SN74HC4020: Unused Outputs

Darren (FAE)

Part Number: SN74HC4020

If some of the outputs of the device are not needed, what kind of termination can be used?

It looks like this device uses LSTTL logic...and the DS mentions literature SCBA004, and that states unused inputs should be tied to VCC/GND via 1~10kΩ resistor.

But what about the unused outputs?

Regards,

Darren

over 4 years ago

0 Clemens Ladisch over 4 years ago

Guru 267140 points

See [FAQ] How do I terminate any unused channels of a logic device?

0 Emrys Maier over 4 years ago

TI__Guru* 96681 points

Hi Darren,

The HC logic family uses CMOS logic. There's a guide to logic families located here -- on page 7 there is a quick reference chart.

Either way, unused outputs should be left disconnected.

Logic

Logic forum

SN74HC4020: Unused Outputs