# Sense resistor / current shunt + current sense amplifier calculator

Calculate the output voltage of a current sense amplifier combined with a current shunt resistor - formula included.

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Don’t need a current sense amplifier? See our Sense resistor / current shunt calculator.

This calculator allows you to find out which sense resistor and current sense amplifier you need to use to obtain a specific amplifier output voltage at a specific current.

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[calculator-input name=“i” label=“sense current” unit=“A”][/calculator-input] [calculator-input name=“u” label=“amplifier output voltage” unit=“V”][/calculator-input] [calculator-input name=“G” label=“amplifier gain” unit=“V/V”][/calculator-input][calculator-expression name=“r” formula=“u/(i*G)” unit=“Ω”][calculator-expression name=“usense” formula=“i*r” unit=“Ω”][calculator-expression name=“p” formula=“i*i*r” unit=“W”]

[calculator-output name=“sense resistor value” unit=“Ω”] Your sense resistor has a value of <%= format(r, “Ω”) %> and drops <%= format(usense, “V”) %> at <%= format(i, “A”) %>. It dissipates <%= format(p, “W”) %> at maximum current.

The current sense amplifier the <%= format(usense, “V”) %> dropped by the sense resistor by <%= “G=” + format(G) %>, resulting in a maximum output voltage of <%= format(u, “V”) %>[/calculator-output]

[/calculator]

[latex display=“true”]R_{\text{sense}} = \frac{U_{\text{drop}}}{I_{\text{sense}} \cdot G_{\text{current sense amplifier}}}[/latex]

[latex display=“true”]U_{\text{sense,drop}} = I_{\text{sense}} \cdot R_{\text{sense}}[/latex]

[latex display=“true”]P_{\text{sense}} = {I_{\text{sense}}}^2 \cdot R_{\text{sense}}[/latex]