High gain 20 kHz amplifier

Thread Starter

kim24

Joined Mar 15, 2019
11
how to desain amplifier circuit from 1mV to 3.3Vpp gain. the frequency 100Hz-20kHz and single power supply +12Vdc (-Vdc=0) without Voffset ??
 

danadak

Joined Mar 10, 2018
4,057
Some questions -

1) Amplifier to be AC or DC coupled ?
2) Input signal is it ground referenced AC or DC ?
3) Sensor its amplifying is it differential or single ended ? Data sheet link ?
4) Do you know what the CM environment is ? Do you need to reject commond mode voltage
at input ?
5) What is being done with amplifier output ? What is its load ?

Regards, Dana.
 

AnalogKid

Joined Aug 1, 2013
9,256
A gain of 3300 at 20 kHz is a gain-bandwidth product of 66 MHz. That's a lot. You will need at least two opamp circuits in series to achieve that.

Also, with a single 12 V power source (instead of +/-12 V sources) for the opamps, there *will* be a DC offset at the output pin of the last amplifier. Ideally it will be 1/2 the power rail, or 6 Vdc. What do you mean by "no offset"?

ak
 

Wolframore

Joined Jan 21, 2019
2,273
So you want to build a line level pre-amplifier? There are many opamp based designs out there. Consider the impedance requirements also.
 

Thread Starter

kim24

Joined Mar 15, 2019
11
Some questions -

1) Amplifier to be AC or DC coupled ?
2) Input signal is it ground referenced AC or DC ?
3) Sensor its amplifying is it differential or single ended ? Data sheet link ?
4) Do you know what the CM environment is ? Do you need to reject commond mode voltage
at input ?
5) What is being done with amplifier output ? What is its load ?

Regards, Dana.
Idk because the problem is not spesific

the problem needs is to simulate the signal output using spice, so I assume it's ac coupled.
the output is single ended.
I think the circuit will be a cascading of three amplifiers but idk how, what do you think?

So you want to build a line level pre-amplifier? There are many opamp based designs out there. Consider the impedance requirements also.
Idk because the problem is not spesific

the problem needs is to simulate the signal output using spice, so I assume it's ac coupled.
the output is single ended.
I think the circuit will be a cascading of three amplifiers but idk how, what do you think?

A gain of 3300 at 20 kHz is a gain-bandwidth product of 66 MHz. That's a lot. You will need at least two opamp circuits in series to achieve that.

Also, with a single 12 V power source (instead of +/-12 V sources) for the opamps, there *will* be a DC offset at the output pin of the last amplifier. Ideally it will be 1/2 the power rail, or 6 Vdc. What do you mean by "no offset"?

ak
Idk because the problem is not spesific

the problem needs is to simulate the signal output using spice, so I assume it's ac coupled.
the output is single ended.
I think the circuit will be a cascading of three amplifiers but idk how, what do you think?

hi

Type of filter?
There will be offset...but will it be significant? If so, the circuit will need to null the offset.

eT
Idk because the problem is not spesific

the problem needs is to simulate the signal output using spice, so I assume it's ac coupled.
the output is single ended.
I think the circuit will be a cascading of three amplifiers but idk how, what do you think?
 
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