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TCAN1042V-Q1: TXD pullup voltage 2.7V

Part Number: TCAN1042V-Q1
Other Parts Discussed in Thread: TCAN1044AV-Q1

Hi,

We are using TCAN1042V-Q1 iwth Vio as 3.3V and Vcc as 5V. We are seeing that when we measure the voltage on TX pin with nothing connected to it through a multimeter, it comes as 2.7V. Is this normal, we expected it to be 3.3V since TXD is pulled up to Vio.

  • Shyama,

    Please use TCAN1044AV-Q1 in place of TCAN1042V-Q1. The TCAN1044AV-Q1 device is in the newer technology that will support future projects with increasing supply over time.

    Yes, this is common for the input TXD. Note that this is an input, not an output. Even measurement tools can impact the voltage of the pin.

    Note the leakage current of the pin, given as IIH and IIL in the data sheet. These are in the microampere range, so they are extremely weak leakages that are not strong enough to act as pull-ups against an externally applied signal.

    Best,

    Danny