scholarly journals A low-voltage CMOS current-mode differential front-end for optical communications

2021 ◽  
Author(s):  
Bendong Sun
Keyword(s):  
Optical Communications ◽  
Dynamic Range ◽  
Low Voltage ◽  
Supply Voltage ◽  
Current Mode ◽  
Building Blocks ◽  
Switching Noise ◽  
Current Feedback ◽  
Fully Differential ◽  
Digital Circuitry

This thesis deals with the design of a low-voltage fully-differential CMOS current-mode preamplifier for optical communications. An in-depth comparative analysis of the building blocks of low-voltage CMOS current-mode circuits is carried out. Two new bandwidth enhancement techniques, namely inductor series-peaking and current feedback, are introduced and implemented in the design. The feedback also reduces the value of the series-peaking inductor. The minimum supply voltage of the amplifier is only one threshold voltage plus one pinch-off voltage. The preamplifier has a balanced differential topology such that the effect of bias dependent mismatches is minimized and the amplifier is insensitive to the switching noise caused by the digital circuitry. Negative differential current feedbacks are implemented to boost the bandwidth and increase the dynamic range.

scholarly journals A low-voltage CMOS current-mode differential front-end for optical communications

2021 ◽  
Author(s):  
Bendong Sun
Keyword(s):  
Optical Communications ◽  
Dynamic Range ◽  
Low Voltage ◽  
Supply Voltage ◽  
Current Mode ◽  
Building Blocks ◽  
Switching Noise ◽  
Current Feedback ◽  
Fully Differential ◽  
Digital Circuitry

This thesis deals with the design of a low-voltage fully-differential CMOS current-mode preamplifier for optical communications. An in-depth comparative analysis of the building blocks of low-voltage CMOS current-mode circuits is carried out. Two new bandwidth enhancement techniques, namely inductor series-peaking and current feedback, are introduced and implemented in the design. The feedback also reduces the value of the series-peaking inductor. The minimum supply voltage of the amplifier is only one threshold voltage plus one pinch-off voltage. The preamplifier has a balanced differential topology such that the effect of bias dependent mismatches is minimized and the amplifier is insensitive to the switching noise caused by the digital circuitry. Negative differential current feedbacks are implemented to boost the bandwidth and increase the dynamic range.

An Ultra-Low-Voltage Low-Power Current-Mode True RMS-to-DC Converter

2016 ◽  
Vol 25 (06) ◽  
pp. 1650066 ◽  
Author(s):  
Pantre Kompitaya ◽  
Khanittha Kaewdang
Keyword(s):  
Integrated Circuits ◽  
Low Power ◽  
High Performance ◽  
Dynamic Range ◽  
Low Voltage ◽  
Supply Voltage ◽  
Circuit Complexity ◽  
Current Mode ◽  
Cmos Technology ◽  
Low Supply Voltage

A current-mode CMOS true RMS-to-DC (RMS: root-mean-square) converter with very low voltage and low power is proposed in this paper. The design techniques are based on the implicit computation and translinear principle by using CMOS transistors that operate in the weak inversion region. The circuit can operate for two-quadrant input current with wide input dynamic range (0.4–500[Formula: see text]nA) with an error of less than 1%. Furthermore, its features are very low supply voltage (0.8[Formula: see text]V), very low power consumption ([Formula: see text]0.2[Formula: see text]nW) and low circuit complexity that is suitable for integrated circuits (ICs). The proposed circuit is designed using standard 0.18[Formula: see text][Formula: see text]m CMOS technology and the HSPICE simulation results show the high performance of the circuit and confirm the validity of the proposed design technique.

scholarly journals Investigation of PVT-Aware STT-MRAM Sensing Circuits for Low-VDD Scenario

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
High Speed ◽  
Low Voltage ◽  
Supply Voltage ◽  
Random Access ◽  
Magnetic Tunnel Junction ◽  
Complementary Metal Oxide Semiconductor ◽  
Current Mode ◽  
Cmos Technology ◽  
Oxide Semiconductor

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.

scholarly journals Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2931
Author(s):  
Waldemar Jendernalik ◽  
Jacek Jakusz ◽  
Grzegorz Blakiewicz
Keyword(s):  
Dynamic Range ◽  
Low Voltage ◽  
Supply Voltage ◽  
Low Frequency ◽  
Cmos Technology ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Biomedical Sensors ◽  
Filter Synthesis ◽  
Cascade Method

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).

A High-Speed Fully Differential Telescopic Op-Amp for Active Filter Designs in V2X Applications

2021 ◽  
Author(s):  
Furkan Barin ◽  
Ertan Zencir
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Supply Voltage ◽  
Active Filter ◽  
Ultra Wideband ◽  
Two Stage ◽  
Fully Differential ◽  
Op Amp ◽  
Current Mirrors ◽  
Design Techniques

In this paper, an ultra-wideband fully differential two-stage telescopic 65-nm CMOS op-amp is presented, which uses low-voltage design techniques such as level shifter circuits and low-voltage cascode current mirrors. The designed op-amp consists of two stages. While the telescopic first stage provides high speed and low swing, the second stage provides high gain and large swing. Common-mode feedback circuits (CMFB), which contain five transistors OTA and sensing resistors, are used to set the first-stage output to a known value. The designed two-stage telescopic operational amplifier has 41.04[Formula: see text]dB lower frequency gain, 1.81[Formula: see text]GHz gain-bandwidth product (GBW) and 51.9∘ phase margin under 5[Formula: see text]pF load capacitance. The design consumes a total current of 11.9[Formula: see text]mA from a 1.2-V supply voltage. Presented fully differential two-stage telescopic op-amp by using low-voltage design techniques is suitable for active filter in vehicle-to-everything (V2X) applications with 120[Formula: see text][Formula: see text]m[Formula: see text]m layout area.

scholarly journals A low-voltage CMOS current-mode incremental signaling scheme for high-speed parallel links

2021 ◽  
Author(s):  
Tao Wang
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Low Cost ◽  
Current Mode ◽  
Cmos Technology ◽  
Fully Differential ◽  
Parallel Links ◽  
Data Links ◽  
Parallel Data ◽  
The Cost

Point-to-point parallel links are widly used in short-distance high-speed data communications. For these links, the design goal is not only to integrate a large number of I/Os in the systems, but also to increase the bit rate per I/O. The cost per I/O has to be kept low as performance improves. Voltage and timing error sources limit the performance of data links and affect its robustnest. These kinds of noise impose greater challenges in parallel data links, such as inter-signal timing skew and inter-signal cross-talk. The use of low-cost schemes, such as single-ended signaling, is effected signaficantly [sic] by the voltage and timging [sic] noise. Fully differential signaling schemes, two physical paths per signal channel, significantly increases the cost of system. Therefore, overcoming the voltage noise, keeping the cost low are two challenges in high-speed parallel links. In this thesis, we propose a new current-mode signaling scheme current-mode incremtnal [sic] signaling for high-speed parallel links. Also, the circuits of the receiver called current-integrating receiver are presented. To assess the effectiveness of the proposed signaling scheme, a 4-bit parallel link consisting of four bipolar current-mode drivers, five 10 cm microstrip lines with a FR4 substrate, and four proposed current-integrating receivers is implemented in UMC 0.13[micro]m, 1.2V CMOS technology and analyzed using SpectreRF from Cadence Design Systems with BSIM3V3 device models. Simulation results demonstrate that the proposed current-mode incremental signaling scheme and the current-integrating receiver are capable of transmitting parallel data at 2.5 Gbyte/s.

scholarly journals A New Phase-Locked Loop with Active Inductor Ring Oscillator

2021 ◽  
Author(s):  
Mohamad El-Hage
Keyword(s):  
Phase Noise ◽  
High Speed ◽  
Low Voltage ◽  
Building Blocks ◽  
Phase Locked Loop ◽  
Timing Jitter ◽  
Ring Oscillator ◽  
Control Voltage ◽  
Active Inductor ◽  
Switching Noise

Many of today's applications require that a phase-locked loop (PLL) operate at high speeds, while maintaining reasonable phase noise and jitter performance. Voltage-controlled oscillators (VCO) are important building blocks in PLLs. More importantly, the VCO is the major contributor of phase noise in a PLL. The noisy environment, mainly due to the switching noise generated by the digital portion of these systems. imposes stringent constraints on the design of VCOs, especially phase noise or timing jitter. The switching noise originated in the digital portion of the systems are coupled to the supply and ground rails of the VCO of PLLs. Another important block of a PLL is the charge-pump, a block that is responsible for generating the control voltage to be applied to the VCO. The stability or fluctuation of the control voltage, can severely affect the phase noise performance of the VCO. The research in this thesis, centered on (i) the design considerations of CMOS charge-pumps, (ii) the timing jitter of the delay-cells of low-voltage CMOS ring-VCOs and (iii) the design of a high-speed ring oscillator. A PLL was designed using a new active inductor 6.3-GHz ring oscillator, with a tuning range of +/- 15% was designed in 0.18um CMOS technology. The ring oscillator employed active inductor loads that resulted in an improvement of about 42% in oscillation frequency when compared to the conventional resistor loaded ring oscillator.

scholarly journals A New Low-Voltage Low-Power Dual-Mode VCII-Based SIMO Universal Filter

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 765 ◽  
Author(s):  
Leila Safari ◽  
Gianluca Barile ◽  
Giuseppe Ferri ◽  
Vincenzo Stornelli
Keyword(s):  
Low Power ◽  
Transfer Functions ◽  
Low Voltage ◽  
Supply Voltage ◽  
Building Blocks ◽  
Cmos Technology ◽  
Universal Filter ◽  
Dual Mode ◽  
Input Multiple Output ◽  
Low Pass

In this paper, a new low-voltage low-power dual-mode universal filter is presented. The proposed circuit is implemented using inverting current buffer (I-CB) and second-generation voltage conveyors (VCIIs) as active building blocks and five resistors and three capacitors as passive elements. The circuit is in single-input multiple-output (SIMO) structure and can produce second-order high-pass (HP), band-pass (BP), low-pass (LP), all-pass (AP), and band-stop (BS) transfer functions. The outputs are available as voltage signals at low impedance Z ports of the VCII. The HP, BP, AP, and BS outputs are also produced in the form of current signals at high impedance X ports of the VCIIs. In addition, the AP and BS outputs are also available in inverting type. The proposed circuit enjoys a dual-mode operation and, based on the application, the input signal can be either current or voltage. It is worth mentioning that the proposed filter does not require any component matching constraint and all sensitivities are low, moreover it can be easily cascadable. The simulation results using 0.18 μm CMOS technology parameters at a supply voltage of ±0.9 V are provided to support the presented theory.

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