發(fā)布時(shí)間：2018-11-14 13:49

【摘要】：振蕩器的應(yīng)用十分廣泛,從誕生到至今一直充分應(yīng)用在電子、通信、儀器儀表、航海航空以及醫(yī)學(xué)裝備等領(lǐng)域。隨著集成電路工藝的發(fā)展,主流的CMOS制造工藝也在不斷地進(jìn)步,MOS管的尺寸從亞微米進(jìn)一步減小到幾十納米的量級,集成電路的功耗和面積也在不斷減小,振蕩器作為開關(guān)電源中的核心組成模塊,對其性能指標(biāo)的要求變得越來越高,設(shè)計(jì)者在設(shè)計(jì)、分析和仿真過程中面臨的問題和挑戰(zhàn)也越來越多,為了滿足使用的要求,電路設(shè)計(jì)者開始尋求在功耗、速度、噪聲、穩(wěn)定性等方面達(dá)到的平衡,這促使著對電路結(jié)構(gòu)的不斷改進(jìn)。因此,在CMOS工藝上,通過優(yōu)化電路結(jié)構(gòu)和增加拓展功能實(shí)現(xiàn)電路性能的提升和完善具有十分重要的現(xiàn)實(shí)意義。本論文從上述角度出發(fā),主要研究張弛振蕩器的結(jié)構(gòu)和功能。文中設(shè)計(jì)目標(biāo)為：振蕩器的中心頻率為200kHz,溫度在-40℃～125℃之間變化時(shí),頻率隨溫度的最大偏移量小于1%.外同步范圍200kHz～1 MHz.具體研究內(nèi)容和創(chuàng)新性成果如下：(1)當(dāng)芯片的工作溫度發(fā)生改變時(shí),振蕩器的頻率也會(huì)受到影響。基于張弛振蕩器的結(jié)構(gòu),分析頻率精確度的主要影響因素。在一定溫度范圍內(nèi),分別對張弛電容的充電電流和比較器的門限電壓進(jìn)行溫度補(bǔ)償,并通過在比較器的結(jié)構(gòu)上增加一個(gè)正反饋回路對比較器進(jìn)行優(yōu)化,實(shí)現(xiàn)了振蕩器頻率線性度和頻率抖動(dòng)的合理折衷,得到高精度和高穩(wěn)定性的振蕩器。(2)在溫度補(bǔ)償?shù)恼袷幤鹘Y(jié)構(gòu)上,對其功能進(jìn)行拓展,拓展功能包括外同步功能、降頻功能和展頻功能。當(dāng)芯片處于外同步工作狀態(tài)下時(shí),一方面通過外同步信號產(chǎn)生穩(wěn)定的使能信號提供給芯片的其他模塊使用,另一方面產(chǎn)生同步時(shí)鐘信號,使芯片整個(gè)系統(tǒng)以外部時(shí)鐘頻率工作；當(dāng)芯片發(fā)生短路時(shí),振蕩器會(huì)自動(dòng)降頻,通過降頻降低了芯片在短路狀態(tài)的功耗,并且當(dāng)芯片從短路狀態(tài)恢復(fù)時(shí),由于軟啟動(dòng)需要較長的時(shí)間,降頻大大縮短了芯片重新進(jìn)入正常工作狀態(tài)的時(shí)間；最后本文采用兩種方法實(shí)現(xiàn)展頻功能,分別是周期性的改變振蕩器的充電電容和門限電壓的大小,通過頻率擴(kuò)展功能,抑制了電磁干擾。
[Abstract]:The oscillator has been widely used in the fields of electronics, communication, instrumentation, navigation, aviation and medical equipment. With the development of integrated circuit technology, the mainstream CMOS manufacturing process is also progressing. The size of MOS tube is further reduced from submicron to tens of nanometers, and the power consumption and area of integrated circuit are also decreasing. As the core component module of switching power supply, oscillator has become more and more demanding for its performance index, and designers are facing more and more problems and challenges in the process of design, analysis and simulation. Circuit designers begin to seek balance in power consumption, speed, noise, stability and so on, which leads to continuous improvement of circuit structure. Therefore, in CMOS process, it is very important to improve the circuit performance by optimizing the circuit structure and adding extended functions. This thesis mainly studies the structure and function of Zhang Chi oscillator from the above point of view. The design goal is: the center frequency of the oscillator is 200kHz, and the maximum deviation of the frequency with temperature is less than 1 when the temperature varies from -40 鈩，

本文編號：2331340