A Sub-aF Super-High-Resolution Capacitance-to-Digital Converter with a Bandpass ΔΣ ADC
- Resource Type
- Conference
- Authors
- Jung, Yoontae; Kweon, Soon-Jae; Jeon, Hyuntak; Lee, Jeongeun; Kim, Youngin; Oh, Sein; Koo, Jimin; Je, Minkyu
- Source
- 2023 IEEE International Symposium on Circuits and Systems (ISCAS) Circuits and Systems (ISCAS), 2023 IEEE International Symposium on. :1-4 May, 2023
- Subject
- Components, Circuits, Devices and Systems
Power, Energy and Industry Applications
Signal Processing and Analysis
Power measurement
Power supplies
Linearity
Capacitance
CMOS process
Frequency conversion
Time measurement
Capacitance-to-digital converter
gas sensor
super-high-resolution
sub-aF resolution
zetta-farad resolution
bandpass
- Language
- ISSN
- 2158-1525
A super-high-resolution capacitance-to-digital converter (CDC) capable of reaching sub-aF capacitance resolution has been proposed. The CDC employs a continuous-time (CT) low-noise capacitance-to-voltage converter (CVC) followed by a high linearity bandpass $\Delta\Sigma$ ADC $(\text{BP}-\Delta\Sigma \mathrm{M})$ without frequency demodulation. By avoiding demodulation and utilizing a narrow-band sensing technique, the proposed CDC achieves a sub-aF capacitance resolution while expanding the input capacitance range through a coarse C-DAC calibration loop. The proposed circuit has been implemented in a $0.35-\mu \mathrm{m}$ CMOS process with a 3.3 V power supply voltage. The CDC shows a capacitance resolution of 0.98 $\text{aF}_{\text{rms}}$, with a capacitance range of 3.1 pF, while consuming 4.16 mW.