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TLV9002: TLV9002 VS SGM2358 Stand-by current

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Replies: 4

Views: 122

Part Number: TLV9002

Dear TI experts:
        My custom use lm358 for current detcet, however the product stand-by current was over limit.
so he consider use SG Mirco  SGM2358 and TI  TLV9002 replace.
compare both parameter, tlv9002 are all beter than competitors, But unfortunately the product stand-by current worse than competitors.
i was puzzled, the PCB are all the same, only p2p replace the amplifier.

TLV9002 Stand-by current:  4.86mA;
SGM2358 Stand-by current:4.45mA.
sch as following, the parameter can be optimization? thanks


  • Hello,

    Over 4mA for this circuit seem very high. Is the current for the whole application (that includes more circuitry)?

    By standby, do you mean no input signal? If standby could be replaced by shutdown mode, that would help reduce the current draw by a lot.

     

    Regards,
    Ronald Michallick
    Linear Applications

    TI assumes no liability for applications assistance or customer product design. Customer is fully responsible for all design decisions and engineering with regard to its products, including decisions relating to application of TI products. By providing technical information, TI does not intend to offer or provide engineering services or advice concerning Customer's design. If Customer desires engineering services, the Customer should rely on its retained employees and consultants and/or procure engineering services from a licensed professional engineer (LPE).

     

  • In reply to Ron Michallick:

    User,

    The typical currents per amplifier in the datasheet is LM358 = 300uA, SGM2358 = 400uA, TLV9002 = 60uA

    TLV9002 is the clear winner here. Yet, the measurements show otherwise. Is this repeatable?

    My guess is below as I don't know the actual voltages of any node other than the 5V supply (which is also assumed).

    <guess>If SGM2358 had a negative input offset error then the 0mV input would make output railed low, both outputs in fact. If an output rail low state causes the SGM bias current to drop dramatically then its quiescent could in theory be lower. A positive offset device would have a not zero 1st amplifier and all the current savings will be lost <\guess>

    In my experience some op amps have odd behavior (like bias current change) when used in "comparator mode", any nonlinear state. I don't know if that is the case here. Try adding a little negative bias to pin 6 (via a resistor) to get pin 7 higher than ground. Then check supply current again.

    Regards,
    Ronald Michallick
    Linear Applications

    TI assumes no liability for applications assistance or customer product design. Customer is fully responsible for all design decisions and engineering with regard to its products, including decisions relating to application of TI products. By providing technical information, TI does not intend to offer or provide engineering services or advice concerning Customer's design. If Customer desires engineering services, the Customer should rely on its retained employees and consultants and/or procure engineering services from a licensed professional engineer (LPE).

     

  • In reply to Ron Michallick:

    Dear TI:

    yes ,it can repeatable.
    custom use the op amps in "comparator mode", can you give me more clean advice to improve the parameter.
    or tlv9002 is the right part  for this suitation. thanks

  • In reply to user6187612:

    My best and easiest method to understand is to unsolder and lift pin 8 of the op amp for both designs and place a current meter between the 5V supply and pin 8 to see how much really flow through the op amps.

    Regards,
    Ronald Michallick
    Linear Applications

    TI assumes no liability for applications assistance or customer product design. Customer is fully responsible for all design decisions and engineering with regard to its products, including decisions relating to application of TI products. By providing technical information, TI does not intend to offer or provide engineering services or advice concerning Customer's design. If Customer desires engineering services, the Customer should rely on its retained employees and consultants and/or procure engineering services from a licensed professional engineer (LPE).