Digital Foreground Self-Calibration of Capacitor Mismatch for SAR ADCs
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This paper presents foreground digital self- calibration technique for successive approximation resistor (SAR) analog to digital converters (ADCs) is proposed and verified with simulations. Recent advanced in complementary metal oxide semi-conductor (CMOS) technologies and an asynchronous switching allows SAR ADCs to be utilized in a variety of applications. In SAR ADCs, the ADC linearity is mainly limited by capacitor random variation which heavily depends on integrated circuits(IC) processes. The proposed calibration technique effectively averaged out capacitor mismatch errors by taking advantages of anti-symmetric property of mismatch errors in SAR ADCs. This calibration technique significantly reduces capacitor mismatch errors without resorting extensive computation or dedicated circuits. A 12-bit 50 MS/s ADC fabricated in a 65nm CMOS process occupies a die area of 0.12 mm2. After calibration, a signal-to-noise distortion ratio (SNDR) and spurious-free dynamic range (SFDR) are improved from 44.12 dB to 72.85 dB and 50.59dB to 96.47dB, respectively.
Abstract
This paper presents foreground digital self- calibration technique for successive approximation resistor (SAR) analog to digital converters (ADCs) is proposed and verified with simulations. Recent advanced in complementary metal oxide semi-conductor (CMOS) technologies and an asynchronous switching allows SAR ADCs to be utilized in a variety of applications. In SAR ADCs, the ADC linearity is mainly limited by capacitor random variation which heavily depends on integrated circuits(IC) processes. The proposed calibration technique effectively averaged out capacitor mismatch errors by taking advantages of anti-symmetric property of mismatch errors in SAR ADCs. This calibration technique significantly reduces capacitor mismatch errors without resorting extensive computation or dedicated circuits. A 12-bit 50 MS/s ADC fabricated in a 65nm CMOS process occupies a die area of 0.12 mm2. After calibration, a signal-to-noise distortion ratio (SNDR) and spurious-free dynamic range (SFDR) are improved from 44.12 dB to 72.85 dB and 50.59dB to 96.47dB, respectively.
참고문헌 (16)
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