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TMUX1308A: TMUX1308AQPWRQ1

Jacob Bratkowski
Prodigy 20 points
Part Number: TMUX1308A

Tool/software:

In section 8.3.6.2 of the datasheet, it outlines the conditions and reaction of the part when a channel is selected, and an overvoltage event occurs. When this happens, the datasheet says that the protection circuitry is partially active. Does this mean that it is active only enough to act as a current sink in order to pull down the output to Vdd? Other than the current limiting resistor on the input, will I need further downstream protection, or is the ground shunt enough? Thank you.

  • 0
    TI__Intellectual 1210 points

    Hi Jacob,

    When an overvoltage occurs on a selected channel, the "partially active" protection circuitry does not pull the output down to VDD. Instead, it means that a portion of the overcurrent is shunted to ground, some of the overvoltage and current will still pass through the switch from the input to the output. Because the overvoltage condition is passed downstream, the internal ground shunt is not sufficient on its own to protect subsequent components in your circuit.

    The external current-limiting resistor is intended to protect the multiplexer itself from damage, not the downstream circuitry. So, you will possibly need to add further downstream protection, such as clamping diodes, if your downstream components cannot tolerate the potential overvoltage at the multiplexer's output.

    Thank you,
    Arya