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Vcc vs Icc plot of TL3474

Angelica Zamora
Prodigy 120 points
Other Parts Discussed in Thread: TL3474

Hello!

I'm assessing the possiblity of using a TL3474 quad OpAmp in order to replace an MC33074 (by ON Semi). I just need to confirm some information stated in datasheet. At last row of the table shown in page 4, it says that the Icc TYP is 3.5 mA per channel (for all cases). Then when I check the Figure 10 (in page 7), @25C says it is about 7mA. How do I match this information? Is the plot of Figure 5 for all the quad device?

Thanks for your help!

  • 0
    TI__Guru**** 166116 points

    Angelica,

    Figure 5 is just above 8mA for a VCC of 30V (+/-15V). which is just over 2mA per amplifier. This sample's ICC is significantly lower than the DS 3.5mA typical.
    Figure 5 is for the whole device, 4 channels.

  • 0 in reply to Ron Michallick
    Prodigy 120 points

    Hello Ron,

     

    Thanks a lot for your answer.

    3.5mA (from table) vs. 2mA (from plot) is a large difference. Is there any sigma value (assuming a normal behavior of the measurements) that I may take in order to find a more accurate value? Which would be the mean value 3.5mA or 2mA?

  • 0 in reply to Angelica Zamora
    TI__Expert 7250 points

    Hello Angelica,

    For Icc it is provided with a typical and maximum spec on page 4 in the datasheet. Usually if supply current is a concern then you would want to base the design on the maximum value for Icc. If the concern is due to your power supply being designed for a certain amount of current output then using the maximum supply current specification will allow you to account for a worst case scenario. Or if the application will be powered off a battery then this will allow you to calculate how long your battery will last. If you want an "average" value to base the same calculations off of then you could use the typical value. Just keep in mind that if you have a marginal design that is based on typical values you could run into problems, IE: battery not lasting as long as expected, or power supply voltage being pulled down due to excessive current draw.