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1.
A modified frequency compensation technique is proposed for low-power area-efficient three-stage amplifiers driving medium to large capacitive loads. Coined hybrid cascode feedforward compensation (HCFC), the total compensation capacitor is divided and shared between two internal high-speed feedback loops instead of only one loop as is common in prior art. Detailed analysis of this technique shows significant improvement in terms of bandwidth and stability. This is verified for a 1.2-V amplifier driving a 500-pF capacitive load in 90-nm CMOS technology, where HCFC reduces the total capacitor size and improves the gain-bandwidth by at least 30% and 40% respectively, compared to the prevailing schemes. 相似文献
2.
Single Miller capacitor frequency compensation technique for low-power multistage amplifiers 总被引:5,自引:0,他引:5
Due to the rising demand for low-power portable battery-operated electronic devices, there is an increasing need for low-voltage low-power low-drop-out (LDO) regulators. This provides motivation for research on high-gain wide-bandwidth amplifiers driving large capacitive loads. These amplifiers serve as error amplifiers in low-voltage LDO regulators. Two low-power efficient three-stage amplifier topologies suitable for large capacitive load applications are introduced here: single Miller capacitor compensation (SMC) and single Miller capacitor feedforward compensation (SMFFC). Using a single Miller compensation capacitor in three-stage amplifiers can significantly reduce the total capacitor value, and therefore, the overall area of the amplifiers without influencing their stability. Pole-splitting and feedforward techniques are effectively combined to achieve better small-signal and large-signal performances. The 0.5-/spl mu/m CMOS amplifiers, SMC, and SMFFC driving a 25-k/spl Omega///120-pF load achieve 4.6-MHz and 9-MHz gain-bandwidth product, respectively, each dissipates less than 0.42 mW of power with a /spl plusmn/1-V power supply, and each occupies less than 0.02 mm/sup 2/ of silicon area. 相似文献
3.
Pengfei Liao Ping Luo Shaowei Zhen Bo Zhang 《Circuits, Systems, and Signal Processing》2014,33(1):287-297
In this paper, a dual-Miller parallel compensation (DMPC) technique for low-power three-stage amplifier is presented with detailed theoretical analysis. A feedback network realized by capacitor and transconductance is added between the first and third stage, which improves significantly the performance when driving large capacitive loads. Furthermore, it is found to be stable for a wide range of capacitive loads. The proposed DMPC amplifier has been implemented in a 0.13-μm CMOS process and the chip area is 0.17×0.11 mm2. It achieves a 0.87 MHz gain-bandwidth product by consuming a total current of 41 μA. The DMPC amplifier is verified to be stable when the load capacitor ranges from 8 pF to 2 nF. 相似文献
4.
Song Guo Hoi Lee 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2009,56(10):758-762
This brief presents a single-capacitor active-feedback compensation (SCAFC) scheme for three-stage internal amplifiers driving small capacitive loads. The proposed SCAFC scheme can stabilize the three-stage amplifier by using only a single small-value compensation capacitor, thereby significantly reducing the amplifier implementation area. With the small-value compensation capacitor, the wide gain-bandwidth product (GBW) of the SCAFC amplifier can also be achieved under low-power conditions. Implemented in a standard 0.35-mum CMOS process, the proposed three-stage SCAFC amplifier achieves over 100-dB dc gain, 9.6-MHz GBW, and 6.1-V/mus average slew rate, by only dissipating 90 muW at 1.5 V and using a 1-pF compensation capacitor, when driving a 500-kOmega // 20-pF load. The proposed SCAFC amplifier experimentally improves both bandwidth-to-power and slew-rate-to-power efficiencies by more than 14 times and 9 times, respectively, as compared to a conventional three-stage nested-Miller-compensated amplifier. 相似文献
5.
提出了一种采用共栅频率补偿的轨到轨输入/输出放大器,与传统的Miller补偿相比,该放大器不仅可以消除相平面右边的低频零点,减少频率补偿所需要的电容,还可获得较高的单位增益带宽.所提出的放大器通过CSMC 0.6μm CMOS数模混合工艺进行了仿真设计和流片测试:当供电电压为5V,偏置电流为20μA,负载电容为10pF时,其功耗为1.34mW,单位增益带宽为25MHz;当该放大器作为缓冲器,供电电压为3V,负载电容为150pF,输入2.66 Vpp10kHz正弦信号时,总谐波失真THD为-51.6dB. 相似文献
6.
Hamed Aminzadeh 《Analog Integrated Circuits and Signal Processing》2018,95(2):271-282
Hybrid cascode feedforward compensation (HCFC) is an effective technique to stabilize nano-scale three-stage amplifiers driving ultra-large load capacitors. It divides the compensation capacitance and shares it between two high-speed local feedback loops embedded within the amplifier core. In this article, a systematic approach to analyze the transfer function and to evaluate the pole expressions of nano-scale HCFC amplifiers is presented. For the first time, the equivalent output impedance is successfully modeled to approximate the complicated transfer function of the HCFC amplifier without the need for lengthy pencil-and-paper calculations. An HCFC amplifier is designed and simulated in 90-nm CMOS technology, to verify the effectiveness of the new analytic approach. The simulated transfer function of the amplifier is almost identical to a calculated transfer function derived based on the new model. 相似文献
7.
Iman Chaharmahali Shahrooz Asadi Behnam Dorostkar Mosa malaknezhad bosra Mohammad Abedini 《Analog Integrated Circuits and Signal Processing》2017,93(1):61-70
A new method to compensate three-stage amplifier to drive large capacitive loads is proposed in this paper. Gain Bandwidth Product is increased due to use an attenuator in the path of miller compensation capacitor. Analysis demonstrates that the gain bandwidth product will be improved significantly without using large compensation capacitor. Using a feedforward path is deployed to control a left half plane zero which is able to cancel out first non-dominant pole. A three stage amplifier is simulated in a 0.18 μm CMOS technology. The purpose of the design is to compensate three-stage amplifier loading 1000 pF capacitive load. The simulated amplifier with a 1000 pF capacitive load is performed in 3.3 MHz gain bandwidth product, and phase margin of 50. The compensation capacitor is reduced extremely compared to conventional nested miller compensation methods. Since transconductance of each stage is not distinct, and it is close to one another; as a result, this method is suitable low power design methodology. 相似文献
8.
M. T. Tan P. K. Chan C. K. Lam C. W. Ng 《Circuits, Systems, and Signal Processing》2010,29(5):941-951
In this paper, we present an AC-boosting compensation topology with double pole-zero cancellation (ACBC-DPZ) for a multistage
amplifier driving a very large capacitive load. The proposed technique modifies the original AC-boosting compensation (ACBC)
topology to increase the power-bandwidth efficiency and reduce the size for the output power transistor and compensation capacitor.
Simulation results show that the ACBC-DPZ amplifier using a CSM 0.18 μm CMOS process can achieve a unity gain bandwidth of
14 MHz and an average slew rate of 3.88 V/μs at 1500 pF load. The amplifier dissipates 2.55 mW at a 1.8 V supply. 相似文献
9.
The sensitivity and accuracy of the conventional TVS technique is influenced by a capacitive current associated with the MOS capacitor which is superimposed on the ionic current. The authors present a new method and measuring circuit for automatic compensation of the capacitive current at the input of the current measuring instrument.<> 相似文献
10.
结合精确度和稳定性的要求提出了一种适合宽范围电容负载的CMOS运放.在多径嵌套式密勒补偿结构中加入一个抑制电容得到适合各种电容负载的稳定性.为了证实稳定性的提高对该结构进行了理论分析并计算得出数学表达式.基于这种新的频率补偿结构,利用CMOS 0.7μm工艺模型设计了样品芯片.测试结果表明:该运放可以驱动从100pF到100μF负载电容,直流增益为90dB,最小相位裕度为26°;该运放在100pF负载情况下单位增益带宽为1MHz,使用抑制电容仅为18pF. 相似文献
11.
Richards Gill G. Tan Owen T. Klinkhachorn Powsiri Santoso N. Iwan 《Industrial Electronics, IEEE Transactions on》1987,(2):266-270
A method is presented for finding the optimum LC combination for power factor compensation at linear loads in the presence of voltage source harmonics while the total voltamperes of the compensator capacitor and reactor is constrained. The end product is displayed in graph form where for any given compensator voltampere rating or cost, the maximum possible power factor and corresponding LC combination can be found. Examples are included showing that the cost of such an LC compensator may be less than that of a purely capacitive optimum compensator achieving the same power factor. 相似文献
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本文推导出高压钠灯线路补偿电容容量精算公式,分析讨论了高压钠灯电参数离散和寿命期间漂移将导致电路功率因数过补,线路呈现容抗性。指出高压钠灯线路补偿电容选择,应防止过多的负补。这对理解高压钠灯电路无功补偿和补偿电容量的选用,具有重要的指导意义。 相似文献
14.
Ka Nang Leung Mok P.K.T. Wing-Hung Ki Sin J.K.O. 《Solid-State Circuits, IEEE Journal of》2000,35(2):221-230
A novel damping-factor-control frequency compensation (DFCFC) technique is presented in this paper with detailed theoretical analysis, This compensation technique improves frequency response, transient response, and power supply rejection for amplifiers, especially when driving large capacitive loads, Moreover, the required compensation capacitors are small and can be easily integrated in commercial CMOS process. Amplifiers using DFCPC and nested Miller compensation (NMC) driving two capacitive loads, 100 and 1000 pF, were fabricated using a 0.8-μm CMOS process with Vtn=0.72 V and Vtp=-0.75 V. For the DFCFC amplifier driving a 1000-pF load, a 1-MHz gain-bandwidth product, 51° phase margin, 0.33-V/μs slew rate, 3.54-μs settling time, and 426-μW power consumption are obtained with integrated compensation capacitors. Compared to the NMC amplifier, the frequency and transient responses of the DFCFC amplifier are improved by one order of magnitude with insignificant increase of the power consumption 相似文献
15.
Multistage amplifiers are urgently needed with the advance in technology, due to the fact that single-stage cascode amplifier is no longer suitable in low-voltage designs. Moreover, the short-channel effects of the sub-micro CMOS transistor cause output-impedance degradation and hence the gain of an amplifier is reduced dramatically[1~6]. For multistage amplifiers, most of the compensation methods are based on pole splitting and pushing the right-half-plane zero to high frequencies or pole-ze… 相似文献
16.
CMOS low-voltage class-AB operational transconductance amplifier 总被引:2,自引:0,他引:2
The authors present a new low-voltage class-AB operational transconductance amplifier (OTA). The proposed OTA achieves a fast non slew-rate limited settling time with low power consumption. The circuit is power efficient when driving large capacitive loads. The OTA circuit is well suited for low-voltage low-power switched capacitor applications. Experimental results of the proposed circuit are included 相似文献
17.
G. Palumbo 《Analog Integrated Circuits and Signal Processing》1999,19(2):107-114
The aim of the paper is to discuss in detail the compensation of the current feedback amplifier (CFOA). The approach is suitable for a pencil-and-paper compensation and takes into account both resistive and capacitive feedback. The frequency limitation inside the CFOA and due to a load capacitor are also considered. The feature of the CFOA which can be simply compensated for when it is configured as a differentiator is also exploited. To validate the proposed strategies, Spice simulations were performed on the fundamental CFOA topologies, and some of them are included and discussed in the paper. 相似文献
18.
Design of low-power analog drivers based on slew-rate enhancement circuits for CMOS low-dropout regulators 总被引:2,自引:0,他引:2
Hoi Lee Mok P.K.T. Ka Nang Leung 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2005,52(9):563-567
Low-power analog driver based on a single-stage amplifier with an embedded current-detection slew-rate enhancement (SRE) circuit is presented. By developing a systematic way to design both the response time and optimal sizing of driving transistors in the SRE circuit, the SRE circuit can be controlled to turn on or turn off properly. In addition, the analog driver only dissipates low static power and its transient responses are significantly improved without transient overshoot when driving large capacitive loads. Implemented in a 0.6-/spl mu/m CMOS process, a current-mirror amplifier with the current-detection SRE circuit has achieved over 43 times improvement in both slew rate and 1% settling time when driving a 470-pF load capacitor. When the proposed analog driver is employed in a 50-mA CMOS low-dropout regulator (LDO), the resultant load transient response of the LDO has 2-fold improvement for the maximum load-current change, while the total quiescent current is only increased by less than 3%. 相似文献
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20.
为实现对传输线开关振荡器或振荡天线进行快速充电,以提高其耐压能力和产生高频振荡信号的能量效率,本文研制了一种基于Tesla变压器的电容储能型脉冲驱动源。本文首先介绍该驱动源的工作原理和运行过程,接着利用等效电路方法分析了关键电路参数对负载充电过程的影响,然后介绍该驱动源的具体工程设计,最后介绍该驱动源初步测试结果以及将其应用于变压器油在10 ns量级脉冲下击穿特性研究的实验情况。实验表明,输出火花开关在中储电容器充电电压为-191 kV导通时,通过电感对等效电容为15 pF的传输线充电电压峰值为-224 kV,电压上升时间约10 ns。研究结果表明本文研究的驱动源能够满足对传输线开关振荡器等电容负载进行快速充电至数百kV高压的应用需求。 相似文献