A Capacitance-to-Digital Converter Based on a Ring Oscillator with Flicker Noise Reduction
- Resource Type
- Conference
- Authors
- Quintero, Andres; Cardes, Fernando; Hernandez, Luis; Buffa, Cesare; Wiesbauer, Andreas
- Source
- 2016 Austrochip Workshop on Microelectronics (Austrochip) AUSTROCHIP Microelectronics (Austrochip), 2016 Austrochip Workshop on. :40-44 Oct, 2016
- Subject
- Components, Circuits, Devices and Systems
Oscillators
Micromechanical devices
Frequency modulation
Capacitors
1f noise
Sensors
Capacitance
Sigma-Delta Modulation
VCO-ADC
MEMS
Flicker Noise
- Language
This paper presents a ring oscillator based readoutcircuit for differential capacitive MEMS. Flicker noise isreduced by modulating it to frequencies above the bandwidthof interest and then filtering. A technique equivalent tochopping in conventional switched capacitor circuits isdeveloped and applied to a single ended ring oscillatorcontrolled by the MEMS capacitance. A prototype wasdesigned in a 0.12 um CMOS process. Simulations show thatflicker noise is attenuated and Signal-to-Noise Ratio isimproved.