I'm building a circuit with a lm324 IC, not all of the sections are used.
what need to be done with unused inputs and outputs ??
Thanks

 

Connect the non-inverting input to 0V and the inverting input to the output of that amp.

 

I'm building a circuit with a lm324 IC, not all of the sections are used.
what need to be done with unused inputs and outputs ??
Thanks

Generally speaking, for any unused pins, tie inputs to either + or ground, using something like a 10K-ohm resistor. This limits the current to a reasonably low value, but strong enough to keep the pin where you want it.

Leave outputs unconnected/floating.

The only deviation is if the datasheet for the IC tells you different.

 

Post #2, yes.
Post #3, no.

Tying both inputs to the same potential can let the amp run "wide open" but not saturated and break into oscillation. This is possible for all opamps, but especially true of the LM324 because its input common mode range extends below the negative rail. Either go with post #2, or tie one input high and the other input low (through resistors), and let the output float.

ak

 

what need to be done with unused inputs and outputs ??

generally it doesn't matter: most of them have clamping diodes on the input pins.

if I care about current consumption and accidentally getting wires on to those pins, I would put a serial resistor on them, like 10k, and tie the input to vcc (for pnp inputs) or gnd (for npn inputs).

 

I also agree with post #2.
No possible problems and no added resistors.

 

generally it doesn't matter:

Actually, while it might not matter for some specific devices, *generally* it does matter - a lot. Unconnected inputs are potential problems in several different domains. Unconnected outputs generally are more safe, but there is no one-size-fits-all rule.

ak