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Original question:

TLV3012: is input series resistor needed?

TLV3012-Q1: Inputs clamping

Alex Teryohin
Prodigy 105 points
Part Number: TLV3012-Q1
Other Parts Discussed in Thread: TLV3012

Hi all.

We use TLV3012AQDCKRQ1 (i.e. TLV3012-Q1 / SC-70 footprint).

  • Does this comparator has clamping diodes at its inputs?

            It looks like it has calamping diodes due to absolute maximum voltage/current ratings, but it is not definitely written.

  • In case I have (V+) = 5V and the maximum input common mode voltage can be as high as 50V, is it sufficient to place 10K in series with both inputs? (I saw at some thread some TI expert has recommended 1K per 1V)
  • I'm trying simulating TLV3012, but I don't see voltage clamping neither at V- nor at V+ inputs. Does the model have this feature? (please see .lib parameters) Can somebody provide me with an updated model for PSpice?

* Part: TLV3012
* Date: 7/8/2021
* Simulator: PSpice
* Simulator Version: 17.4.0.p001
* EVM Order Number: N/A
* EVM Users Guide: N/A
* Datasheet: SBOS300B – FEBRUARY 2004 – REVISED JUNE 2004
*
* Model Version: 1.0

Sincerely,

Alex

  • 0
    TI__Guru 53826 points

    Hello Alex,

    The TLV3012-Q1 DCK has ESD clamping diodes to the supplies, but NOT between the inputs.

    Yes. Adding the series resistor is necessary. If the 50V is expected as part of normal operation, we recommend adding external clamping (either a <5V zener to GND and/or a diode clamp to the supply).

    No, the model does not seem to have any ESD clamps. You can add the diodes externally, as shown above.

    Do note that the new TLV3012B-Q1 has failsafe inputs and does NOT have the upper internal ESD diodes to the V+ supply, so external clamping to <5.5V  is required.

    I would highly recommend adding the external clamps and not relying on the internal ESD diodes.

  • 0
    Prodigy 105 points

    Hello Paul,

    Thanks for your quick response.

    Do you think the comparator can survive 50V/1ms pulse if no external clamping diodes are added? (and there are only 10Kohm resistors in series to -In and to +In)

  • +1 in reply to Alex Teryohin
    TI__Guru 53826 points

    Hi Alex.

    No. We have to say no...We cannot condone exceeding the Abs Max ratings. TI will always recommend adding the external clamps.

    Doing so unprotected would be at your own risk and will violate any TI warranties.

    50V/10k = 5mA, which is below the 10mA abs max limit - so it should not damage it...but proper operation is not guaranteed. It's your risk...

  • 0 in reply to Paul Grohe
    Prodigy 105 points

    OK. Thanks Paul.

    Hope it will not damage the component.