scholarly journals OTRA Based Voltage Mode Third Order Quadrature Oscillator

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rajeshwari Pandey ◽  
Neeta Pandey ◽  
Gurumurthy Komanapalli ◽  
Rashika Anurag

Two topologies of operational transresistance (OTRA) based third order quadrature oscillators (QO) are proposed in this paper. The proposed oscillators are designed using a combination of lossy and lossless integrators. The proposed topologies can be made fully integrated by implementing the resistors using matched transistors operating in linear region, which also facilitates electronic tuning of oscillation frequency. The nonideality analysis of the circuit is also given and for high frequency applications self-compensation can be used. Workability of the proposed QOs is verified through PSPICE simulations using 0.5 μm AGILENT CMOS process parameters. The total harmonic distortion (THD) for both the QO designs is found to be less than 1%.

Author(s):  
Gurumurthy Komanaplli ◽  
Neeta Pandey ◽  
Rajeshwari Pandey

In this paper a new, operational transresistance amplifier (OTRA) based, third order quadrature oscillator (QO) is presented. The proposed structure forms a closed loop using a high pass filter and differentiator. All the resistors employed in the circuit can be implemented using matched transistors operating in linear region thereby making the proposed structure fully integrated and electronically tunable. The effect of non-idealities of OTRA has been analyzed which suggests that for high frequency applications self-compensation can be used. Workability of the proposed QO is verified through SPICE simulations using 0.18μm AGILENT CMOS process parameters. Total harmonic distortion (THD) for the proposed QO is found to be less than 2.5%.The sensitivity, phasenoise analysis is also discussed for the proposed structure.


Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2726
Author(s):  
Xiangwei Zhang ◽  
Quan Li ◽  
Chengying Chen ◽  
Yan Li ◽  
Fuqiang Zuo ◽  
...  

This paper presents a fully integrated 64-channel neural recording system for local field potential and action potential. It mainly includes 64 low-noise amplifiers, 64 programmable amplifiers and filters, 9 switched-capacitor (SC) amplifiers, and a 10-bit successive approximation register analogue-to-digital converter (SAR ADC). Two innovations have been proposed. First, a two-stage amplifier with high-gain, rail-to-rail input and output, and dynamic current enhancement improves the speed of SC amplifiers. The second is a clock logic that can be used to align the switching clock of 64 channels with the sampling clock of ADC. Implemented in an SMIC 0.18 μm Complementary Metal Oxide Semiconductor (CMOS) process, the 64-channel system chip has a die area of 4 × 4 mm2 and is packaged in a QFN−88 of 10 × 10 mm2. Supplied by 1.8 V, the total power is about 8.28 mW. For each channel, rail-to-rail electrode DC offset can be rejected, the referred-to-input noise within 1 Hz–10 kHz is about 5.5 μVrms, the common-mode rejection ratio at 50 Hz is about 69 dB, and the output total harmonic distortion is 0.53%. Measurement results also show that multiple neural signals are able to be simultaneously recorded.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8476
Author(s):  
Yuxuan Tang ◽  
Yulang Feng ◽  
He Hu ◽  
Cheng Fang ◽  
Hao Deng ◽  
...  

This paper presents a wideband low-noise amplifier (LNA) front-end with noise and distortion cancellation for high-frequency ultrasound transducers. The LNA employs a resistive shunt-feedback structure with a feedforward noise-canceling technique to accomplish both wideband impedance matching and low noise performance. A complementary CMOS topology was also developed to cancel out the second-order harmonic distortion and enhance the amplifier linearity. A high-frequency ultrasound (HFUS) and photoacoustic (PA) imaging front-end, including the proposed LNA and a variable gain amplifier (VGA), was designed and fabricated in a 180 nm CMOS process. At 80 MHz, the front-end achieves an input-referred noise density of 1.36 nV/sqrt (Hz), an input return loss (S11) of better than −16 dB, a voltage gain of 37 dB, and a total harmonic distortion (THD) of −55 dBc while dissipating a power of 37 mW, leading to a noise efficiency factor (NEF) of 2.66.


Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2311
Author(s):  
Ximing Fu ◽  
Kamal El-Sankary ◽  
Yadong Yin

This paper presents a driver amplifier with high bandwidth-power efficiency, high capacitor-driving capacity, and low total harmonic distortion (THD). One complementary differential pair composed of self-cascode transistors is incorporated to obtain a full input voltage swing. Flipped voltage follower (FVF) buffers are applied as second stage to drive the last class-AB output stage. Moreover, a dual-loop active-feedback frequency compensation (DLAFC) is presented, which can stabilize the proposed multistage amplifier and keep the dominant pole on high frequency to obtain high-frequency total harmonic distortion (THD) suppression. To achieve a low-frequency phase margin protection (PMP), one left half-plane (LHP) zero is introduced to compensate for the nondominant pole caused by the load capacitor. Meanwhile, two high-frequency LHP zeros are injected to achieve high-frequency phase margin boosting (PMB) and reduce the amplifier’s settling time and integration area. This proposed amplifier is implemented in a standard DBH 0.18 μm 5 V CMOS process, and it achieves over 115-dB DC gain, 150–300 MHz GBW under 0–100 p load capacitors, ultra-high THD2,3 suppression ranges from 100 kHz to 10 MHz under 1–2 V output swing, and over 250 V/μs average slew rate, by only dissipating 12.5 mW at 5 V power supply.


2011 ◽  
Vol 20 (02) ◽  
pp. 233-242 ◽  
Author(s):  
ANCA MANOLESCU ◽  
COSMIN POPA

A new linearization technique for a CMOS high frequency mixer will be presented. The reduction of the total harmonic distortion coefficient is achieved by replacing the simple differential amplifier from the basic multiplier circuit with a cross-connection differential amplifier, with the advantage of canceling the third-order harmonic from the output signal expression. The circuit was implemented in 0.35 μm CMOS technology and it was supplied at a total voltage of 6 V. The transient and Fourier analysis for high frequency input signals (ω1 = ω2 = 2.5 GHz and ω1 = 2.5 GHz; ω2 = 2.25 GHz) confirm the theoretical estimated results (an improvement in linearity of about 8 dB).


2013 ◽  
Vol 22 (09) ◽  
pp. 1340002
Author(s):  
NIKORN HEN-NGAM ◽  
JIRAYUTH MAHATTANAKUL

This paper aims at presenting an equation describing a relation between power consumption and phase noise of the widely used CMOS cross-coupled LC differential oscillator. This equation is derived by using periodic time-varying method and it relates oscillator's key performance parameters, e.g., oscillation frequency and amplitude, sideband spectrum and bias current, and CMOS process parameters. The validity of the proposed equation was confirmed by the periodic noise simulation available in the Cadence's Virtuoso Spectre Circuit Simulator.


Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Woorham Bae ◽  
Sung-Yong Cho ◽  
Deog-Kyoon Jeong

This paper presents a fully integrated Peripheral Component Interconnect (PCI) Express (PCIe) Gen4 physical layer (PHY) transmitter. The prototype chip is fabricated in a 28 nm low-power CMOS process, and the active area of the proposed transmitter is 0.23 mm2. To enable voltage scaling across wide operating rates from 2.5 Gb/s to 16 Gb/s, two on-chip supply regulators are included in the transmitter. At the same time, the regulators maintain the output impedance of the transmitter to meet the return loss specification of the PCIe, by including replica segments of the output driver and reference resistance in the regulator loop. A three-tap finite-impulse-response (FIR) equalization is implemented and, therefore, the transmitter provides more than 9.5 dB equalization which is required in the PCIe specification. At 16 Gb/s, the prototype chip achieves energy efficiency of 1.93 pJ/bit including all the interface, bias, and built-in self-test circuits.


Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1873
Author(s):  
Chen Cai ◽  
Xuqiang Zheng ◽  
Yong Chen ◽  
Danyu Wu ◽  
Jian Luan ◽  
...  

This paper presents a fully integrated physical layer (PHY) transmitter (TX) suiting for multiple industrial protocols and compatible with different protocol versions. Targeting a wide operating range, the LC-based phase-locked loop (PLL) with a dual voltage-controlled oscillator (VCO) was integrated to provide the low jitter clock. Each lane with a configurable serialization scheme was adapted to adjust the data rate flexibly. To achieve high-speed data transmission, several bandwidth-extended techniques were introduced, and an optimized output driver with a 3-tap feed-forward equalizer (FFE) was proposed to accomplish high-quality data transmission and equalization. The TX prototype was fabricated in a 28-nm CMOS process, and a single-lane TX only occupied an active area of 0.048 mm2. The shared PLL and clock distribution circuits occupied an area of 0.54 mm2. The proposed PLL can support a tuning range that covers 6.2 to 16 GHz. Each lane's data rate ranged from 1.55 to 32 Gb/s, and the energy efficiency is 1.89 pJ/bit/lane at a 32-Gb/s data rate and can tune an equalization up to 10 dB.


1995 ◽  
Vol 31 (11) ◽  
pp. 1974-1980 ◽  
Author(s):  
Liming Zhang ◽  
D.A. Ackerman

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 734
Author(s):  
Karolis Kiela ◽  
Marijan Jurgo ◽  
Vytautas Macaitis ◽  
Romualdas Navickas

This article presents a wideband reconfigurable integrated low-pass filter (LPF) for 5G NR compatible software-defined radio (SDR) solutions. The filter uses Active-RC topology to achieve high linearity performance. Its bandwidth can be tuned from 2.5 MHz to 200 MHz, which corresponds to a tuning ratio of 92.8. The order of the filter can be changed between the 2nd, 4th, or 6th order; it has built-in process, voltage, and temperature (PVT) compensation with a tuning range of ±42%; and power management features for optimization of the filter performance across its entire range of bandwidth tuning. Across its entire order, bandwidth, and power configuration range, the filter achieves in-band input-referred third-order intercept point (IIP3) between 32.7 dBm and 45.8 dBm, spurious free dynamic range (SFDR) between 63.6 dB and 79.5 dB, 1 dB compression point (P1dB) between 9.9 dBm and 14.1 dBm, total harmonic distortion (THD) between −85.6 dB and −64.5 dB, noise figure (NF) between 25.9 dB and 31.8 dB and power dissipation between 1.19 mW and 73.4 mW. The LPF was designed and verified using 65 nm CMOS process; it occupies a 0.429 mm2 area of silicon and uses a 1.2 V supply.


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