Unused channels on a buffer

Hi,

What is the best way to handle unused channels in a tristate buffer (a 74act125d to be exact) ground both input and control or don't worry about it? I was trying to determine which would cause the lowest power consumption but can't seem to work it out from the datasheet. There is mention of ΔIcct being 1.5ma per input, but I'm not sure I'm interpreting that correctly, are they saying that each channel adds 1.5ma to the current on VCC when tristated?

Also, is anyone aware of a buffer with the same specs but in a single channel? I keep coming up with ones that are active when control is high, but the above part number is active low.

Thanks.

If you tri-state your unused buffer it should only draw 5ua. I would tie the unused input to either +v or gnd, but I don't think it will matter too much either way since the output is tri-stated. I would base your choice on which is easier to route.

You can generally expect small scale digital CMOS ICs to dissipate power only when they are changing state, as long as you have no resistive loads on the outputs, and the input voltages are either VCC or GND.