Difference Amplifier Resistor Mismatch Calculator
Calculate differential gain and common-mode leakage of an ideal four-resistor difference amplifier.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Decompose the exact resistor-ratio result using Vdiff=V2−V1 and Vcm=(V1+V2)/2.
Vout=b V2−a V1; a=R2/R1; b=(1+a)R4/(R3+R4); Ad=(a+b)/2; Acm=b−a
Worked example
Matched10k/100k resistor pairs give differential gain10, zero ideal common-mode gain and1 V output for V2−V1=0.1 V.
Assumptions and input details
Ideal op amp and exact entered resistances. No amplifier intrinsic CMRR, input impedance loading, tolerances distribution, bandwidth or rail/saturation limits. Infinite ideal CMRR is shown as undefined rather than a finite claim.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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