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TPS2H160-Q1: What's the tolerance of dK(CS)/K(CS) related to?

song.lin
Intellectual 260 points
Part Number: TPS2H160-Q1

Is this tolerance related to K(CS) or current sense, that's different.

Let's define K(CS)min=0.15K(CS) according to the max tolerance of 85%

then ICSmax=Iout/K(CS)min

△I%=(Iout(read)-Iout)/Iout

       =(ICSmax*K(CS)-Iout)/Iout

       =(Iout/K(CS)min*K(CS)-Iout)/Iout

       =566%

  • 0
    TI__Mastermind 32650 points

    Hi Song,

    This is just current sense accuracy. This just refers to the variation in the current sense output at specific load currents. For example for an Iout of 25mA, the current sense will output Iout/Kcs. The variation of this output is bound by +-17%.

    Thanks,

    Shreyas

  • 0 in reply to Shreyas Dmello
    Intellectual 260 points

    Hi Shreyas

    I want to calculate the WCCA with K(CS), that's why I want to know the tolerance of K(CS).

    With this "This is just current sense accuracy. This just refers to the variation in the current sense output at specific load currents. For example for an Iout of 25mA, the current sense will output Iout/Kcs. The variation of this output is bound by +-17%."

    I will calculate the tolerance of K(CS) @Iout=5mA as follow:

    K(CS)min=1/(1+0.85)*K(CS)=0.54*K(CS)

    K(CS)max=1/(1-0.85)*K(CS)=6.66*K(CS)

    With above K(CS)min and K(CS)max, we can calculate Iout/K(CS):

    [Iout/K(CS)]min=Iout/K(CS)max=0.15*Iout/K(CS)

    [Iout/K(CS)]max=Iout/K(CS)min=1.85*Iout/K(CS)

    Which equal to the 85% tolerance in the datasheet.

    Could you please help check if that's right?

  • 0 in reply to song.lin
    TI__Mastermind 32650 points

    Hi Song,

    What this is referring to is the variation of Kcs and therefore the output.

    The calculation is: (ICS × K(CS) – IOUTx) /IOUTx × 100 

    So for example for an Iout of 100mA, the 4% variation means that the Ics*Kcs will result in a value of 96mA on the min side and a 104mA on the max side.

    Thanks,

    Shreyas