• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 2 answers
  • Subscribers 47 subscribers
  • Views 149 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM748QML: LM748QML

yenwu lo
Prodigy 140 points
Part Number: LM748QML

Tool/software:

 Dear Technical Support, not sure what the slew rate of LM748QML opamp? it seems that the datasheet is not listed, Look forward to hearing from you when convenient. 

thanks 

yenwu lo, attached is the related datasheet for your easy reference. Hope it helps.

lm748qml.pdf

  • 0
    TI__Genius 11096 points

    Hello yenwo lo,

    This is far form a modern part, so some information has been lost over time. 

    I have found this data for output response in a large signal input:

    It looks like a SR of about .5V/us at 30V supply. 

    Keep in mind this is a typical curve, there is no way to state a min/max slew rate since this is not in the datasheet specification table. 

    Please let me know if you have any questions.

    Best,

    Jacob

  • 0
    Prodigy 140 points

    HI, Jacob,

    1. I seem to find a LM748 datasheet from National Semiconductor  ( attached) which has a similar slew-rate chart in P.4 copied below ( #1 copy) & it is similar to what you shown in your previous email below.

    So I guess this might be where the chart is from.

    1. I noticed 2nd & 3rd pin pin-assignment of this LM748 device ( see #2 copy below)  is just opposite of the  2nd pin & 3rd pin of LM748QML ( see #3 copy below). LM748QML related datasheet is attached also for easy reference.

    not sure if there is mistake in the original LM748 datasheet or in the LM748QML datasheet?

    Can you help to find out which datasheet has the mistake if possible and convenient?

    Thanks and look forward to hearing from you when convenient.

    yenwu lo  

  • 0 in reply to yenwu lo
    Prodigy 140 points

    HI, Jacob, A 3rd question about this related OPAMP parts = LM748QML is :

    Does LM748QML need external compensation for proper operation?

    or

    it has internal compensation cap installed inside the IC already, so an external compensation cap is not necessary?.

    Thanks.

    yenwu lo

  • 0 in reply to yenwu lo
    TI__Genius 11096 points

    Hi yenwo lo,

    Happy to offer what help I can. 

    This device is very challenging to locate information for, but I can share some details here.

    The LM748QML datasheet is correct regarding the pinout. The difference in pin order comes from the fact that the commercial device has a pinout in the traditional DIP-8 package. The commercial device with a similar name is going to have a different bonding diagram than the unique die which is in the LM748QML.The OPA627SM uses this same metal can pinout as LM748QML, just without the compensation pins. This means both datasheets are correct for pinout. 

    I am not able to find any information regarding the compensation capacitor. I would imagine you need to include an external compensation capacitor for the QML device, but I do not have any of this material on hand to confirm.

    Please let me know if you have any questions.

    Best,

    Jacob