双积分A/D转换器的量程自动转换

介绍了一种双积分式A/D转换器在宽范围量程测量中的自动量程转换技术.在测量仪表的输入通道中,用计数器对双积分型A/D转换器本身所固有的过量程/欠量程信号计数,计数器的输出作为量程编码去控制量程的选择,同时又是送到CPU的量程指示信号.该技术扩大了A/D转换量程,提高了精度,设计简单,工作可靠.     

弹载开环光纤陀螺V/F变换器设计

为解决弹载开环光纤陀螺(O-FOG)信号数字化问题,介绍一种高精度低成本的电压/频率(V/F)变换器,它能在全温度范围内工作而无需温控,对其技术要求、实现方法、工作原理和提高精度的措施等进行了讨论.该电路采用仪表放大器AD620作为前置放大级,实现V/I变换,后端采用全电流积分、电荷平衡变换方式,实现L/F变换,它可对输入信号进行连续积分,不会丢失姿态信息.由于弹上能源紧张,利用通用电源±15V(模拟集成电路用),产生双向恒流源复位,避免了单恒流源需要隔离电源(三通道电路需增加3个隔离的+12V)的麻烦.经过对原理样机进行高低温性能测试,得到了满意的结果.     

New wide-range fast-response analogue measurement of frequency

A new high-performance analogue-type frequency/voltage (F/V) convertor is suggested. The proposed convertor shows good linearity and low ripple in a wide range from low to medium frequency. It has great simplicity and good dynamic response as fast as a high-performance digital F/V convertor.     

Dual translinear voltage/current convertor

A new voltage/current convertor (VCCS) using a translinear loop and two current mirrors is described. This convertor has two bipolar outputs, and two different loads can be used. The properties of this convertor are presented for direct current and sinusoidal input signals.     

关于本质安全Boost变换器的探讨

分析Boost变换器工作于连续导电模式（CCM）和不连续导电模式（DCM）时的电感电流,指出当输入电压为最低。负载电阻为最小时,且变换器工作在CCM下的最大电感电流就是该变换器在整个工作范围的最大电感电流。并将其与最小点燃电流相比较作为变换器内部本质安全的判断依据。实验结果验证了理论分析的正确性。     

Algorithmic analogue-to-quaternary convertor circuit using current-mode CMOS

A new current-mode CMOS algorithmic analogue-to-quaternary data convertor circuit has been realised in a standard polysilicon-gate CMOS technology. This circuit accepts an analogue current input and develops a set of quaternary, base-four, output currents. A single type of convertor cell may be cascaded to the desired number of quaternary output digits. The reference current that defines the full scale input range may be set externally. This circuit is input-output compatible with other previously described VLSI-compatible current-mode CMOS quaternary threshold logic and memory circuits.<>     

Wideband translinear current convertor

A bipolar current-to-current convertor (CCCS) using a PNP-NPN translinear loop and two current mirrors is described. This convertor has a virtual earth input, and may be used to realise voltage-current conversion (VCCS). This convertor configuration enables us to obtain a wideband frequency response. The characteristics of a practical current source are presented.     

Fast digital frequency synthesiser

A new phase-locked-loop type frequency synthesiser is described and tested which employs a digital-analogue convertor to give very rapid coarse frequency switching and optimum lock in speed anywhere in a wide frequency range. The experimental results are in good agreement with theory.     

Precision differential voltage?current convertor

A new differential voltage?current convertor is proposed, which achieves high linearity and is substantially temperature independent. The effects of transistor mismatches and of limited current gain are analysed. Experimental results are given which show a considerable improvement over previous circuits.     

Inductor realisation with a negative-impedance convertor

A circuit consisting of a negative-impedance convertor, suitable for the realisation of an inductor, is presented. For a certain circuit condition the realisation is independent of frequency, and by the variation of a single capacitor the inductance value of the inductor can be varied over a wide range while the resistive part remains constant. Both the inductance and the associated resistive part are shown to be frequency-dependent if this condition is not exactly satisfied.     

0.1A～8A高稳定性恒流器件研究

提高温度稳定性和展宽恒定电流范围是当前恒流器件应用中的两个突出问题。现有根据长沟道场效应原理制备的两端恒流器件,由于工作机理限制已难指望在上述问题上取得有效的进展。本文介绍一种恒流源电路的模块设计思路,新近研制了在很宽电流范围内连续可调的新恒流器件。测试结果表明,该器件样管的输出电流可达0.1A～8A,电流温度系数低达10-4/℃10-5/℃。起始电压低于0.4 V,是一种输出电流范围又宽、稳定性又高的高性能器件。     

Floating-impedance convertors using current conveyors

A floating-negative-impedance convertor and a generalised impedance convertor are described. The circuits use a practical realisation of the CCII+ type current conveyor, the design being based on a differential input/output transadmittance cell.     

Design of a 1.1 GSps 12 bit digital to analog convertor with 56 dBc SFDR at Nyquist frequency

High speed digital to analog convertor (DAC) is a key component in software defined radio systems, digital radars and wide band arbitrary waveform generators. In those applications, the performance of the DAC, especially the wideband dynamic range, is important in determining the system performance. In this paper we present a high speed 12 bit current steering DAC with optimized wideband performance. Theoretical analysis and optimizing strategy are present in this paper along with circuit details and measurement results. Experimental results reveal the proposed circuit is capable to operate up to 1.1 GSps. The measured spurious free dynamic range (SFDR) at low frequency is above 70 dBc at 1.1 GHz of sample rate. The SFDR is better than 56 dBc from DC to Nyquist frequency.     

一种车载DC/DC变换器的研制

由于车载DC/DC变换器的特殊应用环境,要求其具有小体积、大功率、高效率、高抗震的特点。文章研究了一种车载DC/DC变换器,该变换器采用全桥移相ZVS PWM控制和倍流整流技术,能较好地满足车载大功率DC/DC变换器的各种性能指标。文中分析了该变换器的工作原理,给出了实验结果和波形。     

数字输出型多功能传感器研究

基于混合集成技术 ,设计并制作了具有RS2 32标准接口输出的压力 温度多功能传感器。该传感器由压力 温度复合敏感单元、R/V转换及前置放大、A/D转换、可编程RS2 32接口单元等构成。此外开发了传感器的数据采集与处理软件 ,通过软件对原传感器的误差进行软补偿 ,传感器的测量综合精度有所提高 ,在室温至 80℃的测量范围内零位温漂由 4 .4 % /℃降至 0 .2 % /℃。     

基于FPGA的高分辨率D／A转换器的实现

为增强FPGA（现场可编程门阵列）对模拟信号的处理能力,扩展FPGA的应用范围,介绍了一种基于FPGA实现高分辨率D／A转换器的技术。利用FPGA内部PLL（锁相环）,提高时钟信号的计数频率,从而提高PWM（脉宽调制）信号的基波频率,通过5阶巴特沃斯低通滤波器,实现14位高分辨率D／A转换器。阐述了PWM实现D／A转换器的理论基础和实际应用注意事项,该方法已用于实际D／A转换器系统,具有精度高、误差小的优点,对于FPGA的实际应用具有一定的指导意义。     

基于ARM半导体激光器的驱动设计及测试

在半导体激光器的使用过程中,驱动电路直接影响着激光器的稳定性。对此文中提出了一种高效、稳定,宽功率输出范围的设计方案,采用采样电阻和恒流电路实现稳定的闭环控制,得到恒定的驱动电流;利用热敏电阻温度特性,温度控制电路结合单片机控制系统,实现温度的闭环控制,从而实现了稳定的温度控制要求;结合恒温,恒流控制以及单片机系统,设计功率闭环控制方案。实验结果表明,不同温度下,功率计测得功率与驱动电流成良好的线性关系,且功率范围宽、电路可靠工作时间长、激光器单色性稳定、系统稳定性好。     

Integrated optical, acoustically tunable wavelength filter

A TM/TE convertor is combined with a TE-pass polariser on a common LiNbO/sub 3/ chip to obtain an integrated optical, acoustically tunable wavelength filter. Its tuning range is 1.45-1.57 mu m wavelength with a filter half-width of 2.8 nm. Due to the combined acoustical/optical strip guide structure used in the mode convertor, a very low acoustic drive power of only 9 mW is required.<>     

Increased swing convertor for low-internal-voltage ULSI circuits

The authors present an increased swing convertor. It features the switching supply of the input stage, which enables a low operating voltage ratio V_int/V_ext(<0.4) to be achieved without consuming DC current. With parallel driving, speed performance is improved     

Low-power SITL IC

The SITL (static induction transistor logic), which operates in the bipolar mode, has the smallest PD (power delay) product in silicon technology because of the use of an extremely pure epitaxial layer. In this paper, as SITL device is which the gate and drain are self-aligned is described, centering on the DC characteristics and operation limit. It is concluded that the drain current of SIT is limited by the thermionic emission mode in a low-current region of about 1 nA over a wide temperature range, and that logic operation is limited by the effective current gain /spl beta//SUB eff/ in the low-power region. Designing SITL suitably for wide temperature and power range, the authors have developed a monolithic watch IC having an oscillation frequency of 2 MHz and a current consumption of 3.5 /spl mu/A, and including bipolar circuitry on the same chip.