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Spehro 'speff' Pefhany
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Most of the noise (perhaps 1-2mVp-p) will be due to the reference, so putting a capacitor on the op-amp non-inverting input (with a series resistor in the case of the TL071) makes some sense. 100nF with a 20K series resistor (about 22-23K equivalent total) will give you a cutoff frequency of around 71Hz if I did the math right. Similar to @WhatRoughBeast's comment but with added series resistance.

On the other hand if you use a lower noise reference such as an LM4040-2.048 or -2.5 which has something like 250uVp-p noise typically, the capacitor and resistor may not be necessary, since the amplifier is contributing significantly.

Most of the noise (perhaps 1-2mVp-p) will be due to the reference, so putting a capacitor on the op-amp non-inverting input (with a series resistor in the case of the TL071) makes some sense. 100nF with a 20K series resistor (about 22-23K equivalent total) will give you a cutoff frequency of around 71Hz if I did the math right.

On the other hand if you use a lower noise reference such as an LM4040-2.048 or -2.5 which has something like 250uVp-p noise typically, the capacitor and resistor may not be necessary.

Most of the noise (perhaps 1-2mVp-p) will be due to the reference, so putting a capacitor on the op-amp non-inverting input (with a series resistor in the case of the TL071) makes some sense. 100nF with a 20K series resistor (about 22-23K equivalent total) will give you a cutoff frequency of around 71Hz if I did the math right. Similar to @WhatRoughBeast's comment but with added series resistance.

On the other hand if you use a lower noise reference such as an LM4040-2.048 or -2.5 which has something like 250uVp-p noise typically, the capacitor and resistor may not be necessary, since the amplifier is contributing significantly.

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Spehro 'speff' Pefhany
  • 422.6k
  • 23
  • 352
  • 950

Most of the noise (perhaps 1-2mVp-p) will be due to the reference, so putting a capacitor on the op-amp non-inverting input (with a series resistor in the case of the TL071) makes some sense. 100nF with a 20K series resistor (about 22-23K equivalent total) will give you a cutoff frequency of around 71Hz if I did the math right.

On the other hand if you use a lower noise reference such as an LM4040-2.048 or -2.5 which has something like 250uVp-p noise typically, the capacitor and resistor may not be necessary.