Current Controlled Transconductance Amplifier (Ccta) Using Advanced Design System

ISSN: 2395-1680 (ONLINE) ICTACT JOURNAL ON MICROELECTRONICS, JANUARY 2020, VOLUME: 05, ISSUE: 04 DOI: 10.21917/ijme.2020.0145 CURRENT CONTROLLED TRANSCONDUCTANCE AMPLIFIER (CCTA) USING ADVANCED DESIGN SYSTEM Mayuri A. Deshmukh and U.A. Kshirsagar Department of Electronics and Telecommunication Engineering, Sant Gadge Baba Amravati University, India Abstract IB1 IB2 Complementary Metal Oxide Semiconductor (CMOS) is a technology 2 2 used to produce integrated circuit. CMOS circuits are found in several types of electronic components, including microprocessors, batteries and digital camera image sensors. The MOS in CMOS refers to the Y Balanced Operational 0 transistor in a CMOS component called MOSFETs (metal oxide semiconductor field-effect transistors). In the project we are going to Differential Transconductance design novel CCCCTA, developed in CMOS technology using X Amplifier Amplifier Z Advanced Design System (ADS). Current conveyors are unity gain active building block having high linearity, wide dynamic range and Fig.1. Block diagram of current controlled current conveyor provide higher gain-bandwidth product. The current conveyors operate at low voltage supplies and consume less power. It has high input transconductance amplifier impedance, low output impedance, high CMRR and high slew rate. The current mode circuits such as Current conveyors have emerged as an 2. LITERATURE REVIEW important class of circuits in the field of analog electronics. The new structured CCCCTA the balanced differential-pair structure is used An amplifier which amplifies the difference between the two instead of the trans-linear structure as in the original CCCCTA and input signals is called differential amplifier. An operational our proposed block are the requirements of bias current which is used to control the parasitic resistance at the input current port and the amplifier or op-amp is a voltage amplifying device designed to number of MOSFETs. use with external feedback components such as resistors and capacitors between its output and input terminals. The operational amplifier (op-amp) has been the basic analog building blocks in Keywords: circuit design it has been evolved by introducing new analog COMS, MOSFTs, CCCCTA, Advanced Design System integrated circuit applications and by changing the analog circuit requirements [1]. The op-amp has several attractive features, such 1. INTRODUCTION as the differential pair input stage that is very good in rejecting common-mode signals. Moreover, this device only requires a The CMOS basically stand for complementary metal oxide single-ended output to provide a negative feedback and to drive a semiconductor, it is technology used to design analog circuits like load, and its implementation is simpler than a fully differential or data converters, image sensor etc. and also to construct ICs with balanced output. less complexity. MOS in CMOS refers to the transistor in a Sedra and Smith [3] [4] designed a programmable instruments CMOS component called MOSFETs (metal oxide semiconductor for their implementation in a system for computer controlled field-effect transistors). MOS is metal oxide semiconductor field experiments. His task was to design a voltage controlled effect transistor, is a type of insulated-gate field-effect transistor waveform generator, but at the end he designed a novel circuit, fabricated by controlled oxidation of a semiconductor, typically where the control variable was current and not voltage as it was Silicon. Each MOSFET includes two terminals (‘source’ and required. ‘drain’) and a gate, which is insulted from the body of the As an alternative for the voltage-mode, the Current Conveyor transistor. When enough voltage is applied between the gate and (CC) represented the building block designed for current signal body, electrons can flow between the source and drain terminals processing [3] and two years later, they published a second [2] [8]-[11]. version of a CC named Second Generation Current Conveyor An operational amplifier or op-amp is a voltage amplifying (CCII) [4], but any of these circuits became popular because of device designed to use with external feedback components such the introduction of the integrated op-amp at that time. The concept as resistors and capacitors between its output and input terminals. of the current conveyor (CC) and further developed to a second The operational amplifier (op-amp) has been the basic analog version. The CC is considered a general building block with building block in circuit design it has been evolved by introducing practical applications. new analog integrated circuit applications and by changing the The Third Generation CC or CCIII appeared in [5]. Its analog circuit requirements [1]. operation is very similar to the CCI, with the difference that the The current-mode design techniques offer voltage current through the Y-terminal flows in an opposite direction than independent and high performance analogue circuits like Current the current through the X-terminal. Conveyors (CCs). The purpose of this project is to design and A current controlled current conveyor trans-conductance synthesize a modified-version CCTA, which is newly named amplifier (CCCCTA) was first introduced by Siripruchyanun et current controlled current conveyor trans-conductance amplifier al. [6] as a new block to the current-mode building block for (CCCCTA). 845 MAYURI A DESHMUKH AND U A KSHIRSAGAR: CURRENT CONTROLLED TRANSCONDUCTANCE AMPLIFIER (CCTA) USING ADVANCED DESIGN SYSTEM analog signal processing which the parasitic resistance at input through which dopants are to be diffused. An oxidation layer is terminal and its output current gain can be controlled by input bias deposited over the wafer which acts as a shield for further currents. Its application can be tuned over a wide current range. It diffusion and metallization processes. In the gaps formed after can be used only one active element to perform applications such removal of excess metals terminal are formed for the as current-mode universal filter, grounded inductance simulator interconnections. and oscillator. CMOS Advantages: CMOS transistors are known for their A new active building block for analog signal processing, efficient use of electrical power. They require no electrical current namely, differential voltage current conveyor trans-conductance expect when they are changing from one state to another. amplifier (DVCCTA), was introduced. A voltage-mode Additionally, the complimentary semiconductors work together quadrature sinusoidal oscillator with independent current tunable to limit the semiconductor work together to limit the output frequency of oscillator is constructed. The DVCCTA has a trans- voltage. This result is a low-power design that gives off minimal conductance stage at its back end and hence it provides the feature heat. of electronic tuning to the circuit parameters, while also reducing CCCCTA is basically two stages differential amplifier which the number of resistors by one. The DVCCTA device is obtained accept input and produces an output which is proportional to the by cascading of the differential voltage current conveyor (DVCC) input. In the circuit we apply voltage and at the output we take with the operational trans-conductance amplifier (OTA) in currents. The amplifier which accept a voltages and produce monolithic chip for compact implementation of analog function currents, and current get controlled itself by amplifiers known as circuits. The DVCCTA is based on DVCC and consists of current controlled current conveyor transconductance amplifiers. differential amplifier, current mirrors, and trans-conductance The current controlled current conveyor trans-conductance amplifier [7]. amplifier (CCCCTA) as a new block to the current-mode building The original CCCCTA composed of the current-controlled block for analog signal processing which the parasitic resistance second generation current conveyor (CCCII) and an operational at input terminal and its output current gain can be controlled by trans-conductance amplifier (OTA) circuit. The CCCII is input bias currents. Its application can be tuned over a wide consisted of a trans-linear loop as the input section. Though the current range. It can be used as the only one active element to trans-linear structure is simple, the large offset voltage and the perform applications such as current-mode universal filter, poor voltage performance. In this project we design a new CMOS grounded inductance simulator and oscillator. The operation of CCCTA, namely the balanced differential-pair structure was CCCCTA can be given with following matrix equation, proposed by using the advanced system design software in new I y   0 0 0 0  I x  version which offers high-speed design platform and less complex      Vx    Rs 1 0 0 V y  circuit. The new structure reduces the requirements of large bias  (1) current and high power which are used in the trans-linear Iz   1 0 0 0 Vz  structure. It also requires fewer amounts of MOSFETs while the       I o   0 0  gm 0 Vo  performances are better. Vt Rx  c and (2) 3. CURRENT CONVEYOR TRANS- 2 Ib1 CONDUCTANCE AMPLIFIER Ib2 gm  (3) A device which accepts an input signal and produces an output 2Vt signal proportional to the input is called Amplifier. There are where, mg is the trans-conductance gain of the CCCCTA and TV variety of amplifiers available depending upon the natures of the is the thermal voltage. input and output signals. These types are the voltage amplifier, As Rx and gm are intrinsic resistance and trans-conductance, current amplifier, transconductance amplifier and trans-resistance respectively. amplifier. An amplifier which amplifies the difference between the two input signals is called differential amplifier. CMOS is a technology used to produce integrated circuit. CMOS circuits are found in several types of electronic components, including microprocessors, batteries and digital camera image sensors. The CMOS fabrication process flow is conducted using some basic fabrication First we have to choose a substrate as a base for fabrication. The selective diffusion of n- type impurities is accomplished using SiO2 as a barrier which protects portions of the wafer against contamination of the substrate. The selection etching, the SiO2 layer is subjected to the photolithography process. In this process, the wafer is coated with a uniform film of a photosensitive emulsion. Masking is the continuation of the photolithography process. The mask is Fig.2. Current conveyor trans-conductance amplifier removed and the unexposed region of photoresist is dissolved by developing wafer. The wafer is immersed is an etching solution The CMOS CCCCTA consists of two building blocks: of hydrofluoric acid, which removes the oxide from the areas 846 ISSN: 2395-1680 (ONLINE) ICTACT JOURNAL ON MICROELECTRONICS, JANUARY 2020, VOLUME: 05, ISSUE: 04 3.1 A BALANCED DIFFERENTIAL-PAIR CCTA MOSFETs Mn8, Mn9 working as differential pair and Mp5, Mp6 CIRCUITS working as current mirror with B2 and I is the 2nd input bias current. The output resistance at O terminal is, A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the inputs. Operational amplifier or op-amp is a differential amplifier with very differential-mode gain, very high input impedance, and low output impedance. The circuit consists of a balanced differential- pair structure as the input stage which is realized using MOSFETs Mp1, Mp2 and Mn1, Mn2. The output current at Z terminal is conveyed from the input current at X terminal is realized using MOSFETs Mp3, Mp4 and Mn3, Mn4. The bias circuit is realized using current mirror which composed of MOSFETs Mn5 - Mn7. The input and output resistances looking into the X terminal and Z terminal are formulated as: 1 1 Rx   (4) gmD W Ib1nCox D LD Fig.4. Operational Transconductance Amplifier circuit where, IB1 is the 1st input bias current. Advantages of operational transconductance amplifier are as 1 follows, Rz  (5) g ds m  g ds m • Wide bandwidth • High slew rate • High transconductance • Low quiescent current A balanced differential pair and operational transconductance amplifier provide some advantages thus they are used in various circuit design such as, • Current amplifier, • Voltage to current convertor • Current differentiator /integrator, • Current summer, • Instrumentation amplifier • In filters designing etc. 4. PERFORMANCE SIMULATION Fig.3. A balanced differential-pair CCTA circuit For designing and examine the performance of current controlled transconductance amplifier we used the advanced Advantages of differential pair circuits are as follows design system. Advanced design System (ADS) is an electronic • High differential voltage gain design automation software system produced by keysight EEs of EDA, a division of keysight technologies. Keysight ADS supports • Low common mode gain every step of design process-schematic capture, layout, design • High CMRR rule checking, frequency domain and time domain circuit • Two input terminals simulation and electromagnetic field stimulation. • High input impedance ADS have advanced capabilities for the design process, before fabrication of wireless components such as power amplifiers and • Large bandwidth RF front-end modules. It allows to creates and analyze circuit and • Low offset voltages and currents. system designs and display simulation data. While design in ADS • Low output impedance. we have to select MOSFETs with some selective parameters and they are as given in the Table.1. Here, MOSFETs of trans-linear 3.2 AN OPERATIONAL TRANS-CONDUCTANCE type is used. AMPLIFIER (OTA) The operational transconductance amplifier is amplifier whose differential input voltage produces an output current. 847 MAYURI A DESHMUKH AND U A KSHIRSAGAR: CURRENT CONTROLLED TRANSCONDUCTANCE AMPLIFIER (CCTA) USING ADVANCED DESIGN SYSTEM Table.1. Transistors width and lengths Width Length Transistors (µm) (µm) NMOS 260µm 20µm [Mp1,Mp2, Mp3,Mp4], [Mp5, Mp6] PMOS 260µm 10µm [Mp1,Mp2,Mp3,Mp4,Mp5,Mp6,Mn7],[Mn8,Mn9] The process of design circuits in software are as follows, 1. Open the software and select the option as per requirement. (b) 2. Create a new workspace and after that new window get opened. Fig.7. Transfer analysis of CCCCTA 3. Design new schematic window. 4.1.1 Applications of CCCCTA: 4. After that new window page open in which we have to deign circuits. CCCCTA are used in following applications and they are, 5. Design and stimulate the circuit. • Video/Broadband equipments • Communication equipments • High speed data acquisition • Wideband LED drivers • Control loop amplifiers • Wideband active filter, • Line drivers • Instrumentation amplifiers etc. 5. CONCLUSION In these a new structure of current controlled transconductance amplifier has been given. The whole current transconductance amplifier design by using CMOS technology and stimulated in advanced design system (ADS) 2020 of keysight technology by considering the parameters for MOSFETs and considering 1.5 Fig.5. Design circuit of differential balanced amplifier stage voltage supply during stimulations. Advantages of proposed circuits are the less number of numbers of MOSFETs, so it has lower power consumption. The proposed circuit used where we have to reduce the requirement of power i.e. current with reduce size and cost effective. REFERENCES [1] C. Toumazou, G. Moschytz and B. Gilbert, “Trade in Fig.6. Simulation results Analog Circuit Design the Designer’s Companion”, Springer, 2002. [2] Warisa Thitopakarn, Roungsan Chaisricharoen, Boonruk Chipipop and Kohji Higuchi, “Novel CMOS Current- Controlled Current Conveyor Transconductance Amplifier (CCCCTA)”, Proceedings of 10th International Symposium on Communications and Information Technologies, pp. 21- 29, 2010. [3] K.C. Smith and A. Sedra, “The Current Conveyor-A New Circuit Building Block”, Proceedings of the IEEE, Vol. 56, No. 8, pp. 1368-1369, 1968. [4] A. Sedra and K.C. Smith, “A Second-Generation Current (a) Conveyor and Its Applications”, IEEE Transactions on Circuits Theory, Vol. 17, No. 1, pp. 132-134, 1970. 848 ISSN: 2395-1680 (ONLINE) ICTACT JOURNAL ON MICROELECTRONICS, JANUARY 2020, VOLUME: 05, ISSUE: 04 [5] A. Fabre, “Third-Generation Current Conveyor: A New [8] U.A. Bakshi and A.P. Godse, “Linear Integrated Circuits Helpful Active Element”, Electronics Letters, Vol. 31, No. and Applications”, Technical Publications, 2010. 5, pp. 338-339, 1995. [9] T. Kurashina, S. Ogawa and K. Watanabe, “A CMOS Rail- [6] Montree Siripruchyanun and Winai Jaikla, “Current to-Rail Current Conveyor and Its Applications to Current- Controlled Current Conveyor Transconductance Amplifier Mode Filters”, IEICE Transactions on Fundamentals of (CCCCTA): A Building Block for Analog Signal Electronics Communications and Computer Sciences, Vol. Processing”, Proceedings of International Symposium on 86, No. 6, pp. 1445-1450, 2003. Communications and Information Technologies, pp. 1-6, [10] R. Chaisricharoen, B. Chipipop and B. Sirinaovakul, 2007. “CMOS CCCII: Structures, Characteristics, and [7] Neeta Pandey and Sajal K. Paul, “VM and CM Universal Considerations”, AEU International Journal of Electronics Filters Based on Single DVCCTA”, Active and Passive and Communications, Vol. 64, No. 6, pp. 540-557, 2010. Electronic Components, Vol. 2011, pp. 1-7, 2011. [11] R. Gregorian, “Introduction to CMOS Op-Amp and Comparators”, John Wiley and Sons, 1999. 849