A CMOS Automatic Gain Control Circuit for Biomedical Applications

2015 ◽  
Vol 645-646 ◽  
pp. 1308-1313
Author(s):  
Zhi Qiang Gao ◽  
Fu Xiang Huang ◽  
Jing Li ◽  
Liang Yin ◽  
Xiao Wei Liu

In this paper, a low-voltage automatic gain control (AGC) circuits is presented. The proposed circuit uses a novel approximated exponential function to increase the dB-linear output range. The three-stage AGC is fabricated in 0.18μm CMOS technology and shows the maximum gain variation of more than 100dB and a 67dB linear range with linearity error of less than ±1dB. The range of gain variation can be controlled from 34 to 101dB. The AGC dissipates less than 2.3mA under 1.8V supply voltage while occupying 0.4mm2 of chip area.

Author(s):  
Rarika Ravi ◽  
Anu Assis

<p>This paper discusses about different receiver designs adopted so far for various electronic toll collection systems. A comparative analysis based on the discussions is also provided. It shows that each design has it's own advantages and disadvantages compared to others. The main aim of this paper is to identify the most suitable design. The researches shows that the receiver design described in the 5.8GHz digitally controlled DSRC receiver for Chinese electronic toll collection system is the most suitable one. Here all RF, IF blocks and digital baseband for on-chip automatic gain control, are integrated on an RF-SoC. The proposed digitally controlled LNA and mixer circuits are elaborated. The technology used is 0.13μm CMOS technology. The RF block occupies a chip area of 0.75mm2. It consumes 22mA under a 1.5V supply voltage. The bit error rate maintains better than 10-6, the input power level varies from -75dBm to -8dBm. This design provides a receiver sensitivity improvement of at least 25%, and a dynamic range enhancement of at least 12%.</p>


Author(s):  
Jetsdaporn Satansup ◽  
Worapong Tangsrirat

A circuit technique for designing a compact low-voltage current-mode multiplier/divider circuit in CMOS technology is presented.  It is based on the use of a compact current quadratic cell able to operate at low supply voltage.  The proposed circuit is designed and simulated for implementing in TSMC 0.25-m CMOS technology with a single supply voltage of 1.5 V.  Simulation results using PSPICE, accurately agreement with theoretical ones, have been provided, and also demonstrate a maximum linearity error of 1.5%, a THD less than 2% at 100 MHz, a total power consumption of 508 W, and -3dB small-signal frequency of about 245 MHz.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gim Heng Tan ◽  
Roslina Mohd Sidek ◽  
Harikrishnan Ramiah ◽  
Wei Keat Chong ◽  
De Xing Lioe

This journal presents an ultra-low-voltage current bleeding mixer with high LO-RF port-to-port isolation, implemented on 0.13 μm standard CMOS technology for ZigBee application. The architecture compliments a modified current bleeding topology, consisting of NMOS-based current bleeding transistor, PMOS-based switching stage, and integrated inductors achieving low-voltage operation and high LO-RF isolation. The mixer exhibits a conversion gain of 7.5 dB at the radio frequency (RF) of 2.4 GHz, an input third-order intercept point (IIP3) of 1 dBm, and a LO-RF isolation measured to 60 dB. The DC power consumption is 572 µW at supply voltage of 0.45 V, while consuming a chip area of 0.97 × 0.88 mm2.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1004
Author(s):  
Massimo Vatalaro ◽  
Marco Lanuzza ◽  
Felice Crupi ◽  
Tatiana Moposita ◽  
Lionel Trojman ◽  
...  

This paper presents a novel low-power low-voltage analog implementation of the softmax function, with electrically adjustable amplitude and slope parameters. We propose a modular design, which can be scaled by the number of inputs (and of corresponding outputs). It is composed of input current–voltage linear converter stages (1st stages), MOSFETs operating in a subthreshold regime implementing the exponential functions (2nd stages), and analog divider stages (3rd stages). Each stage is only composed of p-type MOSFET transistors. Designed in a 0.18 µm CMOS technology (TSMC), the proposed softmax circuit can be operated at a supply voltage of 500 mV. A ten-input/ten-output realization occupies a chip area of 2570 µm2 and consumes only 3 µW of power, representing a very compact and energy-efficient option compared to the corresponding digital implementations.


2008 ◽  
Vol 6 ◽  
pp. 213-217 ◽  
Author(s):  
H. Uhrmann ◽  
W. Gaberl ◽  
H. Zimmermann

Abstract. In this paper we examine the impact of deep sub-micron CMOS technology on analog circuit design with a special focus on the noise performance and the ability to design low-noise preamplifiers. To point out, why CMOS technology can grow to a key technology in low-noise and high-speed applications, various amplifier stages, applied in literature, are compared. One, that fits as a current preamplifier for low-noise applications, is the current mirror. Starting from the basic current mirror, an enhanced current preamplifier is developed, that offers low-noise and high-speed operation. The suggested chip is realized in 0.12 μm CMOS technology and needs a chip area of 100 μm×280 μm. It consumes about 15 mW at a supply voltage of 1.5 V. The presented current preamplifier has a bandwidth of 750 MHz and a gain of 36 dB. The fields of application for current preamplifiers are, for instance, charge amplifiers, amplifiers for low-voltage differential signaling (LVDS) based point-to-point data links or preamplifiers for photodetectors.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate.


Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2931
Author(s):  
Waldemar Jendernalik ◽  
Jacek Jakusz ◽  
Grzegorz Blakiewicz

Buffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more general method for buffer-based filter synthesis is developed and presented. The method uses RLC ladder prototypes to obtain filters of arbitrary orders. In addition, a set of novel circuit solutions with ultra-low voltage and power are proposed. The introduced circuits were synthesized and simulated using 180-nm CMOS technology of X-FAB. One of the designed circuits is a fourth-order, low-pass filter that features: 100-Hz passband, 0.4-V supply voltage, power consumption of less than 5 nW, and dynamic range above 60 dB. Moreover, the total capacitance of the proposed filter (31 pF) is 25% lower compared to the structure synthesized using a conventional cascade method (40 pF).


Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 69 ◽  
Author(s):  
Taufiq Alif Kurniawan ◽  
Toshihiko Yoshimasu

This paper presents a 2.5-GHz low-voltage, high-efficiency CMOS power amplifier (PA) IC in 0.18-µm CMOS technology. The combination of a dual-switching transistor (DST) and a third harmonic tuning technique is proposed. The DST effectively improves the gain at the saturation power region when the additional gain extension of the secondary switching transistor compensates for the gain compression of the primary one. To achieve high-efficiency performance, the third harmonic tuning circuit is connected in parallel to the output load. Therefore, the flattened drain current and voltage waveforms are generated, which in turn reduce the overlapping and the dc power consumption significantly. In addition, a 0.5-V back-gate voltage is applied to the primary switching transistor to realize the low-voltage operation. At 1 V of supply voltage, the proposed PA has achieved a power added efficiency (PAE) of 34.5% and a saturated output power of 10.1 dBm.


2019 ◽  
Vol 82 (1) ◽  
Author(s):  
Florence Choong ◽  
Mamun Ibne Reaz ◽  
Mohamad Ibrahim Kamaruzzaman ◽  
Md. Torikul Islam Badal ◽  
Araf Farayez ◽  
...  

Digital controlled oscillator (DCO) is becoming an attractive replacement over the voltage control oscillator (VCO) with the advances of digital intensive research on all-digital phase locked-loop (ADPLL) in complementary metal-oxide semiconductor (CMOS) process technology. This paper presents a review of various CMOS DCO schemes implemented in ADPLL and relationship between the DCO parameters with ADPLL performance. The DCO architecture evaluated through its power consumption, speed, chip area, frequency range, supply voltage, portability and resolution. It can be concluded that even though there are various schemes of DCO that have been implemented for ADPLL, the selection of the DCO is frequently based on the ADPLL applications and the complexity of the scheme. The demand for the low power dissipation and high resolution DCO in CMOS technology shall remain a challenging and active area of research for years to come. Thus, this review shall work as a guideline for the researchers who wish to work on all digital PLL.


Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1547
Author(s):  
Xiangyu Chen ◽  
Yasuhiro Takahashi

In this paper, a transimpedance amplifier (TIA) based on floating active inductors (FAI) is presented. Compared with conventional TIAs, the proposed TIA has the advantages of a wider bandwidth, lower power dissipation, and smaller chip area. The schematics and characteristics of the FAI circuit are explained. Moreover, the proposed TIA employs the combination of capacitive degeneration, the broadband matching network, and the regulated cascode input stage to enhance the bandwidth and gain. This turns the TIA design into a fifth-order low pass filter with Butterworth response. The TIA is implemented using 0.18 μ m Rohm CMOS technology and consumes only 10.7 mW with a supply voltage of 1.8 V. When used with a 150 fF photodiode capacitance, it exhibits the following characteristics: gain of 41 dB Ω and −3 dB frequency of 10 GHz. This TIA occupies an area of 180 μ m × 118 μ m.


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