• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.115-119
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• 2022

A readout circuit for a mercury-cadmium-telluride (MCT)-amplified mid-wave infrared (IR) photodetector was realized and applied to noncontact chemical agent detectors based on a quantum cascade laser (QCL). The QCL emitted 250 times for each wavelength in 0.2-㎛ steps from 8 to 12 ㎛ with a frequency of 100 kHz and duty ratio of 10%. Because of the nonconstant QCL emission power during on-duty, averaging the photodetector signals is essential. Averaging can be performed in digital back-end processing through a high-speed analog-to-digital converter (ADC) or in analog front-end processing through an integrator circuit. In addition, it should be considered that the 250 IR data points should be completely transferred to a PC during each wavelength tuning period of the QCL. To average and minimize the IR data, we designed a readout circuit using the analog front-end processing method. The proposed readout circuit consisted of a switched-capacitor integrator, voltage level shifter, relatively low-speed analog-to-digital converter, and micro-control unit. We confirmed that the MCT photodetector signal according to the QCL source can be accurately read and transferred to the PC without omissions.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.57-60
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• 2001

A readout circuit for Dual band IR detector was proposed and designed. Designed circuit provide to detector a stable diode bias and high injection efficiency using Buffered Direct Injection (BDI) input circuit. Then, amplifier in the unit cell is operated when cell is selected in order to minimize the power consumption. We could confirm through the simulation that designed circuit integrate and output simultaneously the signal generating from the dual band IR detector.

• Journal of the Semiconductor & Display Technology
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• v.6 no.2 s.19
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• pp.49-52
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• 2007

Characteristics of an active pixel switch readout circuit were studied by SPICE simulation. A simple readout circuit consists of an operation amplifier, a diode, and a down-counter was suggested, and its successful operation was verified by showing that the differences in the detected signal intensity are accordingly converted to modulation of the voltage pulses generated by the comparator. A scheme to use these pulses to generate the original image was also put forward.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.48-52
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• 2005

The research topic of super-RENS technology is shifting from the signal intensity (CNR; Carrier to Noise Ratio) to the signal uniformity (Jitter or bER). To achieve an uniform signal characteristics, it is important to reduce signal fluctuation in a super-RENS disc. In this study, we investigated the relation between signal fluctuation and low frequency noise (LFN), and analyzed LFN increase in recording and readout processes. It was found that signal fluctuation had a close relationship with the LFN. Also, it was found that the recorded mark shape such a bubble type and high readout power increased the LFN in recording and readout process of a super-RENS disc. So, using non-bubble type recording material and low super-resolution readout material, we markedly improved the LFN in a super-RENS disc.

• Journal of Semiconductor Engineering
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• v.1 no.3
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• pp.81-87
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• 2020

An instrumentation amplifier (IA) and an analog-to-digital converter (ADC) are essential circuit blocks for accurate and robust sensor readout systems. This paper introduces recent advances in radiation-hardening by design (RHBD) techniques applied for the sensor readout integrated circuits (IC), e.g., the three-op-amp IA and the successive-approximation register (SAR) ADC, operating against total ionizing dose (TID) and singe event effect (SEE) in harsh radiation environments. The radiation-hardened IA utilized TID monitoring and adaptive reference control to compensate for transistor parameter variations due to radiation effects. The radiation-hardened SAR ADC adopts delay-based double-feedback flip-flops to prevent soft errors which flips the data bits. Radiation-hardened IA and ADC were verified through compact model simulation, and fabricated CMOS chips were measured in radiation facilities to confirm their radiation tolerance.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.793-799
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• 2016

A multi-purpose sensor interface that provides dual-mode operation of fingerprint sensing and physiological signal detection is presented. The dual-mode sensing capability is achieved by utilizing inter-pixel shielding patterns as capacitive amplifier's input electrodes. A prototype readout circuit including a fingerprint panel for feasibility verification was fabricated in a $0.18{\mu}m$ CMOS process. A single-channel readout circuit was implemented and multiplexed to scan two-dimensional fingerprint pixels, where adaptive calibration capability against pixel-capacitance variations was also implemented. Feasibility of the proposed multi-purpose interface was experimentally verified keeping low-power consumption less than 1.9 mW under a 3.3 V supply.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.48-55
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• 2016

Ambient-light sensor system, which changes the brightness of a display as ambient light change, was studied to reduce the power consumption of the mobile applications such as note PC, tablet PC and smart phone. The ambient-light sensor system should be integrated on a display panel to improve the complexity and cost of mobile applications, so the ambient-light sensor and readout circuit was integrated on a display panel using low-temperature poly-silicon thin film transistors (LTPS-TFT). We proposed the new compensation method to correct the panel-to-panel variation of the ambient-light sensors, without additional equipment. We designed and investigated the new readout circuit with the proposed compensation method and the analog-to-digital converter for the final digital output of ambient light. The readout circuit has very simple structure and control timing to be integrated with LTPS-TFT, and the input luminance ranges from 10 to 10,000 lux. The readout rate is 100 Hz, and maximum differential non-uniformity with 20 levels of the final output below 0.5 LSB.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.4
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• pp.33-38
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• 2001

Readout signal of high density DVD-RAM disk output was simulated to analyze the effect of crosserase and crosstalk to the readout signal which is one of the main difficulties to realize high density DVD-RAM system having single side recording density of 4.7 G13 and 15 G13 media. Laser beam intensity impinged on the disk was approximated as Gaussian and recorded marks were assumed elliptical and the readout signal was calculated as a two dimensional convolution of laser beam pattern and recored mark pattern. From the readout signal obtained by varying crosserase ratio, carrier levels with period of 3T to 11 T were calculated and compared. Jitter due to crosserase and crosstalk was calculated and compared using 1,000 random marks having 3T to 11T period. The results showed that the jitter due to crosserase turned out to be smaller than the jitter due to crosstalk.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.38-45
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• 2010

A new readout circuit involving a pixel-level reset control was studied for 2-D long wavelength infrared focal plane arrays. The integration time of each pixel can be optimized individually and automatically. Hence, the readout circuit has a wide dynamic range and good signal-to-noise ratio characteristics. The readout circuit was fabricated with a $0.35{\mu}m$ 2-poly 4-metal CMOS process for a $128{\times}128$ long wavelength infrared HgCdTe array with a pixel size of $50{\mu}m{\times}50{\mu}m$. The smart reset control with two-step background suppression improves the signal-to-noise ratio to 87dB and the dynamic range to 95.8dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.322-329
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• 2007

A single pixel photon counting type image sensor which is applicable for medical diagnosis with digitally obtained image and industrial purpose has been designed with $0.18{\mu}m$ triple-well CMOS process. The designed single pixel for readout chip is able to be operated by single supply voltage to simplify digital X-ray image sensor module and a preamplifier which is consist of folded cascode CMOS operational amplifier has been designed to enlarge signal voltage(${\Delta}Vs$), the output voltage of preamplifier. And an externally tunable threshold voltage generator circuit which generates threshold voltage in the readout chip has been newly proposed against the conventional external threshold voltage supply. In addition, A dark current compensation circuit for reducing dark current noise from photo diode is proposed and 15bit LFSR(Linear Feedback Shift Resister) Counter which is able to have high counting frequency and small layout area is designed.