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.

TLV1701: Questions regarding Recommended Operating Condition on Supply Voltage

Part Number: TLV1701

Dear Sirs or Madams,

Please let me have the following two questions regarding Recommended Operating Condition on Supply Voltage;

Q1

The datasheet says that Minimum operational supply voltage is 2.2V, which means that TLV1701 is definately activated

on the condition that the supply voltage equals to 2.2V or is higher than 2.2V.

Please let me know the state of  Pin4(OUT pin) when TLV1701 is not activated because the supply voltage is low or 0V.

Is the pin set to Hi-Z? Or, is the pin fixed to Low?

Q2

Regarding the supply voltage, I now understand it is possible that TLV1701 works normally even when supply voltage is lower than 2.2V.

If possible, please let me know on what supply voltage TLV1701 can work normally at lower side.

Of course, I never plan to use TLV1701 on the condition that supply voltage is lower than 2.2V.

Through this question, I just want to roughly know from what supply voltage TLV1701 tends to start working normally.

Accurate information is not necessarily needed, and even rough value would be appreciated.

I know that it will be difficult to answer to this question, so if it is impossible to answer to this question, please let me know it.

In such case, I will not have further questions related to Q2.

Best regards,

Shinsuke Tanaka

  • Tanaka-san,

    Unfortunately, the TLV1701 does not have a POR circuit with known start up conditions before the device reaches it's minimum operating supply voltage, In this case, the output voltage would be indeterminate. We understand that this is an undesirable output state as the device is powering up. All of our newer devices has POR built in to give a fixed output state during start up. For push-pull devices, generally the output is held low during start up, and for open drain, the output is Hi-Z.

    If a known output state is critical for your design, we can suggest some other comparators with POR but would need some more info regarding the system your proposed TLV1701 is in, such as:

    • Supply Range
    • Input Range
    • Speed Requirements
    • Iq
    • What will output be driving? Does it need push pull or open drain output?

    Regarding your second question, could you point to where you found that the device could operate normally with Vs < 2.2V? Based on the datasheet, we guarantee that the part should start working at Vs = 2.2V (single supply) or Vs = +/-1.1V (Split Supply).

    Regards,

    Jonny

  • Dear Jonathan san,

    I appreciate your detailed explanations.

    I respond to your questions and comments below.

    >Regarding your second question, could you point to where you found that the device could operate normally with Vs < 2.2V?

    >Based on the datasheet, we guarantee that the part should start working at Vs = 2.2V (single supply) or Vs = +/-1.1V (Split Supply).

    I'm sorry for confusion.

    I have NOT confirmed/found that TLV1701 works at Vs<2.2V.

    But here, I want to talk about kind of "general" characteristics of all ICs/components.

    As you mentioned above, I know that the datasheet says TLV1701's minimum operational Vs is 2.2V,

    which means TI guarantees that TLV1701 "definately" works at Vs=2.2V or higher.

    And, in such case, I guess that actually TLV1701 works even under the condition that Vs is slightly lower than 2.2V,

    although TI does NOT guarantee the behaviors of TLV1701 at such Vs voltage region.

    (Otherwise, considring dispersions of TLV1701's component characteristics, it is impossible to

    guarantee that all TLV1701s definately work at Vs=2.2V or higher. )

    And, if my above guess is correct, I want to know from what Vs voltage TLV1701s "tend to" start working.

    Again, I do NOT plan to have TLV1701s work at Vs < 2.2V.

    The purpose of the above question is just to know the transient behaviors of TLV1701s,

    which are implemented on our past products, during powering up.

    But as I mentioned in my previous message, I guess it may be difficult to answer to the question

    because TI does NOT guarantee the behaviors at Vs<2.2V.

    So, if it is impossible to answer to it, please let me know it.

    In such case I will not have further quetions on this item.

    >If a known output state is critical for your design, we can suggest some other comparators with POR

    >but would need some more info regarding the system your proposed TLV1701 is in, such as:

    I appreciate your generous proposal.

    Actually, I don't have any plans to replace TLV1701s with new ones which have POR circuit,

    so I don't have any concrete requests to alternatives of TLV1701.

    But for future reference, would you please let me kow the way to know

    which comparators have POR circuit and which do NOT?

    Are there any descriptions on datasheets when the comparators have POR circuit?

    Best regards,

    Shinsuke Tanaka

  • Tanaka-san,

    I expect the part to "start working" generally around Vs = 2V, but again I cannot guarantee that it will work normally until Vs = 2.2V. I have ordered some samples to try and capture some transient start up data for you. I expect the samples to be in next week, and I will try to provide you data by two weeks from now. Due to COVID-19, shipments can be delayed and times in lab are limited for us, but will do my best to provide you data in a timely manner.

    I have added you as a friend so that we can perhaps take this discussion offline through email once I am able to collect some data.

    Would you be able to provide me the input conditions of your circuit so that I can try to collect data pertaining to your application as accurately as possible? Information I need would be:

    • Supply Range
    • Input Voltages (At IN+, IN-)
    • Pull-up Voltage
    • Pull-up Resistor Value

    For future reference, generally POR circuits are described in the "Detailed Description" section of the datasheet.

    Regards,

    Jonny

  • Dear Jonathan san,

    I appreciate your rapid response.

    >I have ordered some samples to try and capture some transient start up data for you. I expect the samples to be in next week,

    >and I will try to provide you data by two weeks from now.

    Wow!

    Actually this is so much beyond my expectation because I just wanted to know the value "if possible".

    I'm afraid that the above trial would consume your valuable time...

    But I appreciate your generous proposal so much.

    >Would you be able to provide me the input conditions of your circuit so that I can try to collect data

    >pertaining to your application as accurately as possible? Information I need would be:

    I appreciate your generous proposal again.

    But as mentioned previously, currently I just try to understand the transient behaviors of  TLV1701

    implemented on our past product, so I don't have any concrete requests on alternatives of TLV1701.

    >For future reference, generally POR circuits are described in the "Detailed Description" section of the datasheet.

    So, currently this information is sufficient and is much helpful for me.

    >I have added you as a friend so that we can perhaps take this discussion offline

    >through email once I am able to collect some data.

    I received "Friendship request" mail.

    I understand you want to discuss through emails from now on.

    So, should I close this topic by pushing "This resolved my issue" button?

    Best regards,

    Shinsuke Tanaka

  • Tanaka-san,

    Yes, please feel free to press the "This resolved my issue" button.

    When I have relevant data for this topic, I will ping you offline.

    Regards,

    Jonny