Hi,
I need help in designing a voltage amplifier. My input signal is a few mili volts, around 1 MHz, and i need a gain of at least 40db.
I tried some circuits but nothing worked well...
I will Appreciate any help....circuits, PSpice files or any other ideas...
Thanks, Aviad.
check the Gain Bandwidth product of your opamp(in the datasheet). not every opamp can give you 40db at 1 MHz. you are going to need a very high frequency opamp.
As the AD8042 has a gain of app. 40 dB at 1 MHz, this is not sufficient for a closed loop gain of app. 40 dB.
Try to use an opamp which has at least 500 MHz GBW. This opamp needs not to be compensated. What about a current feedback amp ?
Thank's for the reply.
1) Are you femilier with such a opamp? With a BW of 500 MHz?
2) Can you send me a link/ add a scheme/ describe this kind of current feedback amplifier circuit?
There are many opamps resp. current-feedback amps (CFA) which have high frequency capability; for example the AD8001 has a unity gain frequency of app. 800 MHz.
This is a CFA which can be used like a non-inverting opamp circuit - provided you select the feedback resistor as recommended by the mnufacturer (data sheet).