BBD的原理及其在延时混响中的应用

本文着重介绍了 BBD 器件的原理性能以及 BBD 器件在延时混响装置中的应用。此外还介绍了新设计实验的 BBD 器件延时混响器样机的原理图和性能。     

BBD音响效果电路

现代音响系统的特点,不仅在于获得高保真度,而且还在于根据心理声学原理,利用电子技术对音频信号处理,使放送的音乐更为优美动听,并且在需要时产生某种特殊音响效果。CCD和BBD的出现,为达到上述要求创造了新的条件,尤其是BBD器件价格较低、电路简单、效果显著,所以国外在录音机和其他音响系统中越来越多地应用BBD器件。     

大屏幕彩电新电路新技术精萃(17) BBD延迟电路与混响电路

BBD延迟电路 BBD是Bucket Brigade Device的缩写。常作为斗链式模拟延迟器件的简称。它是一种电荷耦合器件，即输入信号在时钟脉冲作用下以电荷形式一级一级地耦合传递。大屏幕彩电卡拉OK系统的延迟电路通常采用MN3208（长虹彩电NQK06)与时钟信号发生器MN3102(NQK07)配对使用，如图30所示。     

简易混响和环绕声发生器

即使数码混响和延时IC在我国已大量采用,但数年前松下的BBD器件在“民间”亦有不少,让其发挥“余热”更是部分读者的要求。     

CCD摄象器件(1)—CCD摄象器件的基本概念

电荷耦合器件(CCD)是1970年在MOS工艺基础上发展起来的新型半导体器件。它和戽链器件(BBD)等一起,通常统称为电荷转移器件(CTD)。与以前在热平衡状态下工作的双极和单极半导体器件相反,CCD是一种在非平衡状态下依靠势阱转移电荷信息的、具有独特工作机构的器件;是在硅工艺     

BBD结构红外焦平面CMOS_TDI读出电路

BBD(戽链器件)因能与标准CMOS工艺兼容而受到了人们的重视.许多人开始研究基于BBD结构的红外焦平面读出电路,即以BBD结构实现时间延迟和积分功能(CMOS_TDI).基于CMOS的读出电路驱动时钟简单,采用标准逻辑电源电压工作,与外界电路之间的接口方便;并且工作电压较低,使读出电路可以实现微功耗;可以将信号读取和处理电路、驱动与控制电路甚至A/D转换器、数字信号处理电路以及全数字接口电路等完全集成在一起,实现所谓的"智能型"红外焦平面;另外,由于采用标准的CMOS工艺,因而又具有低成本的特点.     

电荷转移器件的地位及其发展方向

电荷转移器件是利用电荷群沿半导体表面移动而传输信息的器件。自1969年San-gster发表BBD和1970年Boyle及Smith发表CCD以后。此种器件迅速地发展起来。它与先后发表的磁泡器件和等离子体耦合器件一样,是具有移位寄存器功能的功能器件。不过,它与以往的二极管、晶体管等具有多种功能的电子器件有着根本的不同。组成移位寄存器的各芯片间必须用金属丝互连,但作为功能器件的电荷转移器件却可以直接连结。因此,可以提高集成度。该特点是功能器件本身所固有的。不过该功能的作用范围还不很广,这是其不足。但是,电荷转移器件有可能应用于自扫描摄象器、存储器、延迟器件等场合。     

AV功放原理与维修讲座(3)——第三讲 卡拉OK电路

<正> 早期的卡拉OK电路较为简单,主要由话筒放大电路和音乐信号混合电路组成。以后又增加了以BBD延时器件为核心的混响电路。90年代中期,随着音频数字信号处理技术的迅速发展,卡拉OK领域内的音频处理技术也得到了长足的进步,新一代的数码延时芯片的信噪比、失真度、频响和动态范围的指标均在BBD延时芯片之上,因此很快便在各类音响器材中得到了广泛的应用。如今,卡拉OK已成为AV功放等音响器材的必备功能。 图1是目前AV功放中常见的卡拉OK核心电路的原理     

CCD摄象器件(9)——迭层状单片式彩色摄象机

在单片式彩色摄象机中,我国已经有过将摄象器件的光敏区和转移区作成立体状两层结构方式的两篇报导。本文是采用ZnSe—Zn_(1-x)Cd_xTe:In膜的高灵敏度迭层结构,摄象器件的转移区由BBD和CCD组合而成,用嵌镶状滤色器构成单片式彩色摄象机。这种方法,由于摄象器件采用了迭层结构,因而提高了光敏面积的效率,而且改善了电晕控制。摄象器件摄象器件的转移区通常采用图1所示的内线方式,这种方式是用光电二极管作成的光敏区将入射光转变为信号电荷,仅对这些信号电荷进行一帧时间的积分,在熄灭时间内输入垂直转移线,每隔一水平扫描时间转     

黄山AH2588C/R彩电卡拉OK电路原理与检修

<正> 黄山AH2588C/R彩电卡拉OK电路原理框图如图1所示。该电路由话筒前置放大电路、延迟混响电路、有源低通滤波器和混合信号放大电路等组成,其核心器件是BBD延迟集成块NK01(BL-3207),具体电路原理图如图2所示。     

A numerical analysis of bulk-barrier diodes

A selfconsistent numerical analysis of bulk-barrier diodes (BBD) is presented. The principal way of operation of a BBD is explained. A computer program which can accurately model second order effects is used to achieve basic understanding of the internal electric behaviour of a BBD. The distributions of the relevant physical quantities in the interior of a BBD are discussed. Measured and simulated characteristics which show good agreement, owing to the carefully modeled physical parameters, are compared. The sensitivity of electrical properties to minute variations of the doping profile is presented. This can only be done by a program simulating the characteristics of a BBD. The advantages and disadvantages of a BBD compared to a standard silicon diode and a Schottky diode are discussed.     

Fast optimal and suboptimal any-time algorithms for CDMA multiuser detection based on branch and bound

A fast optimal algorithm based on the branch-and-bound (BBD) method is proposed for the joint detection of binary symbols of K users in a synchronous code-division multiple-access channel with Gaussian noise. Relationships between the proposed algorithms (depth-first BBD and fast BBD) and both the decorrelating decision-feedback (DF) detector and sphere-decoding algorithm are clearly drawn. It turns out that decorrelating DF detector corresponds to a "one-pass" depth-first BBD; sphere decoding is, in fact, a type of depth-first BBD, but one that can be improved considerably via tight upper bounds and user ordering, as in the fast BBD. A fast "any-time" suboptimal algorithm is also available by simply picking the "current-best" solution in the BBD method. Theoretical results are given on the computational complexity and the performance of the "current-best" suboptimal solution.     

Modeling and experimental simulation of the low-frequency transfer inefficiency in bucket-brigade devices

The work presented in this paper extends the available theory and it also presents a model for the low-frequency charge transfer in MOS bucket-brigade devices (BBD's). Our new theory which characterizes the low-frequency component of transfer inefficiency in terms of the subthreshold current is frequency independent and it incorporates both channel-length and barrier-height modulations. This model was verified experimentally on simulated BBD's. After proving both theoretically and experimentally that the low-frequency transfer inefficiency of BBD devices is due to subthreshold current, we successfully used this knowledge to design an improved BBD device. This improved device includes only one extra ion-implantation step relative to the original BBD device. An ion implant is used in part of the BBD channel.     

Tunable Matched Filters for Pulse-Code Modulation Using Charge-Transfer Devices

A tunable matched filter for the major PCM codes has been synthesized utilizing a developmental bucket-brigade delay (BBD) line. The variable delay feature of the BBD allows continuous tuning of the matched filter over a wide range of bit rates. By combining and weighting the outputs of two BBD lines, matched filters for nonreturn-to-zero (NRZ), return-to-zero (RZ), and biphase codes are realized with a signal-to-noise performance within 0.8 dB of theoretical.     

An optimized bidirectional lightning surge protection semiconductordevice

This paper addresses the analysis of a bidirectional lightning surge protection power semiconductor device called the bidirectional breakover diode (BBD). The BBD has a high-speed response, high current capability, and low conduction and switching losses. The influence of the layout on the trigger and holding current values has been studied by means of two-dimensional (2-D) electrical simulations. The length of the peripheral N⁺ diffusion together with the location of the edge contact between the metallization and the P⁺/N⁺ diffusions are crucial in optimizing the trigger mechanism and the trigger and holding current values. The turn on of the inner cells has also been analyzed by numerical simulations, showing the effect of the central parasitic P⁺NP⁺ bipolar transistor at the initial phase of the turn on process. Experimental results have been obtained from fabricated 180-V BBD devices with holding current values in the range of 150-250 mA. The BBD surge protection capability has been corroborated by impulsive tests using a 10/1000 μs, 50 A, 1000 V, current pulse. In addition, transient losses have been monitored in order to improve the surge protection capability of the device. Finally, the static and dynamic BBD thermal behaviour has also been analyzed     

Transversal filtering using charge-transfer devices

Techniques are presented for making transversal filters using charge-coupled devices and bucket-brigade devices. In a CCD transversal filter, the delayed signals are sampled by measuring the current flowing the clock lines during transfer, and the sampled signals are weighted by a split electrode technique. In a BBD transversal filter, the delayed signals are `tapped' with a source follower whose load determines the weighting coefficient. Examples are given of CCD and BBD filters that are `matched' to particular signalling waveforms, and the limitations of charge-transfer devices in matched filtering applications are discussed. Finally, the application of CTD transversal filters to other signal processing functions is discussed.     

Measurement selection for parametric IC fault diagnosis

This article presents experimental results which show feedforward neural networks are well-suited for analog IC fault diagnosis. Boundary band data (BBD) measurement selection is used to reduce the computational overhead of the FFN training phase. We compare the diagnostic accuracy between traditional statistical classifiers and feedforward neural networks trained with various measurement selection criteria. The feedforward networks consistently perform as well as or better than the other classifiers in term of accuracy. Training using BBD consistently reduces the FFN training efforts without degrading the performance. Experimental results suggest that feedforward networks provide a cost efficient method for IC fault diagnosis in a large scale production testing environment.This work is supported by NSF-IUC CDADIC, Project 90-1.     

Dual-gate bucket-brigade devices

The low charge-transfer efficiency of the basic bucket-brigade circuit and the speed limitation of the tetrode approach have so far prevented bucket-brigade devices (BBD's), in spite of their greater fabrication simplicity, from competing with charge-coupled devices, excepting for audio applications. A novel charge-transfer device is presented and experimentally evaluated. The "dual-gate BBD" is a two-step-transfer device (a CCD transfer followed by a BBD transfer), showing operational performances comparable to surface-channel CCD's and, at the same time, enjoying the fabrication simplicity proper to bucket-brigade circuits. The concept is implemented using conventional p-channel aluminum-gate technology combined with an additional shadowed-gap float-off process. The characteristic features and the performance capabilities of the device are discussed.     

A V-groove oxide isolated bipolar bucket brigade shift register

A V-groove oxide isolated bipolar bucket brigade shift register structure is described in this paper. The operation of the shift register is analyzed to determine the frequency and transfer efficiency limitation and point out the inherent advantages of such a structure. Measurements carried out on experimental 36-stage V-groove BBD registers are presented to demonstrate the capabilities of the devices. The proposed V-groove BBD structure results in registers with higher operating frequencies and greatly increased packing density when compared to standard junction isolated devices. These improvements are obtained without sacrificing the low or mid-frequency response and make these devices useful in video delay line applications.     

CW laser oscillation at 5433 Å in neon

Laser action in BBD and isopropyl-PBD pumped by the N2laser has been observed. The energy outputs, optimum concentrations, and wavelength ranges for several ultraviolet-lasing dyes were also determined.