Post History
I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit: S...
#4: Post edited
by
Elleanor Lopez
·
2025-06-06T12:28:37Z (7 days ago)
Separated schematic from simulation, added datasheet link
- I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit:
- Simulation does what I would expect and want the circuit to do, however, the differential input side uses Vref(V2) as a reference, which is coupled to ground only capacitively. My concern is if this is a valid approach, since the opamp specifies input common mode voltage of (V-)-100mV to (V+)-1.5V.
- In my mind the input range now is from 0.5V to 4.5V, since the reference point is 2.5V. Is this valid or am I violating something?
- 
RG is left floating to have a gain of 1.
- I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit:
- 
- Simulation results:
- 
- The opamp used is [INA188](https://www.ti.com/lit/ds/symlink/ina188.pdf?ts=1749202663359)
- Simulation does what I would expect and want the circuit to do, however, the differential input side uses Vref(V2) as a reference, which is coupled to ground only capacitively. My concern is if this is a valid approach, since the opamp specifies input common mode voltage of (V-)-100mV to (V+)-1.5V.
- In my mind the input range now is from 0.5V to 4.5V, since the reference point is 2.5V. Is this valid or am I violating something?
- 
- RG is left floating to have a gain of 1.
#3: Post edited
by
Elleanor Lopez
·
2025-06-06T12:09:53Z (7 days ago)
- I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit:
- 
- Simulation does what I would expect and want the circuit to do, however, the differential input side uses Vref(V2) as a reference, which is coupled to ground only capacitively. My concern is if this is a valid approach, since the opamp specifies input common mode voltage of (V-)-100mV to (V+)-1.5V.
In my mind the input range now is from 0.5V to 4.5V, since the reference point is 2.5V. Is this valid or am I violating something?
- I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit:
- 
- Simulation does what I would expect and want the circuit to do, however, the differential input side uses Vref(V2) as a reference, which is coupled to ground only capacitively. My concern is if this is a valid approach, since the opamp specifies input common mode voltage of (V-)-100mV to (V+)-1.5V.
- In my mind the input range now is from 0.5V to 4.5V, since the reference point is 2.5V. Is this valid or am I violating something?
- 
- RG is left floating to have a gain of 1.
#2: Post edited
by
Elleanor Lopez
·
2025-06-06T11:30:03Z (7 days ago)
Biasing a differential input signal to opamp
- Biasing a differential opamp input
#1: Initial revision
by
Elleanor Lopez
·
2025-06-06T11:29:37Z (7 days ago)
Biasing a differential input signal to opamp
I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit:  Simulation does what I would expect and want the circuit to do, however, the differential input side uses Vref(V2) as a reference, which is coupled to ground only capacitively. My concern is if this is a valid approach, since the opamp specifies input common mode voltage of (V-)-100mV to (V+)-1.5V. In my mind the input range now is from 0.5V to 4.5V, since the reference point is 2.5V. Is this valid or am I violating something?