2022年医学专题—第6章-脉冲信号的产生和整形.pptVIP免费

一一555定时器的电路(diànlù)结构由以下几部分组成：一1一一一一一一一一一一一2一一一一一一一一一6.2集成(jíchénɡ)555定时器（3）基本(jīběn)RS触发器、（4）放电三极管T及缓冲器G。第一页，共三十五页。第二页，共三十五页。一一一一(gōngzuò)一一一1一4一一一一一一一一RD一一一RD一一一一一一一一一一(qítā)一一一一一一一一一一一vo一一一一一一一一一一一一一一一一一一一（2）5一一一一一一一一一一一一一一一一一C1一C2一一一一一一一一2/3VCC一1/3VCC一一3一2一一一一一一一一6一一一一一一一一一一一一一一一一一一一一C1一C2一一一一一一一一RS一一一一一一一一一一一第三页，共三十五页。6.2一一(màichōng)一一一一一一----一一一一一一一一一一——一一一(chǎnshēng)一一一一一一一一一一一一一．用555定时器构成的多谐振荡器1.一一一一一一一一一第四页，共三十五页。2.一一一一(pínlǜ)一一一一1一一一(diànróng)一一一一T1一一一一一一一一一一（2）电容放电(fàngdiàn)时间T2（3）电路振荡周期TT=T1+T2=0.7(R1+2R2)C（4）电路振荡频率f（5）输出波形占空比q)()()0()(ln111TvvvvTCCCCCRR)(7.021CCCCCCCCVVVV3231ln1CRT227.0CRRTf)2(43.1121212112RRRRTTq第五页，共三十五页。一一一一一一一一一一一一一一一(diànlù)一一一一一一一一一一一一一一一一一一一C一一一一一一一一一一一一一一一一一(yīɡè)一一一一一一一一一一一一一一一一一一一一可计算(jìsuàn)得：T1=0.7R1CT2=0.7R2C占空比：21121121117.07.07.0RRRCRCRCRTTTTTq第六页，共三十五页。一一一一一一(jīngtǐ)一一一一一1.一一一一一一一一一一一一一一一一一一f=fs一一一一一一一一一一一一一一一(diànkàng)X=0一一f=fp一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一fs≈fp≈f0一一一一一一一一一一一一一一一一一一一一一f0一一一一一一一一一一一10-10一10-11一第七页，共三十五页。2.一一(shíyīng)一一一一一一一一1一一一一一一一R1、R2的作用——使两个反相器在静态时都工作在转折区，成为具有很强放大能力的放大电路。对于TTL门，常取R1=R2=0.7～2kΩ，若是CMOS门则常取R1=R2=10～100MΩ；C1=C2是耦合电容。石英晶体工作在串联谐振频率f0下，只有频率为f0的信号才能通过，满足振荡(zhèndàng)条件。因此，电路的振荡(zhèndàng)频率=f0，与外接...