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Original question:

LM358: Difference between LM358AP and LM358P

LM358: LM358N (ST) Replace by LM358AP (TI)

user5321866
Prodigy 190 points
Part Number: LM358

Hi Team,

one of my customer  using LM358AP (Dual Opamp) in their Fire alarm System .

 

Earlier they are using ST LM358N that we replaced by LM358AP .Now out of both  OPamp (LM358AP) second Opamp do not operate.

 

Please check  below observation tables of both devices.

 

LM358AP (TI)

LM3358N(ST)

Pins

V at Non operating

V at Operating condition

Pins

V at Non operating

V at Operating condition

IN1-

21.8

17

IN1-

21.8

18

IN1+

20.4

20.1

IN1+

20.3

20.1

OUT1

 

Working

OUT1

 

Working

IN2-

22.5

22.5

IN2-

22.5

22.5

IN2+

21.9

22.5

IN2+

21.8

22.5

OUT2

 

Not working

OUT2

 

Working

 

Please advise how we can resolve .

  • 0
    TI__Guru**** 157236 points
    Hello User,

    Why did you use 'working' and 'not working' as the descriptions for the outputs? What is the supply voltage?

    Assuming supply is >24V:
    Based on your table OUT1 'non op' should be VOL and 'op condition' should be VOH
    Based on your table OUT2 'non op' should be VOL and 'op condition' should be be linear, between VOL & VOH
    Because both inputs are the same it is working.
  • 0 in reply to Ron Michallick
    Prodigy 190 points

    Hi Ronald ,

    I mean to working  and not working  to Getting O/P from Out1 pin of Opamp and not getting O/P from Out2 pin of pin respectively .

    Supply Voltage is 24V.

    Sorry i didn't understand your answer .

    My  issue is  when we are using TI opamp ,we did not get any output at OUT2 pin of Opamp .

    And In the same board if we  just replace TI OPamp by ST opamp  we get output at OUT2 pin .

    Please advise.

    Thanks

    Regards

    Rahul

  • 0 in reply to user5321866
    TI__Guru**** 157236 points

    Rahul,

    The LM358 does not have the ability to make the output high impedance therefore the output is always on.

    The output may be incorrect due to the input common mode range.

    With a 24V supply and full temperature range, the maximum input voltage is 22V (24V-2V).  Your table shows 22.5V which is close to the edge.

    Can you reduce the input voltage to 24V supply minimum - 2V?

  • 0 in reply to Ron Michallick
    TI__Guru**** 157236 points
    Rahul,

    It is your turn to answer my questions or for you to ask new questions.