This research work aims at eliminating the off-chip RF SAW filters from fre-
quency division duplexed (FDD) receivers. In the first approach, a monolithic passive
RF filter was constructed using on-chip capacitors and bondwire inductors. The bond-
wire characteristics were studied in details and the effect of mutual inductive coupling
between the bondwires on the filter performance was analyzed. Based on that, a bond-
wire configuration was proposed to improve the frequency response of the filter. The
filter was implemented in 0.18 μm CMOS process for WCDMA applications.
文章提出了一種基于AT89S51單片機的智能家居系統(tǒng)的設(shè)計,該系統(tǒng)具有室內(nèi)煤氣以及煙霧的檢測、家庭室內(nèi)防盜等功能。文章詳細(xì)分析了系統(tǒng)的總體設(shè)計,詳盡分析并設(shè)計了煤氣傳感器模塊、煙霧傳感器模塊、人體紅外感應(yīng)傳感器模塊、報警模塊等各硬件部分,并利用PROTUES軟件進(jìn)行了系統(tǒng)仿真。仿真結(jié)果證明:系統(tǒng)具有成本低、效率高、操作方便等優(yōu)點,達(dá)到了預(yù)期設(shè)計的效果。This paper presents the design of an intelligent home system based on AT89S51 microcontroller.The system has the functions of detecting indoor gas and smoke,guarding against theft in the home,and so on.The overall design of the system is analyzed in detail.The gas sensor module,smoke sensor module,human infrared sensor module,alarm module and other hardware parts are analyzed and designed in detail,and the system simulation is carried out using PROTUES software.The simulation results show that the system has the advantages of low cost,high efficiency,convenient operation and so on,and achieves the expected design effect.
設(shè)計功率MOSFET驅(qū)動電路時需重點考慮寄生參數(shù)對電路的影響。米勒電容作為MOSFET器件的一項重要參數(shù),在驅(qū)動電路的設(shè)計時需要重點關(guān)注。重點觀察了MOSFET的開通和關(guān)斷過程中柵極電壓、漏源極電壓和漏源極電流的變化過程,并分析了米勒電容、寄生電感等寄生參數(shù)對漏源極電壓和漏源極電流的影響。分析了柵極電壓在米勒平臺附近產(chǎn)生振蕩的原因,并提出了抑制措施,對功率MOSFET的驅(qū)動設(shè)計具有一定的指導(dǎo)意義。When designing the drive circuit of power MOSFET,the influence of parasitic parameters on the circuit should be concerned.As an important parameter of MOSFET device,Miller capacitance should be considered in the design of drive circuit.The variation of gate voltage,drain source voltage and drain source current during the turn-on and turn-off of MOSFET were observed.The influences of parasitic parameters such as Miller capacitance and parasitic inductance on drain source voltage and drain source current were analyzed.The reasons of gate voltage oscillation nearby Miller plateau were analyzed,and the restraining measures were put forward.This research was instructive for the drive design of power MOSFET.
以單片機控制A/D轉(zhuǎn)換器TLC549為例,對A/D轉(zhuǎn)換器的主要技術(shù)指標(biāo)進(jìn)行了分析研究,在Proteus平臺下,完成了A/D轉(zhuǎn)換電路的構(gòu)建,采用器件工作時序方式進(jìn)行程序編寫,借助仿真圖表、虛擬儀器等工具對A/D轉(zhuǎn)換的數(shù)據(jù)進(jìn)行測量并對失調(diào)誤差、增益誤差、微分非線性、積分非線性和轉(zhuǎn)換時間等重要參數(shù)進(jìn)行了詳細(xì)分析。結(jié)果表明:使用Proteus軟件可對A/D轉(zhuǎn)換過程進(jìn)行定性分析,將抽象的A/D轉(zhuǎn)換器技術(shù)指標(biāo)直觀化、形象化展現(xiàn)出來,有助于學(xué)生更好地理解A/D轉(zhuǎn)換過程。The main technical indicators of A/D converter were analyzed and studied with an example from A/D converter TLC2543 which is controlled by using SCM.It was completed the construction of the A/D converter circuit under the Proteus software.The programming based on the operation sequence of the chip is put forward.With the aid of the simulation tools such as virtual instrument,simulation charts provided by Proteus,the important parameters of circuit such as offset error,gain error,differential nonlinearity(DNL),integral nonlinearity (INL) and conversion time are analyzed detailedly.Simulation results show that the A/D conversion process can be qualitatively analyzed and visualized the abstract indicators of A/D.The system can help students better to understand the SCM conversion process.
為適應(yīng)雙向DC/DC功率變換的電流采樣需求,一種高精度高邊電流采樣電路被提出。其基本思想是在功率電路的高邊串入采樣電阻,借助電流鏡原理并引入偏置電流電路,將雙向電流均轉(zhuǎn)換為正向電壓輸出。通過理論分析與仿真結(jié)合的方法對電流鏡采樣原理及4種不同的偏置電流電路方案進(jìn)行對比,最后通過實驗數(shù)據(jù)驗證了高精度高邊電流采樣電路的有效性。實驗數(shù)據(jù)表明,該采樣電路可在-25~75℃的溫度工作范圍內(nèi),針對-10~＋10 A范圍內(nèi)的電流采樣實現(xiàn)優(yōu)于5%的采樣精度。Current sensing plays an important role in controlling,monitoring or protection functions of power systems.To meet the current sensing requirement of bidirectional DC/DC converters,a high-accuracy bidirectional current sensing circuit is proposed.The proposed current sensing circuit inserts a resistor in the path of the current to be sensed,while the current mirror and biased current circuit are introduced.Therefore,the bidirectional current can be expressed by positive voltage.By theoretical analysis and simulation,the sampling theory is analyzed and four biased current circuits are compared.At last,experimental results verified the proposed method.It is demonstrated that the proposed current sensing circuit can achi...
隨著科技的發(fā)展，人們在日常生活中使用的電器越來越多，電子設(shè)備的電磁兼容性（EMC）也越來越重要。所以，人們對電子設(shè)備的電磁兼容性的要求也越來越嚴(yán)格，越來越規(guī)范。而在市場競爭中，如何降低成本、減少設(shè)備體積，是各電子設(shè)備制造廠家重點研究的課題。通過對開關(guān)電源的EMI濾波電路的類別和相應(yīng)的技術(shù)特點進(jìn)行分析，設(shè)計出一種既能提高性能，又能降低成本的濾波電路。With the development of technology, appliances people use in their daily lives, more and more electronic devices electromagnetic compatibility （ EMC ） has become increasingly important. So, people electromagnetic compatibility requirements of electronic devices have become increasingly stringent, more and more standardized. The competition in the market, how to reduce costs, reduce equipment size, is the subject of the electronic equipment manufacturer focused on research. Through the technical characteristics of the respective category and the EMI filter circuit switching power supply is analyzed both designed to improve a performance of the filter circuit can reduce the cost.
摘要：介紹了以FreeModbus協(xié)議找在嵌入式搶占實時操作系統(tǒng)μC/OS-l的STM32平臺上，成功實現(xiàn)了Modbus協(xié)議的移植。通過詳細(xì)分析FreeModbus協(xié)議花并編寫STM32F103VET6微處理器的底層驅(qū)動，成功實現(xiàn)了工業(yè)Modbus協(xié)議RTU和ASCll兩種模式的通信功能。測試結(jié)果表明，在實際工業(yè)生產(chǎn)控制和儀表開發(fā)中，應(yīng)用Freemodbus協(xié)議，完全符合工業(yè)數(shù)據(jù)采集、實時控制和數(shù)據(jù)處理等廠級重復(fù)性和精確度要求，在一定程度上降低了工業(yè)儀表開發(fā)的周期及成本。關(guān)鍵詞：實時操作系統(tǒng)，uC/OS-ll，F(xiàn)reeModbus，Modbus協(xié)議，STM32Abstract:This paper introduces FreeModbus stack transplanted to the STM32 platform which has been embedded in the preemptive real-time operating system uC/OS-ll，in order that the transplantation of the Modbus protocol is successfuly im-plemented.The FreeModbus stack is analyzed in detail and STM32F103VET6 microprocessor underlying driver is writed，so that the two Modbus industrial communication function RTU and ASCll are successfully realized.Keywords:time operating system，uC/OS-ll，.FreeModbus，Modbus協(xié)議，STM32
