共查询到19条相似文献,搜索用时 93 毫秒
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为了解决线性跨导输入范围有限的问题,提出了一种具有宽线性输入范围的高线性运算跨导放大器(Operational Transconductance Amplifier,OTA),可有效适用于包括低频连续时间滤波器在内的电流模式电路。该OTA利用源极退化和辅助差分结构,通过减少失真分量来显著增加线性范围。此外还利用该OTA实现了一种二阶全差分滤波器;采用SCL180 nm CMOS工艺进行了设计和仿真。实验结果表明,相比于其他设计方法,该OTA和滤波器具有更宽的线性范围和更低的失真。对于1 MHz信号频率、600 mVP-P的输入,该OTA的三次谐波失真分量和互调失真分量分别为-74.8 dB和-76.1 dB,线性范围为0.9V(1%跨导变化)。对于300 mVP-P、10 kHz输入,该滤波器的三次谐波失真分量和互调失真分量分别为-69.75 dB和-65.2 dB。 相似文献
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设计了一款改进的基于交叉耦合结构的跨导运算放大器(OTA)。设计和分析过程中依据严格的理论推导,新结构在高输入摆幅下线性度得到明显优化,当输入为2V@5MHz正弦波时,谐波总量从0.7%降至0.3%,并成功应用于包络跟踪功率放大器。仿真测试基于CSMC 0.5μm CMOS工艺,仿真结果表明二到五次谐波分量总和从传统OTA的-40 dB降低到-52 dB,同时在VSS系统联合仿真平台上,用15 MHz带宽的OFDM调制信号测试星座图,其聚敛性也得到了明显优化,矢量误差从4.7%降至3.6%。 相似文献
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随着低电压系统的广泛应用和对性能要求的提高,要求输入跨导放大器具有宽输入电压动态范围。文章论述了一种较为简单的电路可以实现宽摆幅恒定跨导,包括主跨导放大器、负跨导放大器和求和电路。电路模拟证明这种简单结构具有很高的共模电压输入范围和很低的谐波失真。 相似文献
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采用华虹NEC 0.35um BCD工艺,设计并实现了一种可作DC-DC转换器控制芯片内部误差放大器的CMOS跨导放大器,该跨导放大器采用源极电阻跨接式负反馈技术提高跨导的线性度、采用双折叠式差分对结构实现共模输入范围轨至轨(rail-to-rail)、采用低功耗偏置推挽(push-pull)输出结构提高输出驱动负载的能力,整体电路具有结构紧凑、功耗低、线性度高等特点。仿真结果表明:在5.25V电源电压下,驱动1pf负载,直流增益可以达到68.2db,功耗708uw,100kHz下跨导的三次谐波失真HD3达到-56db。 相似文献
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《电子元件与材料》2016,(4):61-65
基于TSMC 180 nm工艺库,设计了一款低电压高线性度的电流差分跨导放大器(CDTA,在电路的设计中采用了具有自适应尾电流源偏置结构来提高其线性度。利用Cadence和Spectre软件进行电路设计与仿真。结果显示,在系统典型应用环境下,当Z端的电压在–1.4~+1.3 V变化时,X端的电流变化范围达到–100~+100μA;I_Z/I_P,I_Z/I_N的–3 d B带宽分别为230.5 MHz和236.4 MHz;Z端和X端阻抗分别为8 M?和2.3 M?。该CDTA具有低输入阻抗和高输出阻抗、低电压、高线性度的良好性能,已用于增益可调的有源滤波器设计。 相似文献
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基于吉尔伯特单元,设计了一款高线性度低失真模拟乘法器.通过在输入端加入一个电平移位器,使线性输入范围增大,并由一个跨导运算放大器给吉尔伯特单元提供尾电流,有效地改善了乘法器的线性特性.设计的电路基于UMC 0.6μm BCD工艺,采用HSPICE进行仿真验证.结果表明,该乘法器的线性输入范围可达±2 V,非线性误差和总谐波失真分别小于1%和0.3%,适用于要求输入范围大、非线性误差小及失真低的系统. 相似文献
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针对现有的线性跨导运算放大器存在的主要问题设计了一个新的线性OTA,模拟结果表明在输入电压从-0.8V到+0.8V变化时,其线性误差小于±1.5%。 相似文献
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Maithil Pachchioar 《电子设计技术》2008,(4)
2008年4月采用电压反馈放大器(VFA)来设计一个优质的电流到电压(跨导放大器)转换器是一项重大的挑战。理论上,一个光电二极管当曝露在光线中时可产生一个电流或电压输出,而跨导放大器(TIA)便是将这个很弱的电流转换成一个可用的电压信号,通常跨导放大器均需经过补偿才能正常工作。 相似文献
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CMOS浮地电源交叉耦合运算跨导放大器 总被引:1,自引:0,他引:1
提出了一种高线性度运算跨导放大器.该电路采用CMOS对管和浮地电源交叉耦合作输入级。对所描述的电路进行了理论分析和计算机模拟.结果表明,在传输特性的非线性误差不大于1%时,电路的差动输入电压范围可达±2.8V。 相似文献
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介绍了一种低电压、高效率的全差分自适应偏置跨导运算放大器。采用甲乙类的差分结构作为输入级,包含一个本地共模反馈结构(LCMFB),用以提供额外的电流自举,同时也提高其增益带宽积(GBW)和达到近乎理想的电流效率。采用TSMC 0.25μm标准工艺,实现全差分超级自适应运算放大器。为了比较,同时实现了传统的跨导运放和单端输出超级自适应运放。在10μA偏置电流和2 V工作电压下,与传统结构相比,超级自适应运放的转换速率提升了200倍,增益带宽积提高了4倍;而其全差分结构相对单端结构在几乎所有性能提升一倍的同时,还获得很好的共模抑制比和电源抑制比。 相似文献
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Rahul Sarpeshkar Richard F. Lyon Carver Mead 《Analog Integrated Circuits and Signal Processing》1997,13(1-2):123-151
The linear range of approximately ±75mV of traditional subthreshold transconductance amplifiers istoo small for certain applications—for example, for filtersin electronic cochleas, where it is desirable to handle loudsounds without distortion and to have a large dynamic range.We describe a transconductance amplifier designed for low-power(< 1 µW) subthreshold operation with a wideinput linear range. We obtain wide linear range by widening thetanh, or decreasing the ratio of transconductance to bias current,by a combination of four techniques. First, the well terminalsof the input differential-pair transistors are used as the amplifierinputs. Then, feedback techniques known as source degeneration(a common technique) and gate degeneration (a new technique)provide further improvements. Finally, a novel bump-linearizationtechnique extends the linear range even further. We present signal-flowdiagrams for speedy analysis of such circuit techniques. Ourtransconductance reduction is achieved in a compact 13-transistorcircuit without degrading other characteristics such as dc-inputoperating range. In a standard 2 µm process,we were able to obtain a linear range of ±1.7V.Using our wide-linear-range amplifier and a capacitor, we constructa follower–integrator with an experimental dynamic rangeof 65 dB. We show that, if the amplifier's noise is predominantlythermal, then an increase in its linear range increases thefollower–integrator'sdynamic range. If the amplifier's noise is predominantly 1/f,then an increase in its linear range has no effect on thefollower–integrator'sdynamic range. To preserve follower–integrator bandwidth,power consumption increases proportionately with an increasein the amplifier's linear range. We also present data for changesin the subthreshold exponential parameter with current leveland with gate-to-bulk voltage that should be of interest to alllow-power designers. We have described the use of our amplifierin a silicon cochlea [1, 2]. 相似文献
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Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product (GBW), slew rate (SR), and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier (OTA) with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5 m complementary metal oxide semiconductor (CMOS) process. The simulation results show that the SR is 4.54 V/s, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%. 相似文献
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