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SN74HCS596: Clamping Voltage

Part Number: SN74HCS596

Hi Team,

Question about the Open Drain Shift Register SN74HCS596PWR.

According to the datasheet, it has a clamping current of up to +-20mA. My question is about the clamping voltage. Some other part say here, that they are able for up to 33V clamping voltage. In the datasheet of this part the volage isn't metioned seperatly.

Can I apply a voltage of 24V or max 30V to the inputs, if I stay unter the defined clamping current? Or is the Voltage maxed to 7V as this is the max supply voltage.

Thank you.

-Mark

  • There are simple silicon diodes from the I/O pins to VCC. When the clamp current is limited to less than 20 mA, the diode forward voltage is small, probably less than 1 V.

    So it is not possible top apply something like 30 V directly to the pin. But if you have a current-limiting resistor, most of the voltage will be dropped over the resistor.