Description
This reference design explains the theory, design and testing of a high-performance signal chain for DC measurements. The main target application is digital multimeters (DMMs), however the design can also be applicable to other applications, such as data acquisition (DAQ) and condition monitoring. This design achieves high-DC accuracy using a high-performance 24-bit analog-to-digital converter, ADS127L21 and a low-noise programmable gain amplifier, PGA855, with a typical nonlinearity of ±2.4ppm and low drift over temperature. These devices are highly integrated, simplifying the overall signal chain design.
Features
Excellent DC performance, enabling high accuracyHighly-integrated components, simplifying signal chain designWide input range due to the input programmable gain filter