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.

TCA9543A: Can it still work normally when VDPUx<VCC*0.7(VIH)?

Part Number: TCA9543A

Can it still work normally when VDPUx<VCC*0.7(VIH)?

  • Yes. The TCA9543A's control logic can be accessed only from the SDA/SCL pins. The other SDx/SCx pins are analog switches and can use any pull-up voltage (that is not too far below VCC).

  • Hi Clemens,

    Can it be understood that VDPUm cannot be lower than VCC*0.7 and VDPU0/1 is not limited by VCC?

    Thank you!

  • VDPUM must be higher than 70% of VCC to allow the master to control the channels. All VDPUM and VDPUx are limited by the maximum pass-through voltage of the pass-gate transistors (see section 9.2.1 and figure 17).

  • Hi Jian,

    The figure that Clemens is referencing is the pass gate voltage spec vs. VCC graph.

    Vpass is defined as the smallest pull-up voltage (VDPUM or VDPUx) in the system. Based off this pull-up voltage, the user can determine what is the highest VCC can be used in the system to ensure correct voltage translation. 

    Also from the recommended operating specs.

    1.65V < VCC < 5.5V 

    1.65V < VDPUx < 5.5V 

    1.65V < VDPUM < 5.5V