Leila Safari

CMOS FIRST-ORDER CURRENT-MODE ALL-PASS FILTER WITH ELECTRONIC TUNING CAPABILITY AND ITS APPLICATIONS

In this paper, a novel first-order current-mode (CM) electronically tunable all-pass filter including one grounded capacitor and two dual-output current followers (DO-CFs) is presented. The used DO-CFs are implemented using only 10 MOS transistors granting the proposed CM all-pass filter extremely simple structure. The proposed filter is suitable for integrated circuit (IC) fabrication because it employs only a grounded capacitor and is free from passive component matching conditions. Interestingly the introduced configuration uses minimum number of components compared to other works. It also offers other interesting advantages such as, alleviating all disadvantages associated with the use of resistors, easy cascadability and satisfies all technology requirements such as small sizing, simple realization, low voltage and low power operation. Additionally, the circuit parameters can be easily set by adjusting control voltages. Most favorably, the proposed CM all-pass filter can be simply used as a voltage-m...

A New Transresistance-Mode Instrumentation Amplifier with Low Number of MOS Transistors and Electronic Tuning Opportunity

In this paper, the simplest possible electronically adjustable transresistance-mode (TRM) instrumentation amplifier (IA) using only eight MOS transistors is presented. Extremely simple structure of...

A high CMRR low power fully differential Current Buffer

In this paper a low power fully differential current buffer is introduced which performs high CMRR exploiting a novel method to alleviate common mode gain. The proposed current buffer is designed and simulated with HSPICE in 0.18μm CMOS process and supply voltage of ±0.75 V. The simulation results show an 8.48 Ω input resistance, 98 dB CMRR, 369 MHz bandwidth and power dissipation of 135μW. The corner case simulation has been done which shows an acceptable performance for the proposed buffer in all situations. The proposed circuit tends to be the fundamental block of a new family of electronic differential topologies greatly capable to be much further improved and utilized.

A Low-Voltage Low-Power Resistor-Based Current Mirror and Its Applications

In this paper, a CMOS resistor-based current mirror (RBCM) aimed to be used in low-voltage applications is presented. The main features of the proposed current mirror are very low input voltage requirement (a few mV), low output voltage requirement, high output impedance and simple circuitry. The core structure of the proposed RBCM consists of three transistors (excluding bias circuitry) and two low value grounded resistors. The proposed circuit alleviates the need for cascode structures which are conventionally used to boost the output impedance and linearity. SPICE simulations using 0.18μm CMOS technology parameters under supply voltage of 0.9V are reported which show input and output voltage requirements of 40mV and 0.1V respectively, low THD of 1.2%, Rin of 496Ω, Rout of 1MΩ, −3dB bandwidth of 181MHz and power dissipation of 154μW. A high CMRR differential amplifier and a high performance current difference circuit as applications of the proposed RBCM are given. The proposed RBCM is very useful in tackling restrictions of modern technologies such as reduced supply voltage and transistors low intrinsic output impedance.

A simple low voltage, high output impedance resistor based current mirror with extremely low input and output voltage requirements

A New CMOS resistor based current mirror with extremely low voltage requirement at input (in the range of a few mV) and output voltage requirement of about one Vds is presented. The proposed structure combines the advantages of wide input swing, wide output swing, large output impedance, low input impedance and high linearity altogether, which make it attractive for high performance low-voltage and low power applications. Pspice simulations show a very low THD of -42.2dB from a single 0.9V supply in 0.18μm, input impedance of 239Ω, output impedance of 1.2MΩ and power dissipation of only 180μW. Interestingly, the input and output voltage requirements are only 10mV and 0.1V respectively.

A novel fully differential current buffer with ultra low input impedance, high CMRR, low power and low voltage

In this paper a novel fully differential current buffer is introduced. Its novelty originates from two things; 1) special technique applied to reject the input common mode signal and provide high CMRR of 109dB and higher, 2) deliberately arrangement of virtual grounded inputs by a very small but powerful circuit that admirably granted the block the ultra low input impedance of 38mΩ. Furthermore, it consumes low power of 105μW and operates with low voltage supplies of ±0.75V, due to its compact structure. These superb results are verified by HSpice simulation using 0.18μm CMOS technology of TSMC. Monte Carlo simulation of the proposed buffer is also examined that proved its robustness against technology Process (mismatches).

A New Low Voltage Low Power Fully Differential Current Buffer and Its Application as a Voltage Amplifier

In this paper a novel low voltage low power fully differential current buffer with high CMRR is introduced. The proposed current buffer is designed and simulated with HSPICE in TSMC 0.18µm CMOS process and supply voltage of ±0.75V. The simulation results show 39.5Ω and 5.64KΩ differential mode and common mode input resistances respectively. The differential mode input impedance is 142.7 times smaller than the common mode one which is a unique feature. This result is quite significant when it is considered that in the conventional current buffers differential mode input resistance is equal to common mode one. The proposed current buffer exhibits a CMRR of 72.2dB and consumes only 83.9µW. PSRR+ and PSRR- are 160dB and 120dB respectively which make the proposed current buffer very suitable for mixed mode designs. Application of the proposed current buffer as a voltage amplifier is also presented which benefits from the outstanding property of independency of gain from related -3dB bandwidth.

New ECCII-based electronically controllable current-mode instrumentation amplifier with high frequency performance

In this paper, a new electronically controllable current-mode instrumentation amplifier (CMIA) is presented. The proposed CMIA is based on only two electronically tunable second-generation current conveyors (ECCIIs). It does not need any passive element which makes it highly suitable for integration. More interestingly, high CMRR is achieved without the need for matching between active elements. Its input and output signals are current and it enjoys low input and high output impedances, respectively. Due to the inefficiency of the existing ECCIIs, a new ECCII circuit is also designed to be used in the proposed CMIA structure. PSPICE simulation results using 0.18μm TSMC CMOS technology and supply voltage of ±0.9V, shows CMRR of 42dB and fixed −3dB bandwidth of 68MHz for differential-mode gain ranging from 0dB to 27dB.

High CMRR low-voltage low power current output stage with a novel CMFB

In this paper, a low voltage low power (LPLV) current output stage (COS) with high CMRR is proposed. A novel common mode feedback (CMFB) technique is exploited to provide high CMRR. That is done by summing the main common mode signal and its opposite polarity one which provides over 112dB of CMRR in 0.18µm CMOS technology of TSMC. The circuit operates with very low supply voltages of ±0.5Vand consumes only 145µW power which show good improvement compared to other similar stages in literatures. Monte Carlo simulation of CMRR is also performed and shows its sufficient robustness against mismatches.