Design of a New Low Power Fully Differential Amplifier with Settling Time Enhancement Characteristics

High performance of fully differential operational transconductance amplifier is designed and implemented using a 0.18-μm CMOS process. The implemented op-amp uses common mode feedback (CMFB) circuit operating in weak inversion region which does not affect other electrical characteristics due to eliminating common mode (CM) levels automatically leading to improve CM rejection ratio (CMRR) of the amplifier significantly. Moreover, the output stage has class-AB operation so that its current can be made larger due to increasing the output current dynamically using adaptive biasing circuit. Additionally, the AC currents of the active loads have been significantly reduced using negative impedances to increase the gain of the amplifier. The results show the GBW 2.3 MHz, slew rate 2.6 V/μs and 1% settling time 150 ns with a capacitive load of 15 pF. This amplifier dissipates only 6.2 μW from a 1.2 V power supply.

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Design of a Low-Power Rail-to-Rail CMOS Operational Amplifier

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.380-384.3304 ◽

2013 ◽

Vol 380-384 ◽

pp. 3304-3307

Author(s):

Yang Guang ◽

Bin Yu ◽

Huang Hai

Keyword(s):

Power Consumption ◽

Low Power ◽

Operational Amplifier ◽

Circuit Simulation ◽

Open Loop ◽

Cmos Process ◽

Output Stage ◽

Class Ab ◽

Op Amp ◽

Rail To Rail

In this paper, an operational amplifier with low-power consumption has been designed. Using the complementary differential pair for the input stage and the class AB structure for the output stage, the common-mode input range and output swing of the proposed circuit could achieved rail-to-rail. Based on TSMC 0.18μm CMOS process, using HSPICE 2008 software for circuit simulation, the results showed that the proposed op-amp has more than 100dB open loop gain, meanwhile the static power consumption is less than 300μw. The circuit's phase margin is 68 degrees, CMRR is 135dB and power supply rejection ratio is 63dB.

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Common-mode rejection ratio analysis of fully differential class AB two-stage op-amp with and without common-mode feedback circuit

2007 7th International Conference on ASIC ◽

10.1109/icasic.2007.4415691 ◽

2007 ◽

Cited By ~ 1

Author(s):

Kittipong Trijpech ◽

Ornanong Wiriyanuruknakorn ◽

Jirayuth Mahattanakul

Keyword(s):

Ratio Analysis ◽

Feedback Circuit ◽

Two Stage ◽

Common Mode ◽

Common Mode Rejection Ratio ◽

Class Ab ◽

Fully Differential ◽

Op Amp ◽

Rejection Ratio

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Implementation of Power-Efficient Class AB Miller Amplifiers Using Resistive Local Common-Mode Feedback

Journal of Low Power Electronics and Applications ◽

10.3390/jlpea11030031 ◽

2021 ◽

Vol 11 (3) ◽

pp. 31

Author(s):

Anindita Paul ◽

Mario Renteria-Pinon ◽

Jaime Ramirez-Angulo ◽

Ricardo Bolaños-Pérez ◽

Héctor Vázquez-Leal ◽

...

Keyword(s):

Current Efficiency ◽

Figure Of Merit ◽

Small Signal ◽

Common Mode ◽

Power Efficient ◽

Class Ab ◽

Op Amp ◽

Class A ◽

Wide Range ◽

Quiescent Current

An approach to implement single-ended power-efficient static class-AB Miller op-amps with symmetrical and significantly enhanced slew-rate and accurately controlled output quiescent current is introduced. The proposed op-amp can drive a wide range of resistive and capacitive loads. The output positive and negative currents can be much higher than the total op-amp quiescent current. The enhanced performance is achieved by utilizing a simple low-power auxiliary amplifier with resistive local common-mode feedback that increases the quiescent power dissipation by less than 10%. The proposed class AB op-amp is characterized by significantly enhanced large-signal dynamic, static current efficiency, and small-signal figures of merits. The dynamic current efficiency is 15.6 higher, the static current efficiency is 8.9 times higher, and the small-signal figure of merit is 2.3 times higher than the conventional class-A op-amp. A global figure of merit that determines an op-amp’s ultimate speed is 6.33 times higher than the conventional class A op-amp.

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Improved loop stability approach in fully differential operational transconductance amplifier with common‐mode feedback circuit

International Journal of Circuit Theory and Applications ◽

10.1002/cta.3218 ◽

2022 ◽

Author(s):

Reza Daie Koozehkanani ◽

Somaye Makouei ◽

Siroos Toofan

Keyword(s):

Feedback Circuit ◽

Operational Transconductance Amplifier ◽

Common Mode ◽

Fully Differential ◽

Transconductance Amplifier ◽

Loop Stability

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Fully Differential Class-AB OTA with Improved CMRR

Journal of Circuits System and Computers ◽

10.1142/s0218126617501699 ◽

2017 ◽

Vol 26 (11) ◽

pp. 1750169 ◽

Cited By ~ 1

Author(s):

Francesco Centurelli ◽

Pietro Monsurrò ◽

Gaetano Parisi ◽

Pasquale Tommasino ◽

Alessandro Trifiletti

Keyword(s):

Cmos Technology ◽

Current Mirror ◽

Differential Mode ◽

Common Mode ◽

Common Mode Rejection Ratio ◽

Class Ab ◽

Fully Differential ◽

Rejection Ratio ◽

Mode Behavior ◽

The Common

This paper presents a fully differential class-AB current mirror OTA that improves the common-mode behavior of a topology that presents very good differential-mode performance but poor common-mode rejection ratio (CMRR). The proposed solution requires a low-current auxiliary circuit driven by the input signal, to compensate the effect of the common-mode input component. Simulations in 40-nm CMOS technology show a net reduction of common-mode gain of more than 90[Formula: see text]dB without affecting the differential-mode behavior; a sample-and-hold amplifier exploiting the proposed amplifier has also been simulated.

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