Compact Power-Efficient Static Class-AB Miller Op-amp with Enhanced Large and Small Signal Figures of Merit

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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Power efficient fully differential low-voltage two stage class AB/AB op-amp architectures

2004 IEEE International Symposium on Circuits and Systems (IEEE Cat. No.04CH37512) ◽

10.1109/iscas.2004.1328299 ◽

2004 ◽

Cited By ~ 5

Author(s):

S. Thoutam ◽

J. Ramirez-Angulo ◽

A. Lopez-Martin ◽

R.G. Carvajal

Keyword(s):

Low Voltage ◽

Two Stage ◽

Power Efficient ◽

Class Ab ◽

Fully Differential ◽

Op Amp ◽

Stage Class

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135GHz CMOS small-signal amplifier with power-efficient bias method

2013 Asia-Pacific Microwave Conference Proceedings (APMC) ◽

10.1109/apmc.2013.6695142 ◽

2013 ◽

Author(s):

Mizuki Motoyoshi ◽

Kyoya Takano ◽

Kosuke Katayama ◽

Minoru Fujishima

Keyword(s):

Small Signal ◽

Power Efficient ◽

Signal Amplifier

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

Journal of Circuits System and Computers ◽

10.1142/s0218126615500784 ◽

2015 ◽

Vol 24 (06) ◽

pp. 1550078 ◽

Cited By ~ 1

Author(s):

Seid Jafar Hosseinipouya ◽

Farhad Dastadast

Keyword(s):

High Performance ◽

Settling Time ◽

Cmos Process ◽

Output Stage ◽

Common Mode ◽

Class Ab ◽

Fully Differential ◽

Op Amp ◽

Transconductance Amplifier ◽

Adaptive Biasing

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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A Positive Feedback-Based Op-Amp Gain Enhancement Technique for High-Precision Applications

Journal of Circuits System and Computers ◽

10.1142/s0218126620502205 ◽

2020 ◽

Vol 29 (14) ◽

pp. 2050220

Author(s):

Rajasekhar Nagulapalli ◽

Khaled Hayatleh ◽

Steve Barker

Keyword(s):

Positive Feedback ◽

Cmos Technology ◽

Voltage Gain ◽

Silicon Area ◽

Power Efficient ◽

Enhancement Technique ◽

Op Amp ◽

Gain Enhancement ◽

Pvt Variations ◽

Boosting Technique

A power-efficient, voltage gain enhancement technique for op-amps has been described. The proposed technique is robust against Process, Voltage and Temperature (PVT) variations. It exploits a positive feedback-based gain enhancement technique without any latch-up issue, as opposed to the previously proposed conductance cancellation techniques. In the proposed technique, four additional transconductance-stages (gm stages) are used to boost the gain of the main gm stage. The additional gm stages do not significantly increase the power dissipation. A prototype was designed in 65[Formula: see text]nm CMOS technology. It results in 81[Formula: see text]dB voltage gain, which is 21[Formula: see text]dB higher than the existing gain-boosting technique. The proposed op-amp works with as low a power supply as 0.8[Formula: see text]V, without compromising the performance, whereas the traditional gain-enhancement techniques start losing gain below a 1.1[Formula: see text]V supply. The circuit draws a total static current of 295[Formula: see text][Formula: see text]A and occupies 5000[Formula: see text][Formula: see text]m2 of silicon area.

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Small-signal analysis of fully-differential closed-loop op-amp circuits with arbitrary external impedance elements

IET Circuits Devices & Systems ◽

10.1049/iet-cds.2010.0401 ◽

2011 ◽

Vol 5 (5) ◽

pp. 371 ◽

Cited By ~ 1

Author(s):

J.J. Cooley ◽

A.-T. Avestruz ◽

S.B. Leeb

Keyword(s):

Signal Analysis ◽

Closed Loop ◽

Small Signal ◽

Fully Differential ◽

Op Amp ◽

Small Signal Analysis

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Realization of a 30-W highly efficient and linear reconfigurable dual-band power amplifier using the continuous mode approach

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078713000937 ◽

2013 ◽

Vol 6 (2) ◽

pp. 115-128 ◽

Cited By ~ 4

Author(s):

Vincenzo Carrubba ◽

Stephan Maroldt ◽

Markus Mußer ◽

Herbert Walcher ◽

Friedbert Van Raay ◽

...

Keyword(s):

Power Amplifier ◽

Continuous Wave ◽

Second Harmonic ◽

Power Level ◽

Dual Band ◽

Power Efficient ◽

Frequency Bands ◽

Class Ab ◽

Output Performance ◽

Band Power

This paper presents the design methodology and the realization of a highly linear and power-efficient reconfigurable dual-band amplifier based on the continuous/Class-ABJ approach. The Class-ABJ theory allows presenting different reactive solutions on both fundamental and second harmonic terminations compared with the standard Class-AB mode. Despite the various terminations, a constant optimum output performance in terms of power, gain, and efficiency can still be achieved. The output impedances are then translated into frequency thus allowing the realization of broadbandpower amplifiers(PAs) at high-power level of 30 W. In this work, the Class-ABJ broadband approach will be used for the realization of a reconfigurable dual-band power amplifier operating in the two frequency bands 2.1–2.2 and 2.5–2.6 GHz. Continuous wave (CW) measurements on the realized PA show power and efficiency greater than 17 W and 55% in the two frequency bands with peak values up to 30 W and 63.7%. Indeed, it is shown that such novel modes can be predistorted and therefore the linearity requirement can also be met.

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