학술논문

A VCO Linearization Technique Using Dual-VCO and Interpolation for Time-Based ADCs
Document Type
Conference
Source
2023 IEEE 66th International Midwest Symposium on Circuits and Systems (MWSCAS) Circuits and Systems (MWSCAS), 2023 IEEE 66th International Midwest Symposium on. :996-1000 Aug, 2023
Subject
Components, Circuits, Devices and Systems
Interpolation
Quantization (signal)
Voltage-controlled oscillators
Linearization techniques
Linearity
Voltage
Topology
VCO-based ADC
linearization
time-to-digital converter (TDC)
calibration
ring oscillator
interpolation
Language
ISSN
1558-3899
Abstract
A VCO linearization technique for time-based ADCs increases the input range by interpolating the VCO's V-F transfer characteristic. Utilizing a dual-VCO and exploiting the intrinsic expansive and compressive regions of the transfer characteristic, the proposed technique reduces the nonlinearity after quantization in the digital domain. A detailed study reveals the optimal regions of operation and contrasts the linearity with that from the conventional single-VCO topology. Simulations show the proposed technique increases the input amplitude to 120% of the supply voltage and improves the ADC SNDR by 30.6 dB and SFDR by 32.7dB compared to the conventional design.