 3.3V. With a 6.5V max, I would recommend using even resistor values on each side.
  • 0 in reply to Alec Forbes
    TI__Intellectual 1718 points
    No problem! Thank you very much.