Differential Amplifier - Op-Amp Designs
A very simple one op-amp diff amp. This amplifies the difference between two inputs Vp and Vn the low impedance of this configuration is a drawback, but can be used in analog computing. Optimum VCC VDD can be +12/-12. AC signals common to Vp and Vn are canceled by this configuration.
Differential Amplifier - Op-Amp Circuits
Use a capacitor like 10nF plastic from pin 2 to 3 or across R2 to make circuit stable. For AC applications use LF351 TLO71 as they have good slew rate and also are FET inputs. For AC applications use a capacitor (1uF) in series with Ri to block DC Components.
The Inputs have asymmetrical input impedance this affects CMRR, also use 1% tolerance MFR resistors for Rf and Ri.
Vout = ( Vp - Vn ) * ( Rf / Ri )
Slide the Potentiometers just like you would operate a Sliding Control. Drag the Knob on Pot to increase or decrease the resistance. The Resistance is shown is blue letters and dynamically alters value as you slide the pot.
Differential Amplifier - Op-Amp Circuits
Use a capacitor like 10nF plastic from pin 2 to 3 or across R2 to make circuit stable. For AC applications use LF351 TLO71 as they have good slew rate and also are FET inputs. For AC applications use a capacitor (1uF) in series with Ri to block DC Components.
The Inputs have asymmetrical input impedance this affects CMRR, also use 1% tolerance MFR resistors for Rf and Ri.
Vout = ( Vp - Vn ) * ( Rf / Ri )
Slide the Potentiometers just like you would operate a Sliding Control. Drag the Knob on Pot to increase or decrease the resistance. The Resistance is shown is blue letters and dynamically alters value as you slide the pot.