differential signal to single ended

[karbiuch]

I have a sensor that has output + -2.5V, max 500k hz. I would like to have a output signal 0-5V. I need to convert differential to singel ended, +-2.5V to 5V.

I tried to use a non-inverting amplifier with a reference voltage - it works. However, when input signal is 0V the output signal is equal to reference voltage 2.5V. I would like to achieve effect when the input is 0V the output is 0V.


Is there a better way of conditioning signal from the differential to single-ended? How to use fully differential amplifier with Vocm?

 

[BradtheRad]

Please clarify whether your signal is (a) bipolar referenced to 0V ground, or is it (b) truly differential and not referenced to ground?

If 'A' then you can use a simple potentiometer, dialing between your signal and +5V. This lifts your signal up into the positive region.

If 'B' then you need to ground reference a differential signal. An op amp can be configured for this. It needs a bipolar supply, so it can handle the negative incoming waveform.

 

[karbiuch]

I tried to do it with fully differential amplifier (power supply +-10V) . At "Vocm" input I gave 2.5V. It works, but when input signal is 0V then output is 2.5V - it should be 0V. Can I have an example? It can be an amplifier with symmetrical power.

 

[FvM]

but when input signal is 0V then output is 2.5V - it should be 0V.

The requirement seems to contradict the previously specified +/-2.5 to 0..5V mapping. Would you mind to clarify the intended amplifier operation as an input/output voltage table.

You want Vout = 0 for Vin = 0. What's the expected output for Vin = -2.5 and Vin = +2.5V?

 

[karbiuch]

Ymm,. the sensor has an output:

Output voltage differential [V] 0 ... 2.5 (@ high impedance load)
Output common mode voltage [V] 0

I have to convert the output voltage to asymmetrical signal (singel ended) . What does it mean? Apparently badly I understood it. Could I have a graph of signals that I was sure that I understood it well.