Part Number Search

Cross Reference Search

About information presented in this cross reference

The information presented in this cross reference is based on TOSHIBA's selection criteria and should be treated as a suggestion only. Please carefully review the latest versions of all relevant information on the TOSHIBA products, including without limitation data sheets and validate all operating parameters of the TOSHIBA products to ensure that the suggested TOSHIBA products are truly compatible with your design and application.
Please note that this cross reference is based on TOSHIBA's estimate of compatibility with other manufacturers' products, based on other manufacturers' published data, at the time the data was collected.
TOSHIBA is not responsible for any incorrect or incomplete information. Information is subject to change at any time without notice.

Keyword Search

Parametric Search

Stock Check & Purchase

Select Product Categories

Characteristics of op-amps (What is the ideal op-amp?)

What is the ideal op-amp?

Generally, it is desirable that amplifiers neither affect the preceding circuit nor be affected by the subsequent circuit.
Therefore, amplifiers should have high input impedance and low output impedance.
Op-amps have characteristics close to these requirements. The following compares the ideal and real op-amps:

Although there is no such thing as an ideal op-amp, you can assume the ideal op-amp early in the design stage.
However, you should consider the differences between the ideal and real op-amps when you proceed to the detailed design stage.
For example, if the input impedance of an op-amp is low, its input voltage is derived from the input impedance of that op-amp and the output impedance of the preceding device. The low input impedance of an op-amp also affects its feedback loop.
If the output impedance of an op-amp is not zero, its output voltage is derived from the output impedance of that op-amp and the impedance of its load.

In typical applications, however, the input impedance of an op-amp is negligibly large compared with the input impedance of the preceding circuit, and the output impedance is negligibly small compared with the impedance of the subsequent load. Therefore, these impedances usually do not have a significant impact. The same is true of the other parameters shown above.
Take their impacts into consideration when creating a detailed design.

A new window will open