Amplifier front-end with low-noise level shift

cmrefrefref refcmrefAn amplifier front-end comprises an input node for receiving a common-mode voltage V, a differential transistor pair having first and second inputs and outputs, a capacitor, a reference voltage V, an error correction circuit, and a switching network. The switching network charges the capacitor to V; couples the capacitor to the differential pair's first input and couples Vto the pair's second input such that the voltage at both inputs is ˜V; and couples the input node to the capacitor's other terminal such that the voltage at the first input is level-shifted to ˜(V+V). The error correction circuit-typically an auto-zero circuit-is coupled to the differential pair's outputs and arranged to reduce charge injection error and kT/C noise components that would otherwise be present in the outputs due to the level shift.