New simple square-rooting circuits based on translinear current conveyors

Two new square-rooting circuits, based on second-generation current-controlled current conveyors (CCCIIs), are presented. The first square-rooting circuit consists of two CCCIIs, one current-controlled resistor and two grounded resistors. The input signal of the first circuit is a voltage, and output is the voltage proportional to the square root of input voltage. The second one consists of two CCCIIs and a current-controlled resistor. In the second circuit, the input signal is a current, and output is the current proportional to the square root of input current. Each circuit realizes by using a current-mode technique; hence the proposed square-rooting circuits are simple circuitry, wide dynamic range and wide bandwidth. The proposed square-rooting circuits were confirmed by using PSPICE simulation.     

Floating Immittance Function Simulator and Its Applications

A new floating immittance function simulator circuit is proposed using two different active elements, a dual-output second generation current conveyor (DO-CCII) and an operational transconductance amplifier (OTA). The presented circuit can realize a positive and negative floating inductor, capacitor and resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable for fully integrated circuit design. The circuit does not require any component matching conditions, and it has a good sensitivity performance with respect to tracking errors. Moreover, the proposed positive and negative inductance, capacitor and resistor simulator can be tuned electronically by changing the biasing current of the OTA or can be controlled through the grounded resistor or capacitor. The proposed floating inductor simulator circuit is demonstrated by using a SPICE simulation for 0.35 μm TSMC CMOS technology. The proposed circuit consumes an average power of 1 mW using ±1.5 V supply voltages.     

Electronically tunable mutually coupled circuit using only two active components

A new circuit for realisation of the mutually coupled circuit, which is also called the synthetic transformer, is proposed. The proposed circuit uses two current controlled current conveyor transconductance amplifiers (CC-CCTAs), one grounded resistor and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the CC-CCTAs. It uses two grounded capacitors which are suitable from the point of integrated circuit implementation. It has a good sensitivity performance with respect to tracking errors and passive components. The validity of the proposed circuit is demonstrated by PSpice simulations.     

Novel first order all-pass sections using a single CCIII

Two novel first order voltage-mode all-pass sections using a single third generation current conveyor (CCIII) are given. In addition the first circuit uses three resistors and one capacitor and the second circuit which is derived from the first circuit uses two resistors and one capacitor. A current-mode first order all-pass section requiring one capacitor and one resistor is also proposed. SPICE simulation results are incorporated to verify the theory.     

LCoS伽马校正电路的研究

提出了一种应用于硅上液晶(LCoS)的伽马校正电路.双梯电阻数模转换器是伽马校正电路的一个重要组成部分.双梯电阻数模转换器由粗分电阻级和细分电阻级组成,其最大优点是占用版图面积小.提出的10位双梯电阻数模转换器仅由80个电阻、2个4-16译码器、1个2-4译码器和一些开关组成,供电电压是5 V.该数模转换器由0.35μm CMOS工艺实现.后仿真结果表明,数模转换器的微分非线性和积分非线性分别小于±0.5 LSB和±0.4 LSB.最后,对伽马校正电路进行了仿真,给出了伽马校正电路输出的液晶伽马校正曲线,仿真结果表明伽马校正电路能够满足LCoS显示系统的要求.

Abstract：

One gamma correction circuit for liquid crystal on silicon (LCoS) is proposed. Dual ladder resistor DAC (Digital to Analog Converter) is one of main components of the gamma correction circuit. Dual ladder resistor DAC consists of coarse resistor stage and fine resistor stage. The most advantage of the DAC is that its layout area is small. In this paper, the proposed 10-bit dual ladder resistor DAC only requires eighty resistors, two 4-to-16 decoders, one 2-to-4 decoder and some switches with a supply voltage of 5 V. This DAC is implemented by 0.35 m CMOS technology. The post simulation results that its differential non-linearity (DNL) and integral non-linearity (INL) are less than 0. 5 LSB and 0. 4 LSB, respectively. Meanwhile, the gamma correct circuit was simulated, and the gamma correction curve of liquid crystal is given. Simulation results show that the gamma correction circuit can meet the requirements of LCoS display system.     

Tunable frequency versatile filters implementation using minimum number of passive elements

Two new universal active current-mode filters are proposed, one topology of which is with three inputs and one output, the other prototype is with single input and three outputs counterpart. One proposed circuit employs two current conveyors, two grounded capacitors and two resistors, wherever the other proposed circuit employs two current conveyors, two grounded capacitors and two multi-input, multi-output Operational Transconductance Amplifiers(OTA) as variable resistor for tuning the cutoff frequency of realized filters. Without changing the passive elements, the proposed circuits employ features of multifunctional, convenient for integration, low sensitivities and simple in structure.     

Novel voltage/current-mode quadrature oscillator using current differencing transconductance amplifier

This letter proposes a new realization of voltage/current-mode (CM) quadrature oscillator (QO) using Current Differencing Transconductance Amplifier (CDTA) as the active element. The proposed circuit employs canonic number of components, namely two CDTAs, one resistor and two grounded capacitors. The oscillator is capable of providing two explicit quadrature current outputs and two quadrature voltage outputs. Moreover, the circuit enjoys the advantage of independent control of condition of oscillation (CO) and frequency of oscillation (FO). The non-ideal analysis and sensitivity study of the circuit has been carried out and the circuit exhibits a good sensitivity performance. B2SPICE simulation results are included that validate the working of the circuit.     

Simple first order all-pass section using a single CCII

A novel first order all-pass section using a single second generation current conveyor is given. In addition the circuit uses two resistors and only one capacitor. The circuit is also realized with a translinear conveyor. The latter circuit uses only one external resistor and a capacitor. The proposed circuits are verified using PSPICE with attractive results.     

30 GHz SiGe active inductor with voltage controlled Q

An active inductor (AI) based on a cascade gyrator for 30 GHz applications implemented with a 0.25 μm in SiGe technology is presented. The gyrator converts not only a key capacitor into an inductor, but also an added resistor, into a negative resistor. This gyrator-RC has its losses compensated by the negative resistor improving the active inductor Q factor. Changing the bias voltage and current allows to obtain a variable AI. A study of a cascade gyrator AI topology is done to understand the circuit behavior and key elements. For this purpose, an AI impedance model is introduced and discussed. An improved AI with the added resistor replaced by a voltage controlled mosfet resistor is proposed. This extra control voltage allows the variable AI quality factor fine tuning. Schematic and circuit extracted from layout simulations are presented, and compared with the measured results of two prototypes of the AIs (one with a fixed resistor and other with a voltage controlled resistor). A prototype of a high pass filter using the AI with fine Q control was fabricated. Non-linear simulations for different input signal levels were performed and compared with measurements. Also discussion on the non-linear models accuracy is performed.     

Current‐mode quadrature oscillator using current differencing transconductance amplifiers

This article presents a new electronically tunable single‐element‐controlled current‐mode quadrature sinusoidal oscillator circuit using current differencing transconductance amplifiers (CDTAs). The proposed oscillator is consisted of two CDTAs, two grounded capacitors and one grounded resistor, which is beneficial to monolithic integrated circuit implementation both in CMOS and bipolar technologies. The condition of oscillation and the frequency of oscillation are independently controllable. The frequency of oscillation can also be electronically controlled by adjusting the bias current of CDTA. The circuit provides four quadrature current outputs and two quadrature voltage outputs. The current output terminals possess high impedance level. PSPICE simulation results are used to verify the performance of the proposed circuit implemented at the transistor level. The measurement results support the computer simulations.     

不受温度影响的电流源

为了改进电流源电路的温度特性,提出了一种对温度不敏感的高精度电流源的实现方案。与现有的电路相比．本电路并没有改变原来的主电路结构．而仅仅在参考电流源中增加了一个小电阻。它在零下50℃到150℃的大范围内的温度效应被限制在1％-2％。该电阻在芯片上是利用闲置区域布线的,因此并不会增加集成电路的制造成本。另外．该电阻是连接在恒流源中,不会增加芯片的功耗。     

Nth order current mode universal filter using MOCCCIIs

This article presents a new current mode single-input-multiple-output nth order universal filter. The proposed circuit employs (n + 1) number multiple output second generation current conveyors and n number grounded capacitors only. Presented circuits can realize current mode low pass, high pass, band pass, notch and all pass responses simultaneously at different high output impedance terminals. The current mode filter circuit provides low input impedance by selecting the proper value of bias current and also has high output impedance, which is suitable for cascading. The circuit offers some important features such as resistor less realization, no passive component matching constraints, low sensitivity, electronic tunability and active-C realization. The functionality of the proposed filter circuit is tested with the PSPICE simulation, which is found to agree well with the proposed theory.     

基于CDCTA的双模式等幅正交振荡器

针对正交振荡器实现复杂、振幅不相等、模式单一等问题,提出了一种基于电流差分级联跨导放大器的双模式正交振荡器。该电路仅使用一个电流差分级联跨导放大器、一个接地电阻和两个接地电容,可以同时产生等幅电压和电流正交信号。电路结构简单,灵敏度低,易于集成,振荡条件和振荡频率可相互独立地电控调谐。PSPICE仿真与硬件实验结果验证了理论分析的正确性。     

Low-power analogue computational blocks based on high-performance floating-gate MOSFET resistor

This article proposes a new FGMOS-based programmable FGMOS resistor. A highly linear resistor is implemented by cancelling the non-term present in the drain current equation of MOSFET operating in the linear region. The inherited features of FGMOS resistor are simplicity, programmability, wider bandwidth and very low power dissipation without supply voltage. The power dissipation of the proposed FGMOS resistor is only 985 nW. Analogue computational blocks such as programmable reciprocal circuit, current to voltage converter and low-pass filter as applications of proposed programmable FGMOS resistor are also suggested. The power dissipation of reciprocal circuit and low-pass filter are 14.7 and 131 µW, respectively. To demonstrate the efficacy of the circuits, simulations are carried out using SPICE on 0.13 µm CMOS technology.     

Single CDTA-based current-mode quadrature oscillator

This letter presents a single CDTA (Current Differencing Transconductance Amplifier)-based current-mode quadrature oscillator (QO). The proposed circuit structure is very simple, which only consists of one CDTA, one resistor and two capacitors, and it is easy for monolithic integration. The oscillation frequency of the QO can be electronically controlled by the bias current of the CDTA. Moreover, the oscillator can provide two quadrature current outputs. PSPICE simulation results are provided to verify all the theoretical analysis.     

一种高稳定、低温漂的LD驱动电路设计

论文介绍半导体激光器（LD）驱动电路的工作原理及几种驱动电路的特点,着重介绍恒流方式的驱动电路。通过对影响驱动电流稳定性和温度漂移的因素分析,提出合理设计方案。方案中驱动电路的采样电阻由金属导线与负温度系数电阻串联组成,从而减小因采样电阻值随温度变化而引起驱动电流的漂移。     

Simple square-rooting circuit using OTAs

A method to implement a square-rooting circuit is described. The proposed circuit employs operational transconductance amplifiers (OTAs) as the only active elements. The implementation technique is based on an electronically variable resistor formed by the OTA, where the magnitude of the resistance is controlled by the output current, to provide the square-rooting function. The proposed scheme can operate with both a voltage input and a current input signal. The purpose of the circuit is emphasised in terms of simple configuration, high accuracy and low cost. Experimental results showing the circuit performance are presented.     

静电放电模拟器电路建模分析

从实际的静电放电模拟器结构出发,根据接触放电时静电放电电流的主要特征,考虑到静电模拟器本身、连接线及回路电缆与地平面间产生的分布参数的影响,建立了一个新的静电放电模拟器等效电路模型,并用PSPICE软件对等效电路进行模拟分析,得到了与实测波形基本一致的电流波形.利用该模型讨论了各分布参数对放电电流的影响.结果表明:模拟器体电阻与地间的电感对电流波形影响不大,因此可以忽略,但其与地之间的分布电容对电流波形的低频段有重要影响;连接线分布参数对电流波形的第一峰值及波形光滑度都有影响;回路电缆分布参数主要影响了电流波形中第二个波峰峰值及其位置.     

准平面型InAlAs/InGaAs异质结双极晶体管和单片集成激光器驱动电路

提出和制作了准平面型InAlAs/InGaAs异质结双极晶体管。该管主要采用硅离子注入法在半绝缘磷化铟衬底中形成隐埋型集电区以代替台面型集电区。晶体管的实测结果如下:h_(fe)=100,f_T=10GHz(V_(CE)=3V,I_c=10mA)。作为单片光电集成方面的实例,研制成功了由三个InGaAs/InAlAsHBT和一个电阻组成的激光器驱动电路,其电流调制速率高达4Gbit/s。     

Self generating square/triangular wave and pulse width modulator using a single MO-CCCDTA

A self-generating square/triangular wave and pulse width modulator (PWM) using multiple output current controlled current differencing transconductance amplifier (MO-CCCDTA) is presented. To obtain all the three functions simultaneously from the same topology, the MO-CCCDTA is modified a little bit. The characterisation of the modified MO-CCCDTA structure shows that the parasitic resistances at input terminals (n and p) can be varied via bias current. The maximum useful frequency range is found to be 635 MHz, which is higher than the available literature. The waveform generator and PWM circuit use only one MO-CCCDTA, one grounded capacitor and no resistor; hence suitable for IC implementation. The duty cycle of proposed pulse width modulation can be tuned by bias current of MO-CCCDTA over a wide range. The performances of the proposed block and its applications (square/triangular/PWM) are verified by PSPICE simulation using TSMC 0.35 µm technology. The power consumption is about 1.12 mW. To verify experimentally, a prototype of MO-CCCDTA has been made using commercially available ICs (AD844AN and CA3080) on printed circuit board. The simulation and experimental results verify theoretical proposition well. Monte carlo simulation is carried out, which proves satisfactory performance of the proposed circuit against mismatches. The performance of the proposed circuit is also verified through pre-layout and post-layout simulation results. The required chip area is only 22.415 × 14.6 µm².