A Flexible Charge-Balanced Ratiometric Open-Loop Readout System for Capacitive Inertial Sensors

This brief presents an open-loop readout circuit for capacitive accelerometers. It combines a ratiometric approach with charge balancing for high linearity. The charge balance is implemented with a delta-sigma loop that acts as an analog-to-digital converter for a readout signal. The system avoids the low-signal-tone power levels present in current charge-balanced implementations, making it a flexible readout technique for accelerometers with varying sensitivities and dynamic ranges.