Operational transconductance amplifier-based comparator for high frequency applications using 22 nm FinFET technology

<p><span>Fin field-effect transistor (FinFET) based analog circuits are gaining importance over metal oxide semiconductor field effect transistor (MOSFET) based circuits with stability and high frequency operations. Comparator that forms the sub block of most of the analog circuits is designed using operational transconductance amplifier (OTA). The OTA is designed using new design procedures and the comparator circuit is designed integrating the sub circuits with OTA. The building blocks of the comparator design such as input level shifter, differential pair with cascode stage and class AB amplifier for output swing are designed and integrated. Folded cascode circuit is used in the feedback path to maintain the common mode input value to a constant, so that the differential pair amplifies the differential signal. The gain of the comparator is achieved to be greater than 100 dB, with phase margin of 65°, common mode rejection ratio (CMRR) of above 70 dB and output swing from rail to rail. The circuit provides unity gain bandwidth of 5 GHz and is suitable for high sampling rate data converter circuits.</span></p>

High-Speed Hybrid-Logic Full Adder Using High-Performance 10-T XOR–XNOR Cell

The main aim of our work is to achieve low power, high speed design goals. The proposed hybrid adder is designed to meet the requirements of high output swing and minimum power. Performance of hybrid FA in terms of delay, power, and driving capability is largely dependent on the performance of XOR-XNOR circuit. In hybrid FAs maximum power is consumed by XOR-XNOR circuit. In this paper 10T XOR-XNOR is proposed, which provide good driving capabilities and full swing output simultaneously without using any external inverter. The performance of the proposed circuit is measured by simulating it in cadence virtuoso environment using 90-nm CMOS technology. This circuit outperforms its counterparts showing power delay product is reduced than that of available XOR-XNOR modules. Four different full adder designs are proposed utilizing 10T XOR-XNOR, sum and carry modules. The proposed FAs provide improvement in terms of PDP than that of other architectures. To evaluate the performance of proposed full adder circuit, we embedded it in a 4-bit and 8-bit cascaded full adder. Among all FAs two of the proposed FAs provide the best performance for a higher number of bits.

Design of Transfer-Gated CMOS Active Pixels Deploying Conventional PN-Junction Photodiodes

This paper presents a comparative study of six active pixel sensor (APS) schemes by means of simulations and experiments. The optical sensor used was a silicon photodiode with integrated electronics in a standard 0.35 µm CMOS technology. We analyzed how the transistor characteristics, such as channel resistance and leakage current, among others, can influence the APS response. Furthermore, we demonstrated how the choice of APS model affects sensor parameters such as output swing and fill factor, among others. The results presented and the understanding of the operational cycle of the CMOS transfer-gated APS aims at guiding better choices for different applications and the better transistor type in the project.

A Versatile Design of Low Power and High-Speed Operational Amplifier using Nano Scale Transistors

This paper illustrates the design of low power and high-speed operational Amplifier using Nanoscale Transistors. The proposed design introduces biasing block, for generating I=10uA for Channel length=180nm Technology. Adding biasing block to two-stages operational Amplifier current is constant i.e. there are no fluctuations in power supply, increase in bandwidth and power dissipation is less as compared the previous result. The design is simulated in p-spice tool and performed AC analysis. After analysis, the design achieved the parameter like Gain = 40db, Phase Margin=90º, Unity Gain Band Width=13MHz, Output Swing=0.1v to 1.7v and Power Dissipation=0.145mW.