<font style="BACKGROUND-COLOR: #941ae6;"></font><img src="attachments/dvbbs/2006-10/2006102413282598186.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2006-10/2006102413282598186.jpg\');}" onmousewheel="return imgzoom(this);" alt="" /><br/><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 31.5pt; TEXT-ALIGN: left; mso-layout-grid-align: none; mso-char-indent-count: 3.0;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"></span> </p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 31.5pt; TEXT-ALIGN: left; mso-layout-grid-align: none; mso-char-indent-count: 3.0;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;">该pin连接上管驱动器的自举电容,当上管截止而下管导通时,VDD给电容充电,充电回路:VDD-IC内部二极管-电容-中点-下管D/S-GND,BOOT端将得到12V的电压,电容两端电压也会是12V,当上管导通而下管截止时,中点电压升到12V,BOOT端的电压将会是这两个电压相加得到24V,<u><strong>实际上我们不用示波器,仅仅用普通电表测量电路时,</strong></u>上管的D-S所控制的电压高于下管的D-S所控制的电压,进而上管的G极电压高于下管的G极电压<strong>。</strong><br/> <p></p></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> 上面带下划线的话有点问题,和新照交流后,觉得应该这样说:</span></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;">用示波器看上管栅极波形,Vp电压为24V,用万用表量一般平均电压2~3</span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;">V</span></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;">用示波器看下管栅极波形,Vp电压为12V,用万用表量一般平均电压8~9</span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;">V</span></span></span></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;">为什么会高低刚好相反呢?想必是占空比问题吧</span></span></span><br/> <p></p></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span><span style="mso-spacerun: yes;"> </span></span><b style="mso-bidi-font-weight: normal;"><span style="COLOR: #ff6600; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;">VCC</span></b><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span>(pin14)<span style="mso-spacerun: yes;"> </span>IC工作电压<span style="mso-spacerun: yes;"> </span><b><p></p></b></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span><span style="mso-spacerun: yes;"> </span></span><b style="mso-bidi-font-weight: normal;"><span style="COLOR: #ff6600; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;">GND</span></b><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span>(pin 3)<span style="mso-spacerun: yes;"> </span><b><p></p></b></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span><span style="mso-spacerun: yes;"> </span></span><b style="mso-bidi-font-weight: normal;"><span style="COLOR: #ff6600; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"> VCC</span></b><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span>(pin 5)<span style="mso-spacerun: yes;"> </span>IC内部驱动MOSFET的电源,输出级VCC<b><br/> <p></p></b></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span><span style="mso-spacerun: yes;"> </span></span><b style="mso-bidi-font-weight: normal;"><span style="COLOR: #ff6600; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"> GND</span></b><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span>(pin 6)<b><br/> <p></p></b></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><p> </p></span></p><p> </p><p></p><p> </p><p></p><p> </p><p></p><p> </p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span><font size="4"><strong>各工作点实际电压分析</strong></font><br/> <p></p></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><span style="mso-spacerun: yes;"> </span>1,启动电压 <p></p></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-hansi-font-family: Arial; mso-bidi-font-family: 宋体; mso-ansi-language: ZH-CN; mso-font-kerning: 0pt; mso-bidi-font-size: 10.5pt;"><p> </p></span></p><p> </p><p></p><p> </p><p></p><p> </p><p></p><p> </p><p></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><p><font face="Times New Roman"> </font></p></span></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><p><font face="Times New Roman"> </font></p></span></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p><font face="Times New Roman"> </font></p><p></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><span style="mso-spacerun: yes;"><font face="Times New Roman"> </font></span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman';">声明:纯属愚昧的个人理解,望有高手出来批评!</span></p><br/>
[此贴子已经被作者于2006-10-25 13:25:04编辑过]
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