Calculadora de Amplificador Diferencial
Calcule o ganho e a saída de um amplificador diferencial com resistores de entrada e realimentação.
Differential Gain
5.00 V/V
Differential Gain vs Non-Inverting Input (V1)
Formula
## Differential Amplifier Amplifies the difference between two inputs while rejecting common-mode signals. ### Formula (matched resistors) **V_out = (Rf / R1) x (V1 - V2)** Requires R1 = R2 and Rf = Rg for proper common-mode rejection.
Exemplo Resolvido
V1 = 3 V, V2 = 1 V, R1 = 10k, Rf = 50k.
- 01Gain = 50 / 10 = 5 V/V
- 02Differential input = 3 - 1 = 2 V
- 03V_out = 5 x 2 = 10 V
Perguntas Frequentes
What is common-mode rejection?
The ability to reject signals common to both inputs. Ideal CMRR is infinite; real circuits are limited by resistor matching.
How accurate must resistors be?
Use 0.1% tolerance resistors for good CMRR. 1% resistors give roughly 40 dB CMRR.
When do I need an instrumentation amplifier?
When you need very high input impedance and high CMRR. Instrumentation amps use three op-amps.
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