Christian Steffen Birk

A 60V capacitive gain 27nV/√Hz 137dB CMRR PGA with ±10V inputs

This paper describes the implementation of a 60V programmable-gain amplifier (PGA) with ±10V differential input range and a 5V output compatible with many commercially available ADCs. While there is a wide range of possible applications, this design is particularly well suited for ±24V supply industrial process control applications, where small voltage signals need to be acquired in the presence of very large common-mode voltages.

5.7 A 19nV/√Hz-noise 2µV-offset 75µA low-drift capacitive-gain amplifier with switched-capacitor ADC driving capability

This paper describes a capacitive programmable-gain amplifier (CGA) with amplifier common-mode sampling (CMS) and switched-capacitor driving capability, compatible with many conventional switched-capacitor ADC inputs (SCAI) such as delta-sigma modulators or SAR ADCs. CGAs are popular for their low power, low noise and high precision [1,2]. The capacitive gain network is highly linear, does not dissipate static power and can be noiseless. Capacitors have excellent matching and temperature drift, which has a positive impact on offset/gain errors and their drift. They also offer a high input impedance at low frequencies and rail-to-rail operation, which makes them very suitable to interface with different types of sensors.