Sense/drive architecture for CMOS-MEMS accelerometers with relaxation oscillator and TDC
- Resource Type
- Conference
- Authors
- Michalik, Piotr; Madrenas, Jordi; Fernandez, Daniel
- Source
- 2012 19th IEEE International Conference on Electronics, Circuits, and Systems (ICECS 2012) Electronics, Circuits and Systems (ICECS), 2012 19th IEEE International Conference on. :937-940 Dec, 2012
- Subject
- Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
Demodulation
Electrostatic actuators
Accelerometers
Adaptive control
Micromechanical devices
Current measurement
Mechanical variables measurement
Accelerometer
CMOS-MEMS
Surface Micro-machining
Inertial Sensor
Relaxation Oscillator
Tapped Delay Line
Time-to-Digital Converter
TDC
- Language
This paper reports a mixed-signal architecture for capacitive accelerometers conditioning based on capacitance ratio to frequency conversion and high-precision digital frequency demodulation with coarse-fine time-to-digital converter (TDC) and delay-locked loop (DLL). Furthermore, the front-end has a capability to apply pulse-controlled electrostatic actuation which can be used for the accelerometer self-test or for closed-loop operation if an external digital feedback controller is added. Since the design is dominated by standard digital circuitry, the presented concept allows rapid prototyping, what is especially important in case of microsensors monolithically integrated in advanced CMOS processes where classic analog circuits are difficult to scale-down.