Can I directly connect enable pin to ground? I am not going to use it.
Also can I connect all unused pins of LM324 op-amp to ground through single resistor or what configuration does it need?
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Sign up to join this communityCan I directly connect enable pin to ground? I am not going to use it.
Yes, generally it is good practise to tie all unused inputs of digital devices to eiter GND or positive supply voltage.
Also can I connect all unused pins of LM324 op-amp to ground through single resistor?
You can, but that would waste power; instead tie the negative input of each unused opamp to its output (which forms a voltage follower) and the positive inputs of all unused opamps to halfway between positive and negative supply voltages, using a resistor divider (or GND in the case of split supplies). E.g. like this (shown for a single opamp):
For more details about opamp termination, see Properly terminating an unused op amp and What shall we do with the unused opamp .
Yes, you can connect an input directly to ground. Inputs are high impedance so they're like a big resistor anyway.
As for the op-amp, that depends on the pins you're not using. As a general rule of thumb:
So you can connect your op-amp inputs together and ground them through a resistor (though I'd be inclined to only group the same type of inputs; one resistor for all the inverting, and one for all the non-inverting), but each output must have its own resistor.
You can tie the enable pin directly to ground, for the op amp just leave the unused outputs not connected and connect the unused inputs to ground.
The op amp output is (ideally) a voltage generator. If you connect both inputs to ground, or just tie them together, the output should be zero and there should be no issues. The output won't be zero though because of noise, offset, production imperfections or whatever, so you have this output that wants to drive ground, a power rail, and that's bad. It can break, but if it doesn't it dissipates power.