Hi All,
I would like to choose an op amp that will be configured as a trans-impedance amplifier. A 5V source is driving a variable resistance, from 20KOhm down to 500Ohm, at up to 100kHz (voltage frequency, not resistance changes). Furthermore, it is very important that the voltage at the noninverting input is as close to zero volts as possible, say in the nanovolts range (the virtual ground is essential for circuit stability).
To this end I have been looking at op amps with an inherently low input offset voltage, and also perhaps those with the ability to trim said voltage. Will manually trimming the offset voltage load the input in any way (its very important that I can precisely calculate the variable resistors resistance)?
In the end I need some advice on choosing an amplifier because there are countless op amps to choose from and I'm not particularly experienced!
Cheers
EDIT: It's for a PCB implementation, hand soldered and hot air gun, so a surface mount where the pins can be accessed is ideal
I would like to choose an op amp that will be configured as a trans-impedance amplifier. A 5V source is driving a variable resistance, from 20KOhm down to 500Ohm, at up to 100kHz (voltage frequency, not resistance changes). Furthermore, it is very important that the voltage at the noninverting input is as close to zero volts as possible, say in the nanovolts range (the virtual ground is essential for circuit stability).
To this end I have been looking at op amps with an inherently low input offset voltage, and also perhaps those with the ability to trim said voltage. Will manually trimming the offset voltage load the input in any way (its very important that I can precisely calculate the variable resistors resistance)?
In the end I need some advice on choosing an amplifier because there are countless op amps to choose from and I'm not particularly experienced!
Cheers
EDIT: It's for a PCB implementation, hand soldered and hot air gun, so a surface mount where the pins can be accessed is ideal
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