Do an Op-amps supply pins need to have the exact same nominal voltage?
Clash Royale CLAN TAG#URR8PPP
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By power supply unit should ideally output +12 and -12V, however the readings are closer to 12.2V and -11.8V.
Is this likely to cause a problem, even though I only need an output range of 10V to -10V?
op-amp negative-voltage
add a comment |Â
up vote
4
down vote
favorite
By power supply unit should ideally output +12 and -12V, however the readings are closer to 12.2V and -11.8V.
Is this likely to cause a problem, even though I only need an output range of 10V to -10V?
op-amp negative-voltage
The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
1
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
1
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17
add a comment |Â
up vote
4
down vote
favorite
up vote
4
down vote
favorite
By power supply unit should ideally output +12 and -12V, however the readings are closer to 12.2V and -11.8V.
Is this likely to cause a problem, even though I only need an output range of 10V to -10V?
op-amp negative-voltage
By power supply unit should ideally output +12 and -12V, however the readings are closer to 12.2V and -11.8V.
Is this likely to cause a problem, even though I only need an output range of 10V to -10V?
op-amp negative-voltage
op-amp negative-voltage
edited Aug 16 at 19:49
SamGibson
10.1k41436
10.1k41436
asked Aug 16 at 19:09
19172281
76111
76111
The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
1
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
1
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17
add a comment |Â
The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
1
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
1
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17
The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
1
1
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
1
1
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17
add a comment |Â
3 Answers
3
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up vote
11
down vote
If your op-amp can swing within 2.2V of the positive rail and within 1.8V of the negative rail under all possible load conditions, and if the inputs likewise are within the allowable common mode range then there is no problem.
There is no requirement for balanced voltages. You can use -0.1V and +20V if that works as indicated above (and, of course, if the op-amp can handle a 20.1V supply).
add a comment |Â
up vote
0
down vote
The PSRR specs include DC meaning , other than saturation near the rails, if bipolar outputs , there is neglible influence.
add a comment |Â
up vote
0
down vote
If you operate within specifications your choice of +ve and -ve supply rail magnitudes is not that relevant.
Usually systems are designed with same voltage but this is not a hard and fast rule. Often we see a few volts negative to handle ground references inputs and outputs and the positive supply common with other needs. Supplies of +12V and -5V would be common for reliable 0-5V operation.
Your choice of OP amp or other components will dictate the power rails.
If you need to operate at the mid point of the output swing and want to amplify ground referenced signals then you need to keep them equal magnitude.
Some new OP amps can operate very close to the rails on input and/or output. These developments are the result of the drive for ever lower operating voltages. You cannot afford to loose 1.2V of headroom if your circuit is working with a 3V supply that you want to run from a single cell that is partially depleted.
Most OP amps with single and dual rail operating specifications are inherently designed to handle uneven supplies. One of them is by design specified to be zero. Bypass, compensation and other circuitry has to be referenced to the correct point, often the negative rail so it works in both configurations.
add a comment |Â
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
11
down vote
If your op-amp can swing within 2.2V of the positive rail and within 1.8V of the negative rail under all possible load conditions, and if the inputs likewise are within the allowable common mode range then there is no problem.
There is no requirement for balanced voltages. You can use -0.1V and +20V if that works as indicated above (and, of course, if the op-amp can handle a 20.1V supply).
add a comment |Â
up vote
11
down vote
If your op-amp can swing within 2.2V of the positive rail and within 1.8V of the negative rail under all possible load conditions, and if the inputs likewise are within the allowable common mode range then there is no problem.
There is no requirement for balanced voltages. You can use -0.1V and +20V if that works as indicated above (and, of course, if the op-amp can handle a 20.1V supply).
add a comment |Â
up vote
11
down vote
up vote
11
down vote
If your op-amp can swing within 2.2V of the positive rail and within 1.8V of the negative rail under all possible load conditions, and if the inputs likewise are within the allowable common mode range then there is no problem.
There is no requirement for balanced voltages. You can use -0.1V and +20V if that works as indicated above (and, of course, if the op-amp can handle a 20.1V supply).
If your op-amp can swing within 2.2V of the positive rail and within 1.8V of the negative rail under all possible load conditions, and if the inputs likewise are within the allowable common mode range then there is no problem.
There is no requirement for balanced voltages. You can use -0.1V and +20V if that works as indicated above (and, of course, if the op-amp can handle a 20.1V supply).
answered Aug 16 at 19:33
Spehro Pefhany
195k4139388
195k4139388
add a comment |Â
add a comment |Â
up vote
0
down vote
The PSRR specs include DC meaning , other than saturation near the rails, if bipolar outputs , there is neglible influence.
add a comment |Â
up vote
0
down vote
The PSRR specs include DC meaning , other than saturation near the rails, if bipolar outputs , there is neglible influence.
add a comment |Â
up vote
0
down vote
up vote
0
down vote
The PSRR specs include DC meaning , other than saturation near the rails, if bipolar outputs , there is neglible influence.
The PSRR specs include DC meaning , other than saturation near the rails, if bipolar outputs , there is neglible influence.
answered Aug 17 at 22:36
Tony EE rocketscientist
58k22085
58k22085
add a comment |Â
add a comment |Â
up vote
0
down vote
If you operate within specifications your choice of +ve and -ve supply rail magnitudes is not that relevant.
Usually systems are designed with same voltage but this is not a hard and fast rule. Often we see a few volts negative to handle ground references inputs and outputs and the positive supply common with other needs. Supplies of +12V and -5V would be common for reliable 0-5V operation.
Your choice of OP amp or other components will dictate the power rails.
If you need to operate at the mid point of the output swing and want to amplify ground referenced signals then you need to keep them equal magnitude.
Some new OP amps can operate very close to the rails on input and/or output. These developments are the result of the drive for ever lower operating voltages. You cannot afford to loose 1.2V of headroom if your circuit is working with a 3V supply that you want to run from a single cell that is partially depleted.
Most OP amps with single and dual rail operating specifications are inherently designed to handle uneven supplies. One of them is by design specified to be zero. Bypass, compensation and other circuitry has to be referenced to the correct point, often the negative rail so it works in both configurations.
add a comment |Â
up vote
0
down vote
If you operate within specifications your choice of +ve and -ve supply rail magnitudes is not that relevant.
Usually systems are designed with same voltage but this is not a hard and fast rule. Often we see a few volts negative to handle ground references inputs and outputs and the positive supply common with other needs. Supplies of +12V and -5V would be common for reliable 0-5V operation.
Your choice of OP amp or other components will dictate the power rails.
If you need to operate at the mid point of the output swing and want to amplify ground referenced signals then you need to keep them equal magnitude.
Some new OP amps can operate very close to the rails on input and/or output. These developments are the result of the drive for ever lower operating voltages. You cannot afford to loose 1.2V of headroom if your circuit is working with a 3V supply that you want to run from a single cell that is partially depleted.
Most OP amps with single and dual rail operating specifications are inherently designed to handle uneven supplies. One of them is by design specified to be zero. Bypass, compensation and other circuitry has to be referenced to the correct point, often the negative rail so it works in both configurations.
add a comment |Â
up vote
0
down vote
up vote
0
down vote
If you operate within specifications your choice of +ve and -ve supply rail magnitudes is not that relevant.
Usually systems are designed with same voltage but this is not a hard and fast rule. Often we see a few volts negative to handle ground references inputs and outputs and the positive supply common with other needs. Supplies of +12V and -5V would be common for reliable 0-5V operation.
Your choice of OP amp or other components will dictate the power rails.
If you need to operate at the mid point of the output swing and want to amplify ground referenced signals then you need to keep them equal magnitude.
Some new OP amps can operate very close to the rails on input and/or output. These developments are the result of the drive for ever lower operating voltages. You cannot afford to loose 1.2V of headroom if your circuit is working with a 3V supply that you want to run from a single cell that is partially depleted.
Most OP amps with single and dual rail operating specifications are inherently designed to handle uneven supplies. One of them is by design specified to be zero. Bypass, compensation and other circuitry has to be referenced to the correct point, often the negative rail so it works in both configurations.
If you operate within specifications your choice of +ve and -ve supply rail magnitudes is not that relevant.
Usually systems are designed with same voltage but this is not a hard and fast rule. Often we see a few volts negative to handle ground references inputs and outputs and the positive supply common with other needs. Supplies of +12V and -5V would be common for reliable 0-5V operation.
Your choice of OP amp or other components will dictate the power rails.
If you need to operate at the mid point of the output swing and want to amplify ground referenced signals then you need to keep them equal magnitude.
Some new OP amps can operate very close to the rails on input and/or output. These developments are the result of the drive for ever lower operating voltages. You cannot afford to loose 1.2V of headroom if your circuit is working with a 3V supply that you want to run from a single cell that is partially depleted.
Most OP amps with single and dual rail operating specifications are inherently designed to handle uneven supplies. One of them is by design specified to be zero. Bypass, compensation and other circuitry has to be referenced to the correct point, often the negative rail so it works in both configurations.
answered Aug 18 at 18:39
KalleMP
3,441830
3,441830
add a comment |Â
add a comment |Â
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The main problem is that you need +/-10V, but you have +/-12V
â Eugene Sh.
Aug 16 at 19:12
I will be limiting that in software, so shouldn't be a problem
â 19172281
Aug 16 at 19:13
1
You need to provide more information about what you are trying to do.
â Eugene Sh.
Aug 16 at 19:14
1
Op-amp is being used as a differential amplifier, with a voltage reference on one input, and a DAC output on the other, which should produce a -10v to 10v swing. The DAC output will be limited to ensure the voltage doesn't exceed +/10v.
â 19172281
Aug 16 at 19:17