SIGI44
Junior Member level 1
Hello,
I would like use OpAmp to connect the test rig of an home made Vector Impedance Analyzer to channel 1 and 2 of the
oscilloscope.
I could use the 1:10 probe but this mean I loose a lot of signal (and I have a relatively low impedance).I can't use the 1:1 probe because of the poor impedance. The frequency range I'm interested is from Dc to 20 Mhz.
Pratically I would like to get an OpAmp with gain 1 , input impedance in the range minimum 10 Mohm to max TeraOhm , output
impedance in the range 10 to 200 Ohm.
First I've tried with an AD 8033 (Analog Devices):good imput impedance, good output impedance but the required gain 1
decreases over 1 Mhz and over 1 Mhz the output signal distorsion is unaceptable.
Now I'm planning to try with a ADA4817 (Analog Device). By the way I have access to ORCAD Pspice 16 (thank Sergio), but
unfortunately Analog Device on the Model for Pspice tell " distortion is not characterized ", so : no simulation.
Thank you in advance for any help by telling me if the ADA4817 is the right one, or by suggesting me another OpAmp with
the required performance (better if the Spice model contain the distorsion characterization).
Giovanni Siccardi
Imperia Italy
sigi@uno.it
I would like use OpAmp to connect the test rig of an home made Vector Impedance Analyzer to channel 1 and 2 of the
oscilloscope.
I could use the 1:10 probe but this mean I loose a lot of signal (and I have a relatively low impedance).I can't use the 1:1 probe because of the poor impedance. The frequency range I'm interested is from Dc to 20 Mhz.
Pratically I would like to get an OpAmp with gain 1 , input impedance in the range minimum 10 Mohm to max TeraOhm , output
impedance in the range 10 to 200 Ohm.
First I've tried with an AD 8033 (Analog Devices):good imput impedance, good output impedance but the required gain 1
decreases over 1 Mhz and over 1 Mhz the output signal distorsion is unaceptable.
Now I'm planning to try with a ADA4817 (Analog Device). By the way I have access to ORCAD Pspice 16 (thank Sergio), but
unfortunately Analog Device on the Model for Pspice tell " distortion is not characterized ", so : no simulation.
Thank you in advance for any help by telling me if the ADA4817 is the right one, or by suggesting me another OpAmp with
the required performance (better if the Spice model contain the distorsion characterization).
Giovanni Siccardi
Imperia Italy
sigi@uno.it
