Time for a trim?

Did you ever wonder what trimming means when it comes to amplifiers? Better yet, have you asked yourself why it matters?

Trimming refers to various techniques IC designers use to achieve a high level of precision. There are several techniques that can be applied either at the wafer level or on the package after assembly, but ultimately they have the same goal.

The evolution of trimming has enabled some process technologies to provide unprecedented performance. Only a decade ago, CMOS amplifiers were very good if they offered an initial offset voltage of 100uV. Today, many easily get to under 50uV thanks to trimming. However, that’s only half the story. Depending on which trim method the designer chooses, he or she may be able to enhance not just the offset but the drift over temperature as well. It’s important to understand the different methods so that an assessment can be made as to which is the best option given an application.  To help you choose the best method for your project, check out my latest article in EDN, “Pushing the envelope – Understanding the precision challenge in operational amplifiers.