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ISOW7740: Need to add PU on EN-Pin (Pin-8)?

Part Number: ISOW7740


just to be clear on my side:

I do not need the /FLT function but want to enable the DC/DC at all times.

Do I need to connect Pin-8 (EN/ \FLT) to VIO (Pin 1) with a Pullup or not?

Figure 9.5 in Datasheet claims there already is a PU to VIO (550k)

I would like to leave Pin-8 open.

EN-IO1 and EN-IO2 can be open to enable Input/ Output-ports and they have 550k PU (internal) as well.



  • Hi Mathias,

    Thanks for reaching out and for your interest in ISOW7740.

    Your understanding is correct, all the enable pins including the EN/FLT pin can be left open to enable their respective function blocks. Although this is fine for normal operating conditions, having an external pull-up resistor (like 4.7kΩ) will pull the enable pins to a strong HIGH and make these pins immune to any external noise.

    I hope this answers your question, thanks.

    Koteshwar Rao

  • Yes, it answers my question to my complete satisfaction. :-)