Guan‐Ying Huang

This paper presents a low-power 10-bit 50-MS/s successive approximation register (SAR) analog-to-digital converter (ADC) that uses a monotonic capacitor switching procedure. Compared to converters that use the conventional procedure, the average switching energy and total capacitance are reduced by about 81% and 50%, respectively. In the switching procedure, the input common-mode voltage gradually converges to ground. An improved comparator diminishes the signal-dependent offset caused by the input common-mode voltage variation. The prototype was fabricated using 0.13-¿m 1P8M CMOS technology. At a 1.2-V supply and 50 MS/s, the ADC achieves an SNDR of 57.0 dB and consumes 0.826 mW, resulting in a figure of merit (FOM) of 29 fJ/conversion-step. The ADC core occupies an active area of only 195 × 265 ¿m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

This paper presents a 10 b SAR ADC with a binary-scaled error compensation technique. The prototype occupies an active area of 155 × 165 ¿m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in 65 nm CMOS. At 100 MS/S, the ADC achieves an SNDR of 59.0 dB and an SFDR of 75.6 dB, while consuming 1.13 mW from a 1.2 V supply. The FoM is 15.5 fJ/conversion-step.

This paper presents an energy efficient successive-approximation-register (SAR) analog-to-digital converter (ADC) for biomedical applications. To reduce energy consumption, a bypass window technique is used to select switching sequences to skip several conversion steps when the signal is within a predefined small window. The power consumptions of the capacitive digital-to-analog converter (DAC), latch comparator, and digital control circuit of the proposed ADC are lower than those of a conventional SAR ADC. The proposed bypass window tolerates the DAC settling error and comparator voltage offset in the first four phases and suppresses the peak DNL and INL values. A proof-of-concept prototype was fabricated in 0.18-μm 1P6M CMOS technology. At a 0.6-V supply voltage and a 200-kS/s sampling rate, the ADC achieves a signal-to-noise and distortion ratio of 57.97 dB and consumes 1.04 μW, resulting in a figure of merit of 8.03 fJ/conversion-step. The ADC core occupies an active area of only 0.082 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

This brief presents a 10-bit 30-MS/s successive-approximation-register analog-to-digital converter (ADC) that uses a power efficient switchback switching method. With respect to the monotonic switching method, the input common-mode voltage variation reduces which improves the dynamic offset and the parasitic capacitance variation of the comparator. The proposed switchback switching method does not consume any power at the first digital-to-analog converter switching, which can reduce the power consumption and design effort of the reference buffer. The prototype was fabricated in a 90-nm 1P9M CMOS technology. At 1-V supply and 30 MS/s, the ADC achieves an sequenced neighbor double reservation of 56.89 dB and consumes 0.98 mW, resulting in a figure-of-merit (FOM) of 57 fJ/conversion-step. The ADC core occupies an active area of only 190 × 525 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

This paper presents a 10-bit SAR ADC using a variable window function to reduce the unnecessary switching in DAC network. At 10-MS/s and 1-V supply, the ADC consumes only 98 μW and achieves an SNDR of 60.97 dB, resulting in an FOM of 11 fJ/Conversion-step. The prototype is fabricated in a 0.18μm CMOS technology.