scholarly journals A Low-Power Column-Parallel Gain-Adaptive Single-Slope ADC for CMOS Image Sensors

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 757
Author(s):  
Jingwei Wei ◽  
Xuan Li ◽  
Lei Sun ◽  
Dongmei Li
Keyword(s):  
Low Power ◽  
Gain Control ◽  
Image Sensors ◽  
Total Power ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Current Steering ◽  
Least Significant Bit ◽  
Ramp Generator ◽  
Cmos Image Sensors

A low-power column-parallel gain-adaptive single-slope analog-to-digital converter (ADC) for CMOS image sensors is proposed. The gain-adaptive function is realized with the proposed switched-capacitor based gain control structure in which only minor changes from the traditional single-slope ADC are required. A switched-capacitor controlled dynamic bias comparator and a flip-reduced up/down double-data-rate (DDR) counter are proposed to reduce the power consumption of the column circuits. A 12-bit current steering digital-to-analog converter (DAC) with a two-dimensional gradient error tolerant switching scheme is adopted in the ramp generator to improve the linearity of the ADC. The proposed techniques were experimentally verified in a prototype chip fabricated in the TSMC 180 nm CMOS process. A single-column ADC consumes a total power of 63.2 μ W and occupies an area of 4.48 μ m × 310 μ m. The measured differential nonlinearity (DNL) and integral nonlinearity (INL) of the ADC are −0.43/+0.46 least significant bit (LSB) and −0.84/+1.95 LSB. A 13-bit linear output is acquired in nonlinearity within 0.08% of the full scale after calibration.

Low Power CMOS Image Sensors Using Two Step Single Slope ADC With Bandwidth-Limited Comparators & Voltage Range Extended Ramp Generator for Battery-Limited Application

2020 ◽  
Vol 20 (6) ◽  
pp. 2831-2838 ◽  
Author(s):  
Himchan Park ◽  
Changzhi Yu ◽  
Hyunmook Kim ◽  
Youngtaek Roh ◽  
Jinwook Burm
Keyword(s):  
Low Power ◽  
Image Sensors ◽  
Voltage Range ◽  
Ramp Generator ◽  
Cmos Image Sensors ◽  
Low Power Cmos ◽  
Limited Application

Design and Layout of a High-Performance PWM Control Class D Amplifiers IC Systems

2012 ◽  
Vol 203 ◽  
pp. 469-473
Author(s):  
Ruei Chang Chen ◽  
Shih Fong Lee
Keyword(s):  
Low Power ◽  
High Performance ◽  
Low Voltage ◽  
Design Flow ◽  
Total Power ◽  
Cmos Process ◽  
Low Power Circuits ◽  
Class D ◽  
Total Power Consumption ◽  
Power Circuits

This paper presents the design and implementation of a novel pulse width modulation control class D amplifiers chip. With high-performance, low-voltage, low-power and small area, these circuits are employed in portable electronic systems, such as the low-power circuits, wireless communication and high-frequency circuit systems. This class D chip followed the chip implementation center advanced design flow, and then was fabricated using Taiwan Semiconductor Manufacture Company 0.35-μm 2P4M mixed-signal CMOS process. The chip supply voltage is 3.3 V which can operate at a maximum frequency of 100 MHz. The total power consumption is 2.8307 mW, and the chip area size is 1.1497×1.1497 mm2. Finally, the class D chip was tested and the experimental results are discussed. From the excellent performance of the chip verified that it can be applied to audio amplifiers, low-power circuits, etc.

scholarly journals 14.85 µW Analog Front-End for Photoplethysmography Acquisition with 142-dBΩ Gain and 64.2-pArms Noise

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 512
Author(s):  
Binghui Lin ◽  
Mohamed Atef ◽  
Guoxing Wang
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Low Noise ◽  
Total Power ◽  
Cmos Process ◽  
Control Block ◽  
Silicon Area ◽  
Front End ◽  
Analog Front End

A low-power, high-gain, and low-noise analog front-end (AFE) for wearable photoplethysmography (PPG) acquisition systems is designed and fabricated in a 0.35 μm CMOS process. A high transimpedance gain of 142 dBΩ and a low input-referred noise of only 64.2 pArms was achieved. A Sub-Hz filter was integrated using a pseudo resistor, resulting in a small silicon area. To mitigate the saturation problem caused by background light (BGL), a BGL cancellation loop and a new simple automatic gain control block are used to enhance the dynamic range and improve the linearity of the AFE. The measurement results show that a DC photocurrent component up-to-10 μA can be rejected and the PPG output swing can reach 1.42 Vpp at THD < 1%. The chip consumes a total power of 14.85 μW using a single 3.3-V power supply. In this work, the small area and efficiently integrated blocks were used to implement the PPG AFE and the silicon area is minimized to 0.8 mm × 0.8 mm.

A Low-power Extended-counting Delta-sigma ADC for CMOS Image Sensors

2019 ◽  
Vol 19 (6) ◽  
pp. 594-599
Author(s):  
Woo-Tae Kim ◽  
Byung-Geun Lee
Keyword(s):  
Low Power ◽  
Image Sensors ◽  
Delta Sigma ◽  
Cmos Image Sensors

A 10-Bit Column-Parallel Single Slope ADC Based on Two-Step TDC with Error Calibration for CMOS Image Sensors

2015 ◽  
Vol 24 (04) ◽  
pp. 1550054 ◽  
Author(s):  
Jiangtao Xu ◽  
Jing Yu ◽  
Fujun Huang ◽  
Kaiming Nie
Keyword(s):  
Analog Circuits ◽  
High Speed ◽  
Propagation Delay ◽  
Image Sensors ◽  
Time Interval ◽  
Cmos Process ◽  
Digital Converter ◽  
Cmos Image Sensors ◽  
Time Problem ◽  
The Impact

This paper presents a 10-bit column-parallel single slope analog-to-digital converter (SS ADC) with a two-step time-to-digital converter (TDC) to overcome the long conversion time problem in conventional SS ADC for high-speed CMOS image sensors (CIS). The time interval proportional to the input signal is generated by a ramp generator and a comparator, which is digitized by a two-step TDC consisting of coarse and fine conversions to achieve a high-precision time-interval measurement. To mitigate the impact of propagation delay mismatch, a calibration circuit is also proposed to calibrate the delay skew within -T/2 to T/2. The proposed ADC is designed in 0.18 μm CMOS process. The power dissipation of each column circuit is 232 μW at supply voltages of 3.3 V for the analog circuits and 1.8 V for the digital blocks. The post simulation results indicate that the ADC achieves a SNDR of 60.89 dB (9.82 ENOB) and a SFDR of 79.98 dB at a conversion rate of 2 MS/s after calibration, while the SNDR and SFDR are limited to 41.52 dB and 67.64 dB, respectively before calibration. The differential nonlinearity (DNL) and integral nonlinearity (INL) without calibration are +15.80/-15.29 LSB and +1.68/-15.34 LSB while they are reduced down to +0.75/-0.25 LSB and +0.76/-0.78 LSB with the proposed calibration.

A Low-Power Incremental Delta–Sigma ADC for CMOS Image Sensors

2016 ◽  
Vol 63 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ilseop Lee ◽  
Byoungho Kim ◽  
Byung-Geun Lee
Keyword(s):  
Low Power ◽  
Image Sensors ◽  
Delta Sigma ◽  
Cmos Image Sensors

A Low-Power Pilot-DAC Based Column Parallel 8b SAR ADC With Forward Error Correction for CMOS Image Sensors

2013 ◽  
Vol 60 (10) ◽  
pp. 2572-2583 ◽  
Author(s):  
Denis Guangyin Chen ◽  
Fang Tang ◽  
Amine Bermak
Keyword(s):  
Low Power ◽  
Error Correction ◽  
Forward Error Correction ◽  
Image Sensors ◽  
Sar Adc ◽  
Cmos Image Sensors ◽  
Forward Error

scholarly journals A Low Power Sigma-Delta Modulator with Hybrid Architecture

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5309
Author(s):  
Shengbiao An ◽  
Shuang Xia ◽  
Yue Ma ◽  
Arfan Ghani ◽  
Chan Hwang See ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Supply Voltage ◽  
Total Power ◽  
Cmos Process ◽  
Hybrid Architecture ◽  
Sigma Delta Modulator ◽  
Dynamic Comparator ◽  
Flash Adc ◽  
Total Power Consumption

Analogue-to-digital converters (ADC) using oversampling technology and the Σ-∆ modulation mechanism are widely applied in digital audio systems. This paper presents an audio modulator with high accuracy and low power consumption by using a discrete second-order feedforward structure. A 5-bit successive approximation register (SAR) quantizer is integrated into the chip, which reduces the number of comparators and the power consumption of the quantizer compared with flash ADC-type quantizers. An analogue passive adder is used to sum the input signals and it is embedded in a SAR ADC composed of a capacitor array and a dynamic comparator which has no static power consumption. To validate the design concept, the designed modulator is developed in a 180 nm CMOS process. The peak signal to noise distortion ratio (SNDR) is calculated as 106 dB and the total power consumption of the chip is recorded as 3.654 mW at the chip supply voltage of 1.8 V. The input sine wave of 0 to 25 kHz is sampled at a sampling frequency of 3.2 Ms/s. Moreover, the results achieve a 16-bit effective number of bits (ENOB) when the amplitude of the input signal is varied between 0.15 and 1.65 V. By comparing with other modulators which were realized by a 180 nm CMOS process, the proposed architecture outperforms with lower power consumption.

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