Precision Op Amps
Walt Kester and Walt Jung
This section examines in more detail some of the issues relating to amplifiers for use in precision signal conditioning applications. Although the OP177 op amp is used for the “gold standard” for precision in these discussions, more recent product introductions such as the rail-to-rail output OP777, OP727, and OP747, along with the OP1177, OP2177, and OP4177 offer nearly as good performance in smaller packages.
Precision op amp open-loop gains greater than 1 million are available, along with common-mode and power supply rejection ratios of the same magnitude. Offset voltages of less than 25 μV and offset drift less than 0.1 μV/°C are available in dual supply op amps such as the OP177, ...