Output Resistance Parameters (ro)
What is meant by the output resistance parameter (ro)?
The output resistance parameter, ro, is defined as the dc resistance that is placed in series with the output of an ideal amplifier and the output terminal for simulation of the real device. It is expressed in units of W
This parameter is difficult to measure because when an amplifier's configured open loop it is hard to balance the inputs to cause the output to become zero (or Vcc/2 if single-supply) because of the extremly high open loop gain. When this is accomplished, a load current can be drawn from the output and the change in voltage measured. Ohms law is then used to calculate ro.
Also refer to the following related links:
Op Amp Parameter Table
Op Amp Parameter Information
These pages were extracted from Op Amps For Everyone, Chapter 11, by Bruce Carter, Ron Mancini–Editor in Chief.
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