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TXU0304-Q1: Input current

Marco Rolando Perino
Prodigy 10 points
Part Number: TXU0304-Q1
Other Parts Discussed in Thread: TXU0304, TXB0104, , TXB0104-Q1

Tool/software:

Hello,

we would like to connect a single master on a single SPI bus to multiple devices as represented in the image below. Only one TXU0304 will be enabled at a time using the OE pin.

Among the devices that we are looking to, there is the TXB0104-Q1 and the datasheet states that: "For proper operation, the device driving the data I/Os of the TXB0104 must have drive strength of at least ±2mA", is there any similar indication for TXU0304-Q1?

Is this configuration possible current-wise if we consider to have up to 20 TXU0304-Q1 on the same bus? The master's GPIO should be able to provide up to 20mA.

Can you confirm that there is no conflict on MISO signal when only one TXU0304-Q1 is enabled?

Many thanks

  • +1
    Guru 317450 points

    The TXB requires the other devices to have higher drive strenghts because of its auto-bidirectional architecture. The TXU behaves like a buffer and does not have this problem.

    20 mA is more than enough.

    When OE is low, all outputs are disabled, i.e., they will not interfere with the signal on the line.