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ASing.15
Associate II
Nov 23, 2021 6:17 AM UTC
Solved

STC3115AIJT maximum current measuring capacity ?

Hello,

I am working with STC3115 and I would like to know, the maximum charging current that I can measure with it?

    This topic has been closed for replies.
    Winfred LU
    Winfred LUBest answer
    ST Employee
    Nov 24, 2021 1:16 AM UTC

    Given the calculation:

    Vin_gg = Rcg * IMax

    with maximum input voltage (Vin_gg) at 40 mV and minimum current sense resistor (Rcg) at 5 mohm,

    the maximum application charging current (IMax) will be 8A.

    4 replies

    Peter BENSCH
    ST Technical Moderator
    Nov 23, 2021 10:48 AM UTC

    Well, that is a question of design: the battery current is not measured directly, but via a shunt, which is why there is theoretically no upper limit.

    However, the internal Sigma-Delta ADC is limited to 14bit and has a typical LSB value of 5.88µV. So the larger you make the current, the lower the resistance of the shunt and the coarser the measurement will be.

    Regards

    /Peter

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    ASing.15
    ASing.15Author
    Associate II
    Nov 24, 2021 4:27 AM UTC

    Thanks, Peter for your prompt reply.

    Winfred LU
    Winfred LUBest answer
    ST Employee
    Nov 24, 2021 1:16 AM UTC

    Given the calculation:

    Vin_gg = Rcg * IMax

    with maximum input voltage (Vin_gg) at 40 mV and minimum current sense resistor (Rcg) at 5 mohm,

    the maximum application charging current (IMax) will be 8A.

    ASing.15
    ASing.15Author
    Associate II
    Nov 24, 2021 4:28 AM UTC

    Thanks, Winfred for your prompt explanation.