两级式电流馈电推挽变换器的设计

与传统的两级式电压馈电推挽变换器相比,两级式电流馈电推挽变换器省去了前级降压式变换电路（BUCK）的输出电容和后级推挽的输出电感,因而在低压大电流多路输出的应用场合具有较大优势。文章介绍了该变换器的工作原理和主要参数设计,并进行了实验验证。实验表明：该变换器具有输入电压范围宽、开关管电压应力小的优点。     

全集成片上低温漂振荡电路

设计了一个全集成低温漂振荡电路,该电路通过将片上环形振荡器产生的振荡信号的频率转换为电压,并与片上基准电压源产生的基准电压进行比较,产生振荡器控制电压,实现稳定振荡器工作频率的目的.由于片上基准电压源和频率-电压转换电路具有较小的温度系数,振荡器的工作频率也具有较小的温度系数(140 ppm/℃).该电路无需从片外接收任何基准信号.另外,该设计具有对振荡器工作频率的负反馈调整机制,与单独的振荡器相比,输出信号的频率更加稳定,在0～100 ℃范围内,输出信号频率的变化小于1.35%.     

基于Buck变换器的双环开关调节系统的设计和仿真

Buck电路是一种降压斩波器,降压变换器输出电压平均值Vo等于占空比乘以输入电压Vin。通常电感中的电流是否连续,取决于负载的大小,所以简单的BUCK电路输出的电压不稳定,一旦负载突变会造成严重后果。加入闭环控制系统,输出电压经采样环节后和参考电压比较,同时在此基础上引入电流反馈,得到的误差信号送至控制器,控制器输出信号送至PWM环节和锯齿波时钟信号比较,改变占空比d即可调节开关变换器的输出电压,达到稳定电压的目的。     

交错并联BUCK变换器的仿真研究

目前双向DC/DC变换器是电力储能系统的重要组成部分,而其中BUCK电路是其最基本的拓扑之一,交错并联技术指的是并联运行的各通道的控制信号频率相同,并且相位互相错开的运行模式。因此文章分析了交错并联BUCK变换器的工作过程,并且通过PSIM仿真对每相交错并联BUCK变换器进行了验证,结果表明,交错并联技术能减小输出电流纹波,并且有相数越多,越能降低纹波的效果,提高了变换器的效率。     

峰值电流模式升压DC-DC变换器中斜坡补偿的分析与设计

本文通过分析固定频率、峰值电流模式升压DC-DC变换器中斜坡补偿的基本原理,提出了一种简单实用的斜坡补偿电路。该电路利用恒定电流充放电型振荡器产生的斜坡电压信号,通过一个V-I电路转换成可作为斜率补偿用的斜坡电流信号。     

一种快速响应数字COT控制Buck变换器

提出了一种数字恒定导通时间(COT)控制的DC-DC Buck变换器。通过跨导放大器、流控振荡器(CCO)和数字滤波器对电感电流进行采样,形成电流内环。在基于ADC、PI补偿器的电压外环输出信号上叠加由误差电流、CCO产生的斜坡补偿信号,最终形成双环控制的Buck变换器电路。提出的数字谷值电流模COT控制方法采用数字电流内环和额外的斜坡补偿方式,加快了电路的瞬态响应,同时保持了数字电源高输出精度的特性。该Buck变换器在输入电压5 V、输出电压3.3 V、开关频率1 MHz下进行了仿真验证。仿真结果表明,负载上阶跃和下阶跃响应时间分别为11 μs和17 μs。     

用于峰值电流模Boost变换器的瞬态响应优化电路

为了提高瞬态响应速度,提出了一种用于峰值电流模PWM控制Boost变换器的瞬态响应优化电路。传统峰值电流模Boost变换器的带宽因受限于右半平面零点而限制了负载阶跃时的瞬态响应速度。该优化电路根据输出电压信号来输出自适应瞬态增强电流信号,优化了变换器的瞬态响应特性。采用0.18 μm BCD工艺对电路进行仿真验证。结果表明,负载电流从1 A变化到200 mA时,负载阶跃恢复时间从65 μs减小到50 μs;负载电流从200 mA变化到1 A时,负载阶跃恢复时间从46 μs减小到33 μs。     

由六反相器构成的DC/DC变换器

上图所示的电路用一个ＴＴＬ六反相器即可构成 ＤＣ／ＤＣ变换器,将５Ｖ变成１２Ｖ。该电路提供了ＤＣ／ＤＣ变换所需的所有功能。 该电路依靠 ＴＴＬ开关门限调节电压。 Ｕ１Ａ和Ｕ１Ｂ形成振荡器,其开关频率＜１ＭＨｚ。振荡器的输出驱动三个并联的反相器 Ｕ１Ｃ、 Ｕ１Ｄ和 Ｕ１Ｅ,可提供较高的输出电流和输出功率。其内部输出晶体管、Ｌ１和 Ｄ１形成标准的升压转换器,当其输出为低时,电流只流过电感Ｌ１;当其输出变高时,储存在电感中的能量迫使Ｄ１的阳极变高,Ｄ１导通对Ｃ１充电。 Ｕ１Ｆ监视输出电压在反馈电阻 Ｒ１和 Ｒ２…     

一种用于DC-DC转换器的精密振荡器设计

提出了一种用于DC-DC转换器的高频、精密张驰振荡器的设计方法.基于V-i转换器原理,设计了精密电流产生电路;基于基极电流补偿技术,设计了一种结构新颖的比较器门限电压产生电路,从而有效地提高了振荡器频率稳定性和精度.通过外接可调电阻,振荡器可调工作频率为100 kHz～3 MHz,并能同时提供占空比85%的方波信号和用于斜率补偿的锯齿波信号,还具有与外接时钟信号同步振荡的功能.流片测试结果表明该振荡器满足设计指标.     

一种新的2.45GHz频率综合器设计与实现

提出了一种新的基于数字FLL的高速、低功耗2.45GHz频率综合器结构,它由鉴频器、数字控制电路、电流控制振荡器组成.它采用高速鉴频器对振荡器输出信号计数实现鉴频,数字控制电路根据鉴频结果调节振荡器输出信号频率来实现输出信号频率与目标频率的锁定.高速分频器基于异步计数结构,降低了内部模块工作频率,使得系统性能稳定;数字控制电路采用逐次逼近算法,使得锁定速度快;基于差分电流饥饿延迟单元的电流控制振荡器采用电流-电容双控模式,使得输出频率调节范围宽、精度高.该电路结构简单,易于实现,版图面积为13 200μm2.在0.18μm工艺下,仿真结果显示,其锁定时间为14μs;输出频率调节范围为1~4.5GHz;输出频率锁定2.450GHz;功耗为4.622mW.     

Minimum component SRCO and VFO using a single DVCCC

Two oscillator topologies each employing a single differential voltage complementary current conveyor (DVCCC) are presented. The first oscillator uses a single active element, five passive components, grounded capacitors, has independent control of frequency and condition of oscillation. It has a current mode output and can be extended to provide a voltage mode output. It combines all the features of the current state-of-art oscillators. The second oscillator uses a single DVCCC, four passive elements, grounded capacitors and provides independent control of frequency. This oscillator not only has all the desired oscillator features, but requires lesser passive components. Theoretical analysis of these oscillators was verified with SPICE simulations.     

Current conveyor-based voltage-mode two-phase and four-phase quadrature oscillators

A voltage mode two-phase quadrature oscillator using plus-type second generation current conveyors [CCIIs(+)] is realized by using a simple technique. The basic building block for this technique is a voltage mode non-inverting band-pass filter. The two-phase quadrature oscillator is then transformed into a four-phase quadrature oscillator by replacing the two CCIIs(+) by two dual output, current conveyors [DO-CCIIs]. The proposed circuits enjoy attractive features such as use of grounded passive components, independent frequency control, outputs of almost equal magnitude and low sensitivity figures. Both the oscillator circuits are designed and verified using PSPICE simulation.     

High frequency current mode oscillator employing fTintegration technique

A low distortion high frequency oscillator is described, which is a development of the recently proposed f_T-integrator, in which an amplitude control circuit is embedded inside the integrator. Simulation results suggest that, for the oscillation range 1-2.6 GHz, the total harmonic distortion (THD) of the output current signal is well below 0.5% for the output current level at 50% modulation depth (peak-to-peak). The phase noise of the oscillator is simulated to be -72 dBc/Hz at 1 MHz offset for 1% THD output current     

Phase-Noise Reduction of X-Band Push–Push Oscillator With Second-Harmonic Self-Injection Techniques

A low phase-noise X-band push-push oscillator using proposed feedback topology is presented in this paper. The oscillator core was implemented in a 0.18-mum CMOS process. By using a power splitter and a delay path in the feedback loop connecting the output and current source of the oscillator, a part of the oscillator output power injects to the oscillator itself. With the proper phase delay in the feedback loop and high transconductance of the current source, a low phase-noise oscillator is achieved. The amplitude stability and phase stability are analyzed, the phenomena of the phase-noise reductions are derived, and the device-size selections of the oscillator are investigated. The time-variant function, impulse sensitivity function, is also adopted to analyze the phase-noise reductions of the second-harmonic self-injected push-push oscillator. These theories are verified by the experiments. This self-injected push-push oscillator achieves low phase noise of -120.1 dBc/Hz at 1-MHz offset from the 9.6-GHz carrier. The power consumption is 13.8 mW from a 1.0-V supply voltage. The figure-of-merit of the oscillator is -188.3 dBc/Hz. It is also the first attempt to analyze the second-harmonic self-injected push-push oscillator     

Electronically tunable multiphase sinusoidal oscillator using translinear current conveyors

A new electronically tunable current-mode multiphase sinusoidal oscillator based on translinear current conveyors is presented. The proposed oscillator circuit, which employs only one translinear current conveyor and one grounded capacitor for each phase, can generate arbitrary N output current equal-amplitude signals that are equally spaced in phase (N being even or odd), all at high output impedance terminals. The frequency of oscillation and the condition of oscillation can be controlled electronically and independently through the bias current of the translinear current conveyor. The proposed structure also has simple circuitry, low-component count, and is highly suitable for integrated circuit implementation. The theoretical results were verified by PSPICE simulation. In addition, the modification of the N sinusoidal oscillators to construct a programmable multiphase oscillator is also discussed.     

Current-mode variable frequency quadrature sinusoidal oscillators using two CCs and four passive components including grounded capacitors

This paper reports realizations of current-mode quadrature sinusoidal oscillator using only two multiple-output current conveyors (first or second generation current conveyor CCI/CCII) and four passive components including two grounded capacitors. Therefore, the circuits employ minimum number of passive components to realize a second-order sinusoidal oscillator. Three types of circuits are reported depending on the condition of oscillation and frequency of oscillation (FO). The circuits have FO controllable by either resistor or capacitor and are suitable to be used as variable frequency oscillator for different applications. All the circuits provide two explicit quadrature current outputs from high output impedance terminals. PSPICE simulation results are included to verify the workability of the proposed circuits.     

A new single MCCCDTA based Wien-bridge oscillator with AGC

This paper presents a new current-mode Wien-bridge oscillator with automatic amplitude control. The oscillator only employs single MCCCDTA as the active element and provides two current outputs with small distortion from high output impedances. Its oscillation condition and frequency can be tuned electronically, linearly and independently through tuning bias currents of MCCCDTA. The circuit simulation results are in agreement with theory.     

94GHz连续波40kW回旋振荡管高频系统的设计

W波段的高功率连续波回旋管振荡器在毫米波非致命武器等领域有着重要的应用。该文首先通过起振电流的计算,确定了工作模式,继而利用自行开发的自洽非线性计算程序GYROSC对工作在94GHz频率的连续波回旋振荡管高频系统进行了模拟计算和优化设计。结果表明,设计的W波段连续波回旋管可获得输出功率40kW,电子效率大于30%。     

Current-Mode Multiphase Sinusoidal Oscillator Using Current Differencing Transconductance Amplifiers

This paper describes a simple current-controlled current-mode multiphase sinusoidal oscillator based on current differencing transconductance amplifiers (CDTAs) as active components. The proposed oscillator circuit, which employs only one CDTA and one grounded capacitor for each phase, can generate arbitrary n current-output signals (n being even or odd) equally spaced in phase, all at high output impedance terminals. The oscillation condition and the oscillation frequency can be controlled electronically and independently through the bias current of the CDTA. The oscillator has low-component count, low-sensitivity performance, and is highly suitable for monolithic implementation. PSPICE simulation results are given to confirm the operation of the proposed oscillator.     

一种CMOS电流控制振荡器的分析与设计

提出了一种结构简单的CMOS电流控制模式振荡器.该电路充分利用系统内部基准电流源产生的电流信号对电容进行充放电,在5 V电源电压下,经过控制电路作用后,上升时间和下降时间非常小,使产生的输出振荡波形更接近理想矩形波;通过调节基准源电流信号或者电路中电容值的大小,可以调节振荡输出波形的频率和占空比.