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

2021 ◽  
Vol 11 (3) ◽  
pp. 31
Author(s):  
Anindita Paul ◽  
Mario Renteria-Pinon ◽  
Jaime Ramirez-Angulo ◽  
Ricardo Bolaños-Pérez ◽  
Héctor Vázquez-Leal ◽  
...  

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.

Author(s):  
Anindita Paul ◽  
Jaime Ramirez-Angulo ◽  
Alejandro Diaz-Sanchez ◽  
Frank X. Li

2015 ◽  
Vol 24 (06) ◽  
pp. 1550078 ◽  
Author(s):  
Seid Jafar Hosseinipouya ◽  
Farhad Dastadast

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.


2014 ◽  
Vol 23 (05) ◽  
pp. 1450065 ◽  
Author(s):  
TOHID MORADI KHANESHAN ◽  
SAEED NAGHAVI ◽  
MOJDE NEMATZADE ◽  
KHAYROLLAH HADIDI ◽  
ADIB ABRISHAMIFAR ◽  
...  

A high-speed and high-accuracy continuous-time common-mode feedback block (CMFB) is presented. To satisfy speed and accuracy requirements, some modifications have been applied on differential difference amplifier (DDA) CMFB circuit. The proposed method is applied to a folded cascode op-amp with power supply of 3.3 V. In order to verify the proposed circuit, simulations are done in 0.35 μm standard CMOS technology. In the worst condition when the output common-mode (CM) voltage is initialized to VCC or GND, only 1.1 ns is required to set the output CM voltage on the desired level. Also in a wide range of input CM voltage variations, the deviation of the output CM voltage from reference voltage is less than 6 mV, so simulation results confirm the expected accuracy and speed while simultaneously the proposed CMFB circuit preserves other characteristics of DDA CMFB circuit such as unity gain frequency, 3-dB bandwidth, phase margin and linearity.


Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 805
Author(s):  
Shi Zuo ◽  
Jianzhong Zhao ◽  
Yumei Zhou

This article presents a low power digital controlled oscillator (DCO) with an ultra low power duty cycle correction (DCC) scheme. The DCO with the complementary cross-coupled topology uses the controllable tail resistor to improve the tail current efficiency. A robust duty cycle correction (DCC) scheme is introduced to replace self-biased inverters to save power further. The proposed DCO is implemented in a Semiconductor Manufacturing International Corporation (SMIC) 40 nm CMOS process. The measured phase noise at room temperature is −115 dBc/Hz at 1 MHz offset with a dissipation of 210 μμW at an oscillating frequency of 2.12 GHz, and the resulin figure-of-merit is s −189 dBc/Hz.


Author(s):  
Mizuki Motoyoshi ◽  
Kyoya Takano ◽  
Kosuke Katayama ◽  
Minoru Fujishima

2011 ◽  
Vol 20 (01) ◽  
pp. 1-13 ◽  
Author(s):  
CHENCHANG ZHAN ◽  
WING-HUNG KI

A CMOS low quiescent current low dropout regulator (LDR) with high power supply rejection (PSR) and without large output capacitor is proposed for system-on-chip (SoC) power management applications. By cascoding a power NMOS with the PMOS pass transistor, high PSR over a wide frequency range is achieved. The gate-drive of the cascode NMOS is controlled by an auxiliary LDR that draws only 1 μA from a small charge pump, thus helping in reducing the quiescent current. Adaptive biasing is employed for the multi-stage error amplifier of the core LDR to achieve high loop gain hence high PSR at low frequency, low quiescent current at light load and high bandwidth at heavy load. A prototype of the proposed high-PSR LDR is fabricated using a standard 0.35 μm CMOS process, occupying an active area of 0.066 mm2. The lowest supply voltage is 1.6 V and the preset output voltage is 1.2 V. The maximum load current is 10 mA. The measured worst-case PSR at full load without using large output capacitor is -22.7 dB up to 60 MHz. The line and load regulations are 0.25 mV/V and 0.32 mV/mA, respectively.


Author(s):  
Antonio J. Lopez-Martin ◽  
Jose Algueta ◽  
Lucia Acosta ◽  
Ramon G. Carvajal ◽  
Jaime Ramirez-Angulo

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