Hi
I want to use the 3-line to 8-line decoder chip, SN74HC138.

It has three enable lines - G1 (active high) and G2A and G2B (both active low). Since I want the chip to be permanently enabled, I want to tie G1 to 5V and G2A/G2B to GND. But do I need to use pull-up / pull-down resistors, or can I tie the pins directly to Vcc or GND?

Many thanks for your response,

Andre

I think you can just tie them. Pull resistors are only used so that the line has a passive default state that can still be changed.

If the inputs aren't high impedence (ie. a bunch of current will flow through them if you just tie them), then you need a resistor to limit the current. You probably don't.

Pull-up or pull-down resistors are not needed in this case. Just tie those inputs to Vcc or GND.

Thanks guys - much appreciated.
Andre