INPUT IMPEDANCE

[ade77]

I have a op-amp feedback configuration.

What instrument or analysis can I use to find the input impedance of the op-amp.

Also, what instrument or analysis can I use to find the slew rate.

Thank you.

[kittmaster]

slew rate on a oscope volts per second. Z can be measured by the input current and signal voltage using ohms law

[Maxish]

okogidi,

To measure DC input impedence, just apply a DC input voltage, measure current though it and divide the two. To measure current, you can place series ammeter component or use static probe(last icon) in instrument panel

Slew rate is a large signal phenomenon so you need to push your op-amp out of linear mode using a large, fast rising input signal. Set your opamp to unity gain and apply a reasonably large input pulse voltage (2 or 3 volts will do), using clock or pulse source components and use oscilloscope to probe output voltage. The slope of the output is your slew rate.

Cheers,

[dont know]

Hi can someone tell me how to plot an input and output impedence graph against frequency for a common emitter amplifier.?

i mean what kind of analysis to i use?

Many thanks in advance!!!