| Autor: |
Lee SY, Hsieh YT, Lee HY, Chang SS, Chen JY |
| Jazyk: |
angličtina |
| Zdroj: |
IEEE transactions on biomedical circuits and systems [IEEE Trans Biomed Circuits Syst] 2024 Apr; Vol. 18 (2), pp. 288-298. Date of Electronic Publication: 2024 Apr 01. |
| DOI: |
10.1109/TBCAS.2023.3322901 |
| Abstrakt: |
A second-order voltage-controlled oscillator (VCO)-based continuous-time sigma-delta modulator (CTSDM) for current-sensing readout applications is proposed. Current signals from the sensor can directly be quantized by the proposed VCO-based CTSDM, which does not require any extra trans-impedance amplifiers. With the proportional-integral (PI) structure and a VCO phase integrator, the capability of second-order noise shaping is available to reduce the in-band quantization noise. The PI structure can be simply realized by a resistor in series with the integrating capacitor, which can reduce the architecture complexity and maintain the stability of the system. The current-steering digital-to-analog converter with tail and sink current sources is used on the feedback path for the subtraction of the current-type input signal. All the components of the circuit are scaling friendly and applicable to current-sensing readout applications in the Internet of Things (IoT). The proposed VCO-based CTSDM implemented in a 0.18-μm standard CMOS process has a measured signal-to-noise and distortion ratio (SNDR) of 74.6 dB at 10 kHz bandwidth and consumes 44.8 μw only under a supply voltage of 1.2 V, which can achieve a Figure-of-Merit (FoM) of 160.76 dB. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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