Calculation of the Worst-Case Data Patterns and Eye Diagram for Nonlinear High-Speed Links

The equalization of a large attenuation signal and multirate communication in high-speed serial interface is hard to balance. To overcome this difficulty, an adaptive equalization system with optimized eye-opening monitor is proposed. The designed eye-opening monitor is based on the asynchronous statistic eye diagram tracking algorithm, and the eye diagram is obtained by undersampling with the low-speed asynchronous clock. With the eye-opening monitor into the adaptive loop, an adaptive equalization system combined with continuous-time linear equalization (CTLE) is completed. And the inductor peaking technology is used to improve the capacity of compensation. With SMIC 28 nm CMOS process to achieve the overall design, the power consumption and core chip area are 12 mW @ 12.5 Gbps and 0.12 mm2, respectively. And postsimulation results show that it can offer compensation from 6 to 21 dB for 1.25–12.5 Gbps range of receiving data, which achieves a large range of data rate and channel loss, and its power efficiency is 0.046 pJ/bit/dB for the worst case, which is better than most previous works.

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

Journal of Circuits System and Computers ◽

10.1142/s0218126618501165 ◽

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.

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Fast and Accurate Estimation of Statistical Eye Diagram for Nonlinear High-Speed Links

IEEE Transactions on Very Large Scale Integration (VLSI) Systems ◽

10.1109/tvlsi.2021.3082208 ◽

2021 ◽

pp. 1-9

Author(s):

Xiuqin Chu ◽

Wenting Guo ◽

Jun Wang ◽

Feng Wu ◽

Yuhuan Luo ◽

...

Keyword(s):

High Speed ◽

Accurate Estimation ◽

Eye Diagram

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High-speed PAM-4 Eye Diagram Analyzer Based on Simplified Linear Optical Sampling Technique

2020 IEEE 20th International Conference on Communication Technology (ICCT) ◽

10.1109/icct50939.2020.9295878 ◽

2020 ◽

Author(s):

Huan He ◽

Yi Wu ◽

Songnian Fu

Keyword(s):

High Speed ◽

Sampling Technique ◽

Eye Diagram ◽

Optical Sampling ◽

Linear Optical

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A 25 Gbps VCSEL driving ASIC: an attempt for ultra-high-speed front-end readout applications

Journal of Instrumentation ◽

10.1088/1748-0221/17/01/c01040 ◽

2022 ◽

Vol 17 (01) ◽

pp. C01040

Author(s):

C. Zhao ◽

D. Guo ◽

Q. Chen ◽

N. Fang ◽

Y. Gan ◽

...

Keyword(s):

High Speed ◽

Cmos Technology ◽

Test Results ◽

Eye Diagram ◽

Optical Links ◽

Optical Module ◽

Active Feedback ◽

High Bandwidth ◽

Output Driver ◽

Very High

Abstract This paper presents the design and the test results of a 25 Gbps VCSEL driving ASIC fabricated in a 55 nm CMOS technology as an attempt for the future very high-speed optical links. The VCSEL driving ASIC is composed of an input equalizer stage, a pre-driver stage and a novel output driver stage. To achieve high bandwidth, the pre-driver stage combines the inductor-shared peaking structure and the active-feedback technique. A novel output driver stage uses the pseudo differential CML driver structure and the adjustable FFE pre-emphasis technique to improve the bandwidth. This VCSEL driver has been integrated in a customized optical module with a VCSEL array. Both the electrical function and optical performance have been fully evaluated. The output optical eye diagram has passed the eye mask test at the data rate of 25 Gbps. The peak-to-peak jitter of 25 Gbps optical eye is 19.5 ps and the RMS jitter is 2.9 ps.

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Simple Measurement of Eye Diagram and BER Using High-Speed Asynchronous Sampling

Journal of Lightwave Technology ◽

10.1109/jlt.2004.827669 ◽

2004 ◽

Vol 22 (5) ◽

pp. 1296-1302 ◽

Cited By ~ 40

Author(s):

I. Shake ◽

H. Takara ◽

S. Kawanishi

Keyword(s):

High Speed ◽

Eye Diagram ◽

Asynchronous Sampling ◽

Simple Measurement

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Simultaneous switching noise impact to signal eye diagram on high-speed I/O

2012 4th Asia Symposium on Quality Electronic Design (ASQED) ◽

10.1109/acqed.2012.6320501 ◽

2012 ◽

Cited By ~ 1

Author(s):

Siang Rui Chan ◽

Fern Nee Tan ◽

Rosmiwati Mohd-Mokhtar

Keyword(s):

High Speed ◽

Switching Noise ◽

Eye Diagram ◽

Noise Impact ◽

Simultaneous Switching Noise ◽

Simultaneous Switching

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Comprehensive Sensing Current Analysis and Its Guideline for the Worst-Case Scenario of RRAM Read Operation

Electronics ◽

10.3390/electronics7100224 ◽

2018 ◽

Vol 7 (10) ◽

pp. 224 ◽

Cited By ~ 3

Author(s):

Zhensen Tang ◽

Yao Wang ◽

Yaqing Chi ◽

Liang Fang

Keyword(s):

Case Scenario ◽

Worst Case ◽

Trade Off ◽

Crossbar Array ◽

Worst Case Scenario ◽

Read Operation ◽

Shunting Effect ◽

Injection Effect ◽

Parameter Dependent ◽

Case Data

In this paper, the dependence of sensing currents on various device parameters is comprehensively studied by simulating the complete crossbar array rather than its equivalent analytical model. The worst-case scenario for read operation is strictly analyzed and defined in terms of selected location and data pattern, respectively, based on the effect of parasitic sneak paths and interconnection resistance. It is shown that the worst-case data pattern depends on the trade-off between the shunting effect of the parasitic sneak paths and the current injection effect of the parasitic sneak leakage, thus requiring specific analysis in practical simulations. In dealing with that, we propose a concept of the threshold array size incorporating the trade-off to define the parameter-dependent worst-case data pattern. This figure-of-merit provides guidelines for the worst-case scenario analysis of the crossbar array read operations.

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