• ETRI Journal
• /
• 제30권5호
• /
• pp.644-652
• /
• 2008

In this paper, a low-power CMOS interface circuit is designed and demonstrated for capacitive sensor applications, which is implemented using a standard 0.35-${\mu}m$ CMOS logic technology. To achieve low-power performance, the low-voltage capacitance-to-pulse-width converter based on a self-reset operation at a supply voltage of 1.5 V is designed and incorporated into a new interface circuit. Moreover, the external pulse signal for the reset operation is made unnecessary by the employment of the self-reset operation. At a low supply voltage of 1.5 V, the new circuit requires a total power consumption of 0.47 mW with ultra-low power dissipation of 157 ${\mu}W$ of the interface-circuit core. These results demonstrate that the new interface circuit with self-reset operation successfully reduces power consumption. In addition, a prototype wireless sensor-module with the proposed circuit is successfully implemented for practical applications. Consequently, the new CMOS interface circuit can be used for the sensor applications in ubiquitous sensor networks, where low-power performance is essential.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
• /
• pp.419-421
• /
• 1996

We propose the digitized pressure sensor and the interface circuit to read directly the pressure signal in the digital form. The interface circuit has the control clock, comparator, and bit value decision circuit. The digitized sensor and interface circuit are integrated on the one chip using the post processing after IC fabrication. The dimension of the fabricated digitized pressure sensor is $3{\times}6{\times}1mm^3$.

• 한국정보통신학회논문지
• /
• 제25권8호
• /
• pp.1130-1133
• /
• 2021

In this paper, a miniaturized sensor interface circuit for the respiration detection system is proposed. Respiratory diagnosis is one of the main ways to predict various diseases. The proposed system consists of respiration detection sensor, temperature sensor, and interface circuits. Electrochemical type gas sensor using solid electrolytes is adopted for respiration detection. Proposed system performs sensing, amplification, analog-to-digital conversion, digital signal processing, and i2c communication. And also proposed system has a small form factor and low-cost characteristics through optimization and miniaturization of the circuit structure. Moreover, technique for sensor degradation compensation is introduced to obtain high accuracy. The size of proposed system is about 1.36 cm².

• ETRI Journal
• /
• 제29권1호
• /
• pp.70-78
• /
• 2007

A new low-voltage CMOS interface circuit with digital output for piezo-resistive transducer is proposed. An input current sensing configuration is used to detect change in piezo-resistance due to applied pressure and to allow low-voltage circuit operation. A simple 1-bit first-order delta-sigma modulator is used to produce an output digital bitstream. The proposed interface circuit is realized in a 0.35 ${\mu}m$ CMOS technology and draws less than 200 ${\mu}A$ from a single 1.5 V power supply voltage. Simulation results show that the circuit can achieve an equivalent output resolution of 9.67 bits with less than 0.23% non-linearity error.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2007년도 하계학술대회 논문집
• /
• pp.247-249
• /
• 2007

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60㎐ power-line noise, amplifier, and a level circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권6호
• /
• pp.793-799
• /
• 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.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.138-142
• /
• 2004

In this paper, we present a new method for monitoring of ECU's sensor signals of vehicle. In order to measure the ECU's sensor signals, the interfaced circuit is designed to communicate ECU and the Embedded Linux is used to monitor communication result through Web the Embedded Linux system and this system is said "ECU Interface Part". In ECU Interface Part the interface circuit is designed to match voltage level between ECU and SA-1110 micro controller and interface circuit to communicate ECU according to the ISO, SAE communication protocol standard. Because Embedded Linux does not allow to access hardware directly in application level, anyone who wants to modify any low level hardware must develop device driver. To monitor ECU's sensor signals the most important thing is to match serial level between ECU and ECU Interface Part. It means to communicate correctly between two hardware we need to match voltage and signal level, and need to match baudrate. The voltage of SA-1110 is 0 ${\sim}$ +3.3V and ECU is 0 ${\sim}$ +12V and, ECU's communication Line K does multiple operation so, the interface circuit is used to match voltage and signal level. In Addition to ECU's baudrate is 10400bps, it's not standard baudrate in computer environment. So, we need to develop a device driver to control the interface circuit, and change baudrate. To monitor ECU's sensor signals through web there's a network socket program is working in Embedded Linux. It works as server program and manages user's connections and commands. Anyone who wants to monitor ECU's sensor signals he just only connect to Embedded Linux system with web browser then, Embedded Linux webserver will return the ActiveX webbased measurement software. It works in web browser and inits ECU, as a result it returns sensor signals through web. All the programs are developed with GCC(GNU C Compiler) and, webbased measurement software is developed with Borland C++ Builder.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제55권12호
• /
• pp.550-557
• /
• 2006

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper is proposed two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value(MAV) circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• E2M - 전기 전자와 첨단 소재
• /
• 제8권3호
• /
• pp.254-260
• /
• 1995

A method is described for the design and fabrication of the sensor interface circuits on the Clark electrodes for the dissolved oxygen(DO). The discussion includes a method for the +5 V single-supply driving for the sensor circuits, which has low power comsumption for the front-end electronics. DO probe under test is composed of the Clark electrode with silver anode, gold cathode and the electrolyte of half saturated KCI solution and the FEP teflon memtrance for the oxygen penetration. Typical polarograms for the DO probes by using this sensor circuit reveals high accuracy over 99% of the I to V conversion. Partial pressure of oxygen obtained from the polarograms are well suited to the results calculated. It is expected that the proposed sensor circuits can be utilized into the customized IC for the battery-driven small-size DO meters.

• 한국전자통신학회논문지
• /
• 제14권3호
• /
• pp.529-536
• /
• 2019

스마트 센서 시스템에 압전 에너지 하베스터를 적용하기 위해서는 AC-DC 정류기를 비롯한 에너지 하베스트 인터페이스 회로가 필수적이다. 본 논문에서는 기본적인 회로인 Full Bridge Rectifier(: FBR) 회로와 동기식 압전 에너지 하베스트 인터페이스 회로의 성능을 보드레벨 시뮬레이션으로 비교하였다. 그 결과, 동기식 압전 에너지 하베스트 인터페이스 회로 중 하나인 Synchronous Electric Charge Extraction(: SECE) 회로가 FBR에 비해 출력 전력이 약 4 배 이상 더 컸고, 부하 변동에도 변화가 거의 없었다. 그리고, 출력 전압이 40V 이상인 압전 에너지 하베스터용 SECE 회로에 필수적인 고전압 비교기를 0.35 um BCD 공정으로 설계하였다. 설계한 고전압 비교기를 적용한 SECE 회로는 출력 전력이 FBR 회로 보다 427 % 향상됨을 검증하였다.