| 摘要 |
An amplifier front-end comprises an input node for receiving a common-mode voltage Vcm, a differential transistor pair having first and second inputs and outputs, a capacitor, a reference voltage Vref, an error correction circuit, and a switching network. The switching network charges the capacitor to Vref; couples the capacitor to the differential pair's first input and couples Vref to the pair's second input such that the voltage at both inputs is ~Vref; and couples the input node to the capacitor's other terminal such that the voltage at the first input is level-shifted to ~(Vcm+Vref). 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.
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