A Digital-Analog Hybrid System-on-Chip for Capacitive Sensor Measurement and Control

Area of Science:

• Microelectronic Engineering
• Sensor Technology
• Embedded Systems

Background:

• Capacitance-based sensors are crucial for inertial measurement, offering miniaturization and low power potential.
• Existing control and processing systems for these sensors often lack integration and efficiency.

Purpose of the Study:

• To design and implement a novel digital-analog hybrid system-on-chip (SoC) for controlling and processing capacitance-based inertial sensors.
• To achieve efficient on-chip signal processing using a dedicated least mean square error demodulation (LMSD) algorithm.

Main Methods:

• Integration of a capacitor-to-voltage (C/V) conversion circuit and a band-pass sigma-delta modulator (BPSDM) as the analog-to-digital converter (ADC).
• On-chip digital signal processing utilizing a least mean square error demodulation (LMSD) algorithm.
• Incorporation of a low-power Cortex-M3 processor for control algorithms and parameter configuration.

Main Results:

• Successful tape-out of the SoC using SMIC 180 nm CMOS technology.
• Achieved a maximum operating frequency of 105 MHz with a total chip area of 77.43 mm².
• Demonstrated low power consumption: 18 mW static and 54 mW dynamic at a 51.2 MHz system clock.

Conclusions:

• The developed hybrid SoC effectively controls and processes capacitance-based inertial sensors.
• The integrated design offers a promising solution for high-performance, low-power inertial measurement applications.
• The chip's performance metrics validate its suitability for miniaturized inertial measurement systems.