Abstract: This document explains how the Cupertino (MAXREFDES5#) subsystem reference design meets the higher resolution, higher voltage,and isolation needs of industrial control and industrial automation applications. Hardware and firmware design files as well as FFTs andhistograms from lab measurements are provided.
While simplicity and high effi ciency (for cool running) areno longer optional features in isolated power supplies, itis traditionally diffi cult to achieve both. Achieving higheffi ciency often requires the use of advanced topologiesand home-brewed secondary synchronous rectifi cationschemes once reserved only for higher power applications.This only adds to the parts count and to the designcomplexity associated with the reference and optocouplercircuits typically used to maintain isolation. Fortunately, abreakthrough IC makes it possible to achieve both high efficiency and simplicity in a synchronous fl yback topology.The LT®3825 simplifi es and improves the performance oflow voltage, high current fl yback supplies by providingprecise synchronous rectifi er timing and eliminating theneed for optocoupler feedback while maintaining excellentregulation and superior loop response.
High voltage buck DC/DC controllers such as the LTC3890(dual output) and LTC3891 (single output) are popular inautomotive applications due to their extremely wide 4V to60V input voltage range, eliminating the need for a snubberand voltage suppression circuitry. These controllersare also well suited for 48V telecom applications whereno galvanic isolation is required.
The ISO7220 and ISO7221 are dual-channel digital isolators. To facilitate PCB layout, the channels are orientedin the same direction in the ISO7220 and in opposite directions in the ISO7221. These devices have a logic inputand output buffer separated by TI’s silicon-dioxide (SiO2) isolation barrier, providing galvanic isolation of up to4000 V. Used in conjunction with isolated power supplies, these devices block high voltage, isolate grounds, andprevent noise currents on a data bus or other circuits from entering the local ground and interfering with ordamaging sensitive circuitry.
The P82B96 offers many different ways in which it can be used as abus interface. In its simplest application it can be used as aninterface between bus systems operating from different supplyvoltages. Opto isolation between two bus systems is possible, andalso the availability of the Tx and Rx signals permits interfacing ofthe P82B96 with other bus systems which separate the forwardoutput path, from the backward input signal path.
通過(guò)比較各種隔離數(shù)字通信的特點(diǎn)和應(yīng)用范圍，指出塑料光纖在隔離數(shù)字通信中的優(yōu)勢(shì)。使用已經(jīng)標(biāo)準(zhǔn)化的TOSLINK接口，有利于節(jié)省硬件開(kāi)發(fā)成本和簡(jiǎn)化設(shè)計(jì)難度。給出了塑料光纖的硬件驅(qū)動(dòng)電路，說(shuō)明設(shè)計(jì)過(guò)程中的注意事項(xiàng)，對(duì)光收發(fā)模塊的電壓特性和頻率特性進(jìn)行全面試驗(yàn)，并給出SPI口使用塑料光纖隔離通信的典型應(yīng)用電路圖。試驗(yàn)結(jié)果表明，該設(shè)計(jì)可為電力現(xiàn)場(chǎng)、電力電子及儀器儀表的設(shè)計(jì)提供參考。
Abstract:
y comparing characteristics and applications area of various isolated digital communications， this article indicates advantages of plastic optical fiber in isolated digital communications. Using the standardized TOSLINK interface， it helps to control costs and difficulty in hardware development and design. Then it gives the hardware driver circuit of plastic optical fiber module， explains the noticed details in design process， gives results on the basis of the optical transceiver module voltage characteristics and frequency characteristics tests. Finally，it gives typical application circuit of the SPI communication port by using plastic optical fiber isolation .The results show that this design can be referenced for the power field， power electronics and instrumentation design.
硬件設(shè)計(jì)指南(PDF格式)，主要包括：Low Voltage Interfaces；Grounding in Mixed Signal Systems；Digital isolation Techniques； Power Supply Noise Reduction and Filtering； Dealing with High Speed Logic
小波神經(jīng)網(wǎng)絡(luò)好文章！A method for fault detection is proposed using a trained neural network as the nominal
model of the system to be monitored. Partial physical knowledge, if available, can be combined
with the nominal model to perform fault isolation.
