基于CPLD的可編程寬帶放大器的設(shè)計

摘要：本設(shè)計以AT89C51單片機和CPLD為控制核心，利用高速可編程增益放大器THS7001和可變增益放大器AD603，設(shè)計了一種抗噪聲能力強、具有自動增益控制且增益范圍較寬的可編程寬帶放大器。其中AT89C51單片機主要完成讀取鍵值、控制增益和顯示功能；而CPLD則作為總線控制器，控制鍵盤、液晶和A/D轉(zhuǎn)換器與AT89C51單片機之間的數(shù)據(jù)交換；此外，可控增益放大器以高速可編程增益放大器THS7001和可變增益放大器AD603為核心，AT89C51單片機控制高速可編程增益放大器THS7001實現(xiàn)增益粗調(diào)，并通過D/A轉(zhuǎn)換控制可變增益放大器AD603實現(xiàn)增益細調(diào)，從而使總增益能夠在一個比較理想的寬頻帶范圍內(nèi)線性變化。

關(guān)鍵詞：放大器；寬帶；可編程；可變增益；抗噪聲；自動增益

Design of a programmable wideband amplifier at the base of CPLD

Abstract: Taking AT89C51 microcontroller and CPLD as the controlling core, and using the high speed programmable-gain amplifier THS7001 and the variable-gain amplifier AD603, the paper designs one kind of programmable wideband amplifier, which has strong anti-noise ability and automatic-gain control and also increases the scope the of automatic-gain wide. During the paper, AT89C51 microcontroller mainly reads the key value and controllers gain and function of the display. At the same time, as the controller of the bus, CPLD controls the data exchange between the keyboard, the liquid crystal or the A/D converter and AT89C51 microcontroller. In addition, the high speed programmable-gain amplifier THS7001 and the variable-gain amplifier AD603 is the core of controlled-gain amplifier. AT89C51 microcontroller controls the high speed programmable-gain amplifier THS7001 to change at a large scope of gain and through D/A converter controls the variable-gain amplifier to change at a small scope of gain. Thus, it is able that the overall gain has a linear variation at a quite ideal scope of wideband.
Key words: amplifier; wideband; programmable-gain; variable-gain; anti-noise; automatic-gain

目    錄
摘要……………………………………………………………………………………………1
1 引言 3
2 系統(tǒng)總體方案設(shè)計 4
3 系統(tǒng)芯片的選擇及分析 5
3.1 系統(tǒng)輸入級芯片的選擇 5
3.2 系統(tǒng)輸出級芯片的選擇 6
3.3 增益控制芯片的選擇 6
3.3.1 AD603的簡介及選用分析 6
3.3.2 THS7001的簡介及選用分析 7
3.4 系統(tǒng)增益分析 7
4 提高系統(tǒng)抗噪聲性能的措施 7
5 系統(tǒng)硬件電路設(shè)計 8
5.1 增益控制電路設(shè)計 8
5.2 峰值檢波電路設(shè)計 9
6 系統(tǒng)軟件設(shè)計 10
6.1 系統(tǒng)程序總體設(shè)計 10
6.2 CPLD程序設(shè)計 11
6.3 單片機程序設(shè)計 12
結(jié)束語 14
參考文獻……………………………………………………………………………………14