A 12-Bit 500-MS/s Current Steering CMOS DAC for High-Speed PLC Modems

2016 ◽  
Vol 25 (10) ◽  
pp. 1650122 ◽  
Author(s):  
Chan-Keun Kwon ◽  
Junil Moon ◽  
Soo-Won Kim
Keyword(s):  
High Speed ◽  
Dynamic Range ◽  
Supply Voltage ◽  
Design Procedure ◽  
Weighted Averaging ◽  
Total Power ◽  
Cmos Process ◽  
Current Steering ◽  
Current Cell ◽  
Total Power Consumption

A 12-bit 500-MS/s current steering digital-to-analog converter (DAC) for high-speed power line communication (PLC) modems is presented in this paper. The performance of current steering DAC is limited by the current cell mismatches and glitch problems caused by switching timing errors. In this paper, the current cell design procedure is presented to minimize random mismatches. Then, a new data-weighted averaging (DWA) technique with fewer glitches and low hardware complexity is proposed to compensate for the gradient mismatch. Spurious-free dynamic range (SFDR) improvement and low complexity are effectively achieved by employing both a row–column structure and a (CSA) structure as the floor plan of the proposed DAC. The proposed DAC is implemented in a standard 0.18-[Formula: see text]m CMOS process with an active area of 2.445[Formula: see text]mm2, which achieves a differential non linearity (DNL) of 0.25[Formula: see text]LSB and an integral non-linearity (INL) of 0.19[Formula: see text]LSB. Additionally, the SFDR increases by 13.2[Formula: see text]dB (on average) when employing the proposed DWA technique. The total power consumption of the proposed DAC is 176[Formula: see text]mW from a 1.8-V supply voltage.

A CMOS Image Sensor with a Novel Passive Pixel Array and High Precision Current Amplifier for a Compact Digital X-ray Detector

2020 ◽  
Vol 10 (11) ◽  
pp. 2745-2753
Author(s):  
Jimin Cheon ◽  
Dongmyung Lee ◽  
Hojong Choi
Keyword(s):  
High Precision ◽  
Dynamic Range ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Total Power ◽  
Cmos Process ◽  
Current Amplifier ◽  
X Ray ◽  
Total Power Consumption ◽  
Pixel Array

An active pixel sensor (APS) in a digital X-ray detector is the dominant circuitry for a CMOS image sensor (CIS) despite its lower fill factor (FF) compared to that of a passive pixel sensor (PPS). Although the PPS provides higher FF, its overall signal-to-noise ratio (SNR) is lower than that of the APS. The required high resolution and small focal plane can be achieved by reducing the number of transistors and contacts per pixel. We proposed a novel passive pixel array and a high precision current amplifier to improve the dynamic range (DR) without minimizing the sensitivity for diagnostic compact digital X-ray detector applications. The PPS can be an alternative to improve the FF. However, size reduction of the feedback capacitor causes degradation of SNR performance. This paper proposes a novel PPS based on readout and amplification circuits with a high precision current amplifier to minimize performance degradation. The expected result was attained with a 0.35-μm CMOS process parameter with power supply voltage of 3.3 V. The proposed PPS has a saturation signal of 1.5 V, dynamic range of 63.5 dB, and total power consumption of 13.47 mW. Therefore, the proposed PPS readout circuit improves the dynamic range without sacrificing the sensitivity.

A 16.4 nW, Sub-1 V, Resistor-Less Voltage Reference with BJT Voltage Divider

2018 ◽  
Vol 27 (13) ◽  
pp. 1850206 ◽  
Author(s):  
Qingshan Yang ◽  
Peiqing Han ◽  
Niansong Mei ◽  
Zhaofeng Zhang
Keyword(s):  
Low Voltage ◽  
Supply Voltage ◽  
Voltage Divider ◽  
Total Power ◽  
Cmos Process ◽  
Operating Voltage ◽  
Voltage Reference ◽  
Ultra Low Power ◽  
Silicon Area ◽  
Total Power Consumption

A 16.4[Formula: see text]nW, sub-1[Formula: see text]V voltage reference for ultra-low power low voltage applications is proposed. This design reduces the operating voltage to 0.8[Formula: see text]V by a BJT voltage divider and decreases the silicon area considerably by eliminating resistors. The PTAT and CTAT are based on SCM structures and a scaled-down [Formula: see text], respectively, to improve the process insensitivity. This work is fabricated in 0.18[Formula: see text][Formula: see text]m CMOS process with a total area of 0.0033[Formula: see text]mm2. Measured results show that it works properly for supply voltage from 0.8[Formula: see text]V to 2[Formula: see text]V. The reference voltage is 467.2[Formula: see text]mV with standard deviation ([Formula: see text]) being 12.2 mV and measured TC at best is 38.7[Formula: see text]ppm/[Formula: see text]C ranging from [Formula: see text]C to 60[Formula: see text]C. The total power consumption is 16.4[Formula: see text]nW under the minimum supply voltage at 27[Formula: see text]C.

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.

Design of a 10-Bit High Performance Current-Steering DAC with a Novel Nested Decoder Based on Domino Logic

2015 ◽  
Vol 24 (06) ◽  
pp. 1550086 ◽  
Author(s):  
Masoud Nazari ◽  
Leila Sharifi ◽  
Meysam Akbari ◽  
Omid Hashemipour
Keyword(s):  
Power Consumption ◽  
High Performance ◽  
Dynamic Range ◽  
Logic Gates ◽  
Cmos Technology ◽  
Total Power ◽  
Current Steering ◽  
Domino Logic ◽  
Chip Area ◽  
Total Power Consumption

In this paper, a 10-bit 8-2 segmented current-steering digital-to-analog converter (DAC) is presented which uses a novel nested binary to thermometer (BT) decoder based on domino logic gates. High accuracy and high performances are achieved with this structure. The proposed decoder has a pipelining scheme and it is designed symmetrically in three stages with repeatable logic gates. Thus, power consumption, chip area and the number of control signals are reduced. The proposed DAC is simulated in 0.18-μm CMOS technology and the spurious-free dynamic range (SFDR) is 65.3 dB over a 500 MHz output bandwidth at 1 GS/s. Total power consumption of the designed DAC is only 23.4 mW while the digital and analog supply voltages are 1.2 and 1.8 V, respectively. The active area of the proposed DAC is equal to 0.3 mm2.

An 8-Bit Ultra-Low-Power, Low-Voltage Current Steering DAC Utilizing a New Segmented Structure

2019 ◽  
Vol 28 (10) ◽  
pp. 1950172
Author(s):  
Mehdi Bandali ◽  
Alireza Hassanzadeh ◽  
Masoume Ghashghaie ◽  
Omid Hashemipour
Keyword(s):  
Low Power ◽  
Dynamic Range ◽  
Low Voltage ◽  
Supply Voltage ◽  
Cmos Technology ◽  
The Body ◽  
Current Steering ◽  
Ultra Low Power ◽  
Current Cell ◽  
Sample Rate

In this paper, an 8-bit ultra-low-power, low-voltage current steering digital-to-analog converter (DAC) is presented. The proposed DAC employs a new segmented structure that results in low integral nonlinearity (INL) and high spurious-free dynamic range (SFDR). Moreover, this DAC utilizes a low-voltage current cell. The low-voltage characteristic of the current cell is achieved by connecting the body of MOSFET switches to their sources. Utilizing a low supply voltage along with a low bias current in the current cells results in about 623.81-[Formula: see text]W power consumption in 140-MS/s sample rate, which is very small compared to previous reports. The post-layout simulation results in 180-nm CMOS technology and [Formula: see text]-V supply voltage with the sample rate of 140[Formula: see text]MS/s show SFDR [Formula: see text] 64.37[Formula: see text]dB in the Nyquist range. The differential nonlinearity (DNL) and INL of the presented DAC are 0.1254 LSB and 0.1491 LSB, respectively.

scholarly journals A 13-Bit, 12-ps Resolution Vernier Time-to-Digital Converter Based on Dual Delay-Rings for SPAD Image Sensor

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 743
Author(s):  
Zunkai Huang ◽  
Jinglin Huang ◽  
Li Tian ◽  
Ning Wang ◽  
Yongxin Zhu ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Single Photon ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Total Power ◽  
Cmos Process ◽  
Digital Converter ◽  
Delay Element ◽  
Time To Digital Converter ◽  
Total Power Consumption

A three-dimensional (3D) image sensor based on Single-Photon Avalanche Diode (SPAD) requires a time-to-digital converter (TDC) with a wide dynamic range and fine resolution for precise depth calculation. In this paper, we propose a novel high-performance TDC for a SPAD image sensor. In our design, we first present a pulse-width self-restricted (PWSR) delay element that is capable of providing a steady delay to improve the time precision. Meanwhile, we employ the proposed PWSR delay element to construct a pair of 16-stages vernier delay-rings to effectively enlarge the dynamic range. Moreover, we propose a compact and fast arbiter using a fully symmetric topology to enhance the robustness of the TDC. To validate the performance of the proposed TDC, a prototype 13-bit TDC has been fabricated in the standard 0.18-µm complementary metal–oxide–semiconductor (CMOS) process. The core area is about 200 µm × 180 µm and the total power consumption is nearly 1.6 mW. The proposed TDC achieves a dynamic range of 92.1 ns and a time precision of 11.25 ps. The measured worst integral nonlinearity (INL) and differential nonlinearity (DNL) are respectively 0.65 least-significant-bit (LSB) and 0.38 LSB, and both of them are less than 1 LSB. The experimental results indicate that the proposed TDC is suitable for SPAD-based 3D imaging applications.

scholarly journals A 19 MW, 12.5 B, 2.1 MS/S SINGLE-BIT DS ADC IN 0.18 MM DIGITAL CMOS PROCESS

2021 ◽  
Vol 7 (3) ◽  
pp. 31-35
Author(s):  
Mona Safi-Harb ◽  
◽  
Gordon W. Roberts ◽  
Keyword(s):  
Integrated Circuit ◽  
Communication Systems ◽  
High Speed ◽  
Dynamic Range ◽  
Supply Voltage ◽  
System Level ◽  
Portable Devices ◽  
Cmos Process ◽  
Multi Stage ◽  
Delta Sigma

The increasingly stringent requirements of today’s communication systems and portable devices are imposing two challenges on the design of high-resolution, high-speed ADCs and delta-sigma modulators (DSMs) in particular. The first is the extension of the input frequency range to include applications where the input bandwidth exceeds the 1 MHz range, while maintaining a feasible sampling frequency. The challenge in extending the operational speed of DSMs is further rendered more complicated by the ever shrinking transistor dimension, and in turn, the supply voltage, hence the second challenge. To address those two challenges, the DSMs presented in this paper targets a minimum of 12 bits in resolution at 2 MS/s Nyquist conversion rate, while using a single 1.8 V supply and minimum power dissipation.A switched-capacitor (SC) DS ADC integrated circuit (IC) with output rate slightly exceeding 2 MS/s was successfully implemented in a 1.8 V, 0.18 mm standard CMOS process. The IC consists of a fourth-order, multi-stage (2-1-1), single-bit modulator sampled at an oversampling rate of 50 MHz. Special effort has been made to reduce the power consumption of the modulator through careful system-level modeling and synthesis of circuit specifcations. Experimental results reveal a 77.6 dB dynamic range while consuming 18.8 mW of power, making it the lowest power dissipation for output rates in excess of 2 MS/s.

A High-Speed Temperature Sensor with Low Supply Sensitivity for SoC Thermal Monitoring

2018 ◽  
Vol 27 (07) ◽  
pp. 1850116
Author(s):  
Yuanxin Bao ◽  
Wenyuan Li
Keyword(s):  
Temperature Sensor ◽  
Conversion Rate ◽  
High Speed ◽  
Supply Voltage ◽  
Ring Oscillator ◽  
Temperature Sensitive ◽  
Cmos Process ◽  
Digital Code ◽  
Thermal Monitoring ◽  
Worst Case

A high-speed low-supply-sensitivity temperature sensor is presented for thermal monitoring of system on a chip (SoC). The proposed sensor transforms the temperature to complementary to absolute temperature (CTAT) frequency and then into digital code. A CTAT voltage reference supplies a temperature-sensitive ring oscillator, which enhances temperature sensitivity and conversion rate. To reduce the supply sensitivity, an operational amplifier with a unity gain for power supply is proposed. A frequency-to-digital converter with piecewise linear fitting is used to convert the frequency into the digital code corresponding to temperature and correct nonlinearity. These additional characteristics are distinct from the conventional oscillator-based temperature sensors. The sensor is fabricated in a 180[Formula: see text]nm CMOS process and occupies a small area of 0.048[Formula: see text]mm2 excluding bondpads. After a one-point calibration, the sensor achieves an inaccuracy of [Formula: see text][Formula: see text]1.5[Formula: see text]C from [Formula: see text]45[Formula: see text]C to 85[Formula: see text]C under a supply voltage of 1.4–2.4[Formula: see text]V showing a worst-case supply sensitivity of 0.5[Formula: see text]C/V. The sensor maintains a high conversion rate of 45[Formula: see text]KS/s with a fine resolution of 0.25[Formula: see text]C/LSB, which is suitable for SoC thermal monitoring. Under a supply voltage of 1.8[Formula: see text]V, the maximum energy consumption per conversion is only 7.8[Formula: see text]nJ at [Formula: see text]45[Formula: see text]C.

scholarly journals On-CMOS Image Sensor Processing for Lane Detection

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3713
Author(s):  
Soyeon Lee ◽  
Bohyeok Jeong ◽  
Keunyeol Park ◽  
Minkyu Song ◽  
Soo Youn Kim
Keyword(s):  
Edge Detection ◽  
High Speed ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Image Resolution ◽  
Lane Detection ◽  
Frame Rate ◽  
Total Power ◽  
Detection Accuracy ◽  
Total Power Consumption

This paper presents a CMOS image sensor (CIS) with built-in lane detection computing circuits for automotive applications. We propose on-CIS processing with an edge detection mask used in the readout circuit of the conventional CIS structure for high-speed lane detection. Furthermore, the edge detection mask can detect the edges of slanting lanes to improve accuracy. A prototype of the proposed CIS was fabricated using a 110 nm CIS process. It has an image resolution of 160 (H) × 120 (V) and a frame rate of 113, and it occupies an area of 5900 μm × 5240 μm. A comparison of its lane detection accuracy with that of existing edge detection algorithms shows that it achieves an acceptable accuracy. Moreover, the total power consumption of the proposed CIS is 9.7 mW at pixel, analog, and digital supply voltages of 3.3, 3.3, and 1.5 V, respectively.

SFDR Improvement Algorithms for Current-Steering DACs

2015 ◽  
Vol 643 ◽  
pp. 101-108 ◽  
Author(s):  
Shaiful Nizam Mohyar ◽  
Masahiro Murakami ◽  
Atsushi Motozawa ◽  
Haruo Kobayashi ◽  
Osamu Kobayashi ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Current Source ◽  
Weighted Averaging ◽  
Current Steering ◽  
Switching Sequence ◽  
Digital To Analog Converters ◽  
Compensation Methods ◽  
Spurious Free Dynamic Range ◽  
Data Weighted Averaging ◽  
Combined Algorithm

This paper presents algorithms for improving spurious-free dynamic range (SFDR) of current-steering digital-to-analog converters (DACs) — targeted at communication applications — by minimizing both current-source mismatches and glitches. Conventional segmented current-steering DACs suffer from static mismatches among current sources which cause nonlinearity and degrade SFDR, though glitch energy is relatively small. The data-weighted averaging (DWA) algorithm can reduce static current source mismatch effects, but it increases the effects of glitch energy. Here we investigate the use of both conventional Switching-Sequence Post-Adjustment (SSPA) calibration and One–Element-Shifting (OES) methods in order to reduce the effects of both nonlinearity and glitch energy. For further improvement, we propose and investigate a fully-digital combined algorithm to reduce static current source mismatch effects with minimal increase in the glitch energy. We also did simulations of the effect of combining these two compensation methods. Our MATLAB simulations show that the combined algorithm can improve SFDR performance by 24 dB, 22dB and 2dB compared to conventional thermometer-coded, one-element-shifting and SSPA methods respectively in some conditions. When we take current mismatch into account, the combined algorithm causes glitch energy to increase by only 0.02 to 0.2 % compared to the other three methods alone.

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