ISO7740: iso7740 unused channel

christophe duchemin

Part Number: ISO7740

Hello,

A simple question about unused channels of digital isolators.I generally ground the input of unused channels. Do we need to add a resistive load on the output?

Regards,

Christophe Duchemin

over 1 year ago

0 Aaditya V. over 1 year ago

TI__Genius 17295 points

Hello,

Thank you for your Inquiry.

For unused input pins on digital isolators, it is best to keep them connected in a way to maintain the default state, which allows for lower current consumption and helps the device be more immune to noise.

For example, The ISO7740F has a default LOW state. Unused pins can be connected to ground to maintain the default LOW state. The ISO7740 device (no F suffix) has a default HIGH state. unused pins for the non-F model can be connected to a pull-up resistor to maintain the default state.

The output of the device is recommended to be left open when the channel is unused and no resistive load is needed.

For more information on unused channel input/output pins, please refer to this FAQ: https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/732667/faq-can-channel-input-output-pins-on-a-digital-isolator-be-left-floating

Regards,
Aaditya Vittal

Isolation

Isolation forum

ISO7740: iso7740 unused channel