• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 48 subscribers
  • Views 204 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.

TL072: TL072 MCU written issue

Rock Shao
Expert 2985 points
Part Number: TL072

Tool/software:

Hi E2E,

The customer changed to the new PCN part and found could not written to MCU.

Please check the waveforms. Is there anything else that can be modified in the schematic? thanks.

FEBK OK

FEBK Fail

  • 0
    Guru 311890 points

    The guaranteed datasheet limits have not changed, but the new parts might behave differently for out-of-range voltages.

    What are the voltages at the input and output pins (1/2/3, 5/6/7)? Which ones are different between old and new?

    I do not see any DC feedback in the schematic. If you're using this device as a comparator, then note that the specific output levels are undefined, and are wider (near VCC+ and VCC−) for the new part.

  • 0
    TI__Guru 70561 points

    Hi Rock,

    Please reply to Clemens questions - What are the voltages at the input and output pins (1/2/3, 5/6/7)? Which ones are different between old and new?

    Due to the recent process change, the op amp's output behaviors may have changed in non-linear operation vs. Pre-PCN revision, when used as the op amp is used as comparator. The TL072's linear and datasheet performance remained unchanged, but the non-linear operation may be different (since the specified output levels may be undefined when the op amp is used as comparator). 

    https://www.mouser.com/PCN/Texas_Instruments_PCN20220615003_20220616135610237.pdf

    https://www.mouser.com/ProductDetail/Texas-Instruments/TL072CPWR?qs=st7IWvlL5%2FgwRZK%252BIBx0Gw%3D%3D

    In addition to measure the input/output voltages, you may replace a known op amps and replace the latest revision. If the Vout's voltage goes to opposite direction, that is likely the root causes. 

    If Vin+ > Vin-, the Vout should go high or to Vcc. 

    Due to the process change and undefined Vout state: the post PCN op amp may behave the following:

    If Vin+ > Vin-, the Vout will go low or Vee or GND. 

    Please confirm that this is the non-linear output behaviors from the latest TL072C's op amp in your circuit. Please let us know. 

    Best,

    Raymond