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EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. If the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less than maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

Note: If your max value is your normal max input then you will never know if it is actually over that.

NOTE 2: You want to add your limiting after all the amplification stages. If you try to do it earlier the values become so low that the tolerances involved swamp the signal. The op-amps themselves will not care much if the signal is too strong unless it reaches the rail. At that point you may get a lot of distortion.

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. If the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less than maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

Note: If your max value is your normal max input then you will never know if it is actually over that.

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. If the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less than maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

Note: If your max value is your normal max input then you will never know if it is actually over that.

NOTE 2: You want to add your limiting after all the amplification stages. If you try to do it earlier the values become so low that the tolerances involved swamp the signal. The op-amps themselves will not care much if the signal is too strong unless it reaches the rail. At that point you may get a lot of distortion.

2 added 97 characters in body
source | link

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. IIf the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less thatthan maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

Note: If your max value is your normal max input then you will never know if it is actually over that.

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. I the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less that maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. If the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less than maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.

Note: If your max value is your normal max input then you will never know if it is actually over that.

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source | link

EEK 741s...

You can add either limiting diodes or zeners to the circuit but be aware that may change the linearity a little.

The question you have to ask is will the input itself survive a voltage greater than the ADC reference value. I the answer is yes, then limit it to under the max voltage it can take. Possibly with a forward pointing Zener over R10. You should also make sure the thing can never go negative (whatever the input can handle) either.

More often it is prudent to back off on the gain so your input to the ADC is a little less that maximum for the normal signal range. While doing that is it often convenient to chose a maximum value that is convenient from a human perspective. For example max value = 1000 for a 1024 bit DAC.