Patent ID: 8138830

Claim:
An on-chip instrumentation amplifier for converting a differential voltage signal to a single-ended output voltage signal during testing of on-chip components, comprising: a plurality of switchable feedback paths associated with a discrete plurality of gain settings, each gain setting being defined by having (i) a negative input voltage of the differential voltage signal received at a positive input terminal of a first operational amplifier, (ii) a positive input voltage of the differential voltage signal received at a positive input terminal of a second operational amplifier, (iii) a negative input terminal of the first operational amplifier coupled via a first switch S 1 to a programmably selected one of a first node of each switchable feedback path, and (iv) a negative input terminal of the second operational amplifier coupled via a switch S 2 to a programmably selected one of a second node of each switchable feedback path, wherein each switchable feedback path has a predefined corresponding feedback resistance Rn. 1 and a corresponding shunt resistance Rn. 2 , where the values Rn. 2 for each switchable feedback path is different than that of the other switchable feedback paths.