Apple Inc.
Configurable AC/DC Sensor Readout Architecture

Abstract:

A configurable AC/DC readout architecture that can be operated in an AC measurement mode or a DC measurement mode is disclosed. The configurable AC/DC architecture can utilize shared circuitry such as amplifiers and analog-to-digital converters (ADCs). The configurable AC/DC readout can be used other sensor configurations where both AC and DC measurement signals can captured and require readout and conversion to digital signals. The configurable AC/DC readout architecture can include a filter configured to filter out a DC signal component in the AC measurement mode. The configurable AC/DC readout architecture can include a bypass witch to bypass the filter in the DC measurement mode. A programmable gain amplifier can adjust the signal amplitude of DC or AC signals to allow use of a shared analog-to-digital converter.