Skip to main content
Knowledgebase
Home
Renesas India - Knowledgebase

How can I judge the characteristics of an operational amplifier?

Latest Updated:12/01/2011

Question:

How can I judge the characteristics of an operational amplifier?

Answer:

You can judge the characteristics of an operational amplifier using the following three parameters.

  • Gain-bandwidth product (GBP)
  • Zero-cross frequency
  • Slew rate

Operational amplifiers in which these ratings are high are faster and have wider bandwidths. However, it is important to choose an operational amplifier based on the frequency of the signals to be processed. If these parameters are not described in the electrical specifications table, use the following three graphs (showing the characteristics curves) to judge them.



This graph shows the relationship between the differential gain and frequency in an operational amplifier. The gain is high in the low-frequency area from DC, and low in the high-frequency area (the shaded area indicates the range permitted when designing a device).



This graph shows the maximum frequency (sine wave) at which a signal can be oscillated without the output being distorted (the shaded area indicates the range permitted when designing a device).



This graph shows the output response characteristics with respect to the pulse input.

Suitable Products
Operational Amplifiers
USB2.0 Host/Peripheral Controller
UPD720150