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LMV324: Difference between the models with no TI mark and models with TI mark

Tsz Him Timothy Chan
Prodigy 20 points

Part Number: LMV324

Tool/software:

My Customer claimed that the output waveform was different between the models with No TI mark and models with TI mark. (Please check attached file)

In order to make design changes, please help to confirm any differences in specifications other than those listed in the data sheet.

  • 0
    TI__Guru**** 171066 points

    Hello Tsz, welcome to the TI e2e forums. 

    I do not a see an attached file. The TI mark change is not related to your output waveform.

    There is a different change, slew rate per data sheet large signal specification is a little faster. Small signal slew rate is a little slower.

  • 0 in reply to Ron Michallick
    Prodigy 20 points

    Ron, thank you for your advice. 


    My customer's development team believe there is no effect from the slew rate. 

    As I know the TI mark change is not related to the output waveform, is there any change in output waveform for this item previously? 

    If yes, please advise the change and describe. 

    My customer hasn't made any changes to the circuit.
    However, the output waveform is clearly changed. 

    My customer would like to know which items of which ICs are having an impact so that they can consider alternatives. 

    Thank you

  • 0 in reply to Tsz Him Timothy Chan
    TI__Guru**** 171066 points

    Tsy,

    Where does pin 14 output go? Is there any capacitors? Direct capacitance is problematic for op amps. 

  • 0 in reply to Ron Michallick
    Prodigy 20 points

    Ron, please find the feedback from by customer as below. My customer are requesting a CPR CPR251125559 but being rejected previously. 

    Pin 14 OUT is connected as a BIAS voltage to another location (e.g., the non-inverting input of another op-amp), but it is not directly connected to a capacitor.

    We do not believe the issue is caused by variation in slew rate, as the circuit is only operating within the audible frequency range.

    We are not suggesting that the "new" reel op-amp is operating outside of the datasheet specifications. However, it is clear that some electrical characteristics have changed following the printing update.

    We are considering switching to a new TI op-amp, but we are unable to make a selection because the root cause of the noise problem is still unknown.

    It would be very helpful if you could analyze both the old and new op-amps (which we will send) and advise us of any differences.

  • 0 in reply to Tsz Him Timothy Chan
    TI__Guru**** 171066 points

    Tsz,

    Then abnormal waveform appears to be variable frequency 400kHz-600kHz ; does this frequency also appear at pin 12, ground or supply voltage?

    What is the occurrence rate on the new reel? All, some, one?  

    There is nothing in new design that would make this signal with out cause.  How far away does this output trace travel. Does it parallel a signal with the offending frequencies?