LM358: voltage input range

Yahia Abdelli

Prodigy 20 points

Part Number: LM358

Hello,

i have i have a single supplied LM358 op amp (+12/0) volts shown in the picture

the question is would the signal of (15uA/15mV) effect the -input? (damage the op amp) regardless the out put signal

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Yahia,

no, this signal would not damage the LM358. But if it goes more negative then -0.3V, then it might.

But the circuit will not work, because the output cannot go negative. It even can't fully go down to 0V:

yahia.TSC

Kai

0 Ron Michallick over 5 years ago

TI__Guru*** 140136 points

Yahia,

15mV / 15uA won't cause damage to LM358. If the output load doesn't require LM358 to sink current, then DC output can be as low as 1mV or the value of Vio (if Vio is positive). Are you trying to get half wave rectification with this circuit?

0 Yahia Abdelli over 5 years ago in reply to Ron Michallick

Prodigy 20 points

i need to amplify the 15 or 30 mVAC (the input) and then rectify it to command an 2n2222

0 Ron Michallick over 5 years ago in reply to Yahia Abdelli

TI__Guru*** 140136 points

Yahia,

There are a lot of ways to do this. What is the frequency range of the AC signal?

Here is one way. Add filter capacitors on pin 3 and 3 if supply is not clean.

LM358 2n222.TSC

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LM358: voltage input range