Application of cascode level shifter for EMI reduction in LCD driver IC

2015 ◽  
Vol 32 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Soo-Woo Kim ◽  
Ho-Yong Choi ◽  
Sehyuk An ◽  
Nam-Soo Kim

Purpose – This paper aims to design the circuit for electromagnetic interface (EMI) reduction in liquid crystal display (LCD). Design/methodology/approach – The cascode level shifter and segmented driver circuit are applied in LCD column driver integrated circuit (IC) for EMI reduction. Cascode current mirror is used in the proposed level shifter for DC voltage biasing and reduction of the driving current which passes through the level shifter. The on-off switching currents and transient times are measured and compared between the conventional and proposed level shifters. Additionally, a segmented data latch is obtained by the timing spread solution in data latch, and applied to split the large peak switching current into a number of smaller peak current. The timing spread-operation does not actually reduce the total power of the noise, instead, it spreads the noise power evenly over the frequency bandwidth. The optimal number of latch is dependent on the operating frequency and EMI allowance. The column driver IC and clock controller are integrated in 0.18 μm CMOS technology with 1-poly and 4-metal process. Findings – The post-layout simulation shows that the proposed column driver circuit for LCD driver IC significantly reduces the peak switching current, and it results in the reduction of EMI noise level by more than 15 dB. It is obtained with 20 segmented operations in data latch at 40 MHz frequency. Originality/value – The advantage of the cascode current source is that it can provide a well-controlled bias current with an accurate current transfer ratio. To reduce the EMI noise in LCD driver circuit, the cascode current source is properly located for the DC bias block in the level shifter. The application is rarely done by others, and a significant EMI noise reduction is found. The well-controlled current source provides a high performance switching in the level shifter.

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 464 ◽  
Author(s):  
Wang ◽  
Guo ◽  
Zhou ◽  
Wu ◽  
Luan ◽  
...  

A 3GS/s 12-bit current-steering digital-to-analog converter (DAC) fabricated in 55 nm complementary metal–oxide–semiconductor (CMOS) technology has been presented. A partial randomization dynamic element matching (PRDEM) method based on switching sequence optimization is proposed to mitigate the mismatch effect and suppress the harmonic distortion with low hardware complexity. In the switching current cell, the cascode structure together with “always-ON” small current sources are used to keep the output impedance high and uniform. A compact layout of the switching current array is carefully designed, featuring short wires routing and small parasitic capacitance. According to the measured results at 3GS/s, this DAC demonstrates a spurious-free dynamic range (SFDR) of 74.64 dBc at low frequency and 50 dBc at 1.5 GHz output. The chip occupies an active area of 0.2 × 0.48 mm2 and consumes a total power of 495 mW.


2021 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Orazio Aiello

The paper deals with the immunity to Electromagnetic Interference (EMI) of the current source for Ultra-Low-Voltage Integrated Circuits (ICs). Based on the properties of IC building blocks, such as the current-splitter and current correlator, a novel current generator is conceived. The proposed solution is suitable to provide currents to ICs operating in the sub-threshold region even in the presence of an electromagnetic polluted environment. The immunity to EMI of the proposed solution is compared with that of a conventional current mirror and evaluated by analytic means and with reference to the 180 nm CMOS technology process. The analysis highlights how the proposed solution generates currents down to nano-ampere intrinsically robust to the Radio Frequency (RF) interference affecting the input of the current generator, differently to what happens to the output current of a conventional mirror under the same conditions.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Neeta Pandey ◽  
Bharat Choudhary ◽  
Kirti Gupta ◽  
Ankit Mittal

This paper proposes new positive feedback source coupled logic (PFSCL) tristate buffers suited to bus applications. The proposed buffers use switch to attain high impedance state and modify the load or the current source section. An interesting consequence of this is overall reduction in the power consumption. The proposed tristate buffers consume half the power compared to the available switch based counterpart. The issues with available PFSCL tristate buffers based bus implementation are identified and benefits of employing the proposed tristate buffer topologies are put forward. SPICE simulation results using TSMC 180 nm CMOS technology parameters are included to support the theoretical formulations. The performance of proposed tristate buffer topologies is examined on the basis of propagation delay, output enable time, and power consumption. It is found that one of the proposed tristate buffer topology outperforms the others in terms of all the performance parameters. An examination of behavior of available and the proposed PFSCL tristate buffer topologies under parameter variations and mismatch shows a maximum variation of 14%.


2021 ◽  
Vol 9 ◽  
Author(s):  
N. Demaria

The High Luminosity Large Hadron Collider (HL-LHC) at CERN will constitute a new frontier for the particle physics after the year 2027. Experiments will undertake a major upgrade in order to stand this challenge: the use of innovative sensors and electronics will have a main role in this. This paper describes the recent developments in 65 nm CMOS technology for readout ASIC chips in future High Energy Physics (HEP) experiments. These allow unprecedented performance in terms of speed, noise, power consumption and granularity of the tracking detectors.


Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Majeed ◽  
Esam Alkaldy

Purpose This study aims to replace current multi-layer and coplanar wire crossing methods in QCA technology to avoid fabrication difficulties caused by them. Design/methodology/approach Quantum-dot cellular automata (QCA) is one of the newly emerging nanoelectronics technology tools that is proposed as a good replacement for complementary metal oxide semiconductor (CMOS) technology. This technology has many challenges, among them being component interconnection and signal routing. This paper will propose a new wire crossing method to enhance layout use in a single layer. The presented method depends on the central cell clock phase to enable two signals to cross over without interference. QCADesigner software is used to simulate a full adder circuit designed with the proposed wire crossing method to be used as a benchmark for further analysis of the presented wire crossing approach. QCAPro software is used for power dissipation analysis of the proposed adder. Findings A new cost function is presented in this paper to draw attention to the fabrication difficulties of the technology when designing QCA circuits. This function is applied to the selected benchmark circuit, and the results show good performance of the proposed method compared to others. The improvement is around 59, 33 and 75% compared to the best reported multi-layer wire crossing, coplanar wire crossing and logical crossing, respectively. The power dissipation analysis shows that the proposed method does not cause any extra power consumption in the circuit. Originality/value In this paper, a new approach is developed to bypass the wire crossing problem in the QCA technique.


2016 ◽  
Vol 62 (2) ◽  
pp. 187-196
Author(s):  
Karim El khadiri ◽  
Hassan Qjidaa

Abstract A class-D audio amplifier with analog volume control (AVC) for portable applications is proposed in this paper. The proposed class-D consist of two sections. First section is an analog volume control which consists of an integrator, an analog MUX and a programmable gain amplifier (PGA). The AVC is implemented with three analog inputs (Audio, Voice, FM). Second section is a driver which consists of a ramp generator, a comparator, a level shifter and a gate driver. The driver is designed to obtain a low distortion and a high efficiency. Designed with 0.18 um 1P6M CMOS technology, the class-D audio amplifier with AVC achieves a total root-mean-square (RMS) output power of 0.5W, a total harmonic distortion plus noise (THD+N) at the 8-Ω load less than 0.06% and a power efficiency of 90% with a total area of 1.74 mm2.


Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 183-192
Author(s):  
Muhammad Yasir Faheem ◽  
Shun'an Zhong ◽  
Xinghua Wang ◽  
Muhammad Basit Azeem

Purpose Successive approximation register (SAR) analogue to digital converter (ADC) is well-known with regard to low-power operations. To make it energy-efficient and time-efficient, scientists are working for the last two decades, and it still needs the attention of the researchers. In actual work, there is no mechanism and circuitry for the production of two simultaneous comparator outputs in SAR ADC. Design/methodology/approach A small-sized, low-power and energy-efficient circuitry of a dual comparator and an amplifier is presented, which is the most important part of SAR ADC. The main idea is to design a multi-dimensional circuit which can deliver two quick parallel comparisons. The circuitry of the three devices is combined and miniaturized by introducing a lower number of MOSFET’s and small-sized capacitors in such a way that there is no need for any matching and calibration. Findings The supply voltage of the proposed comparator is 0.7 V with the overall power consumption of 0.257mW. The input and clock frequencies are 5 and 50 MHz, respectively. There is no requirement for any offset calibration and mismatching concerns due to sharing and centralization of spider-latch circuitry. The total offset voltages are 0.13 0.31 mV with 0.3VDD to VDD. All the components are small-sized and miniaturized to make the circuit cost-effective and energy-efficient. The rise and response time of comparator is around 100 ns. SNDR improved from 56 to 65 dB where the input-referred noise of an amplifier is 98mVrms. Originality/value The proposed design has no linear-complexity compared with the conventional comparator in both modes (working and standby); it is ultimately intended and designed for 11-bit SAR ADC. The circuit based on three rapid clock pulses for three different modes includes amplification and two parallel comparisons controlled and switched by a latch named as “spider-latch”.


Circuit World ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 300-310
Author(s):  
Piyush Tankwal ◽  
Vikas Nehra ◽  
Sanjay Prajapati ◽  
Brajesh Kumar Kaushik

Purpose The purpose of this paper is to analyze and compare the characteristics of hybrid conventional complementary metal oxide semiconductor/magnetic tunnel junction (CMOS/MTJ) logic gates based on spin transfer torque (STT) and differential spin Hall effect (DSHE) magnetic random access memory (MRAM). Design/methodology/approach Spintronics technology can be used as an alternative to CMOS technology as it is having comparatively low power dissipation, non-volatility, high density and high endurance. MTJ is the basic spin based device that stores data in form of electron spin instead of charge. Two mechanisms, namely, STT and SHE, are used to switch the magnetization of MTJ. Findings It is observed that the power consumption in DSHE based logic gates is 95.6% less than the STT based gates. DSHE-based write circuit consumes only 5.28 fJ energy per bit. Originality/value This paper describes how the DSHE-MRAM is more effective for implementing logic circuits in comparison to STT-MRAM.


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