An Adaptative Ratio-Metric Analog-To-Digital Interface For Weakly-Coupled Resonant Sensors Based On Mutually Injection-Locked Oscillators
- Resource Type
- Conference
- Authors
- Mostafa, Ali; Juillard, Jerome; Raposo, Joao R.; Ferreira, Pietro M.
- Source
- 2019 Symposium on Design, Test, Integration & Packaging of MEMS and MOEMS (DTIP) Design, Test, Integration & Packaging of MEMS and MOEMS (DTIP), 2019 Symposium on. :1-4 May, 2019
- Subject
- Components, Circuits, Devices and Systems
weakly-coupled resonators
amplitude demodulation
ratio-metric measurement
delta-sigma modulation
- Language
In this paper, we propose a new ratio-metric interface for amplitude-modulated MEMS sensors based on mutually injection-locked oscillators (MILO). The two outputs are down-converted by a peak demodulator to improve the immunity to phase variation and noise. The peak values are then fed into a second-order discrete-time delta-sigma modulator that directly produces a digital ratio-metric output with a worst-case resolution greater than 16 bits and with input full scale of 0.6. The interface is clocked by the resonators output signal and is adapted for a sampling frequency up to 1MHz.