UCES£½0.6V¡£ÊÔÎÊ£ºµ±¸ºÔصç×èRL£½¡ÞºÍRL£½3k¦¸Ê±µç·µÄ×î´ó²»Ê§ÕæÊä³öµçѹ¸÷Ϊ¶àÉÙ·ü£¿
½â£ºÓÉÓÚICQ£½2mA£¬ËùÒÔUCEQ£½VCC£ICQRc£½6V¡£
¿ÕÔØÊ±£¬ÊäÈëÐźÅÔö´óµ½Ò»¶¨·ùÖµ£¬µç·Ê×ÏȳöÏÖ±¥ºÍÊ§Õæ¡£¹Ê Uom?UCEQ?UCES2'ICQRL?3.82V
RL?3k?ʱ£¬µ±ÊäÈëÐźÅÔö´óµ½Ò»¶¨·ùÖµ£¬µç·Ê×ÏȳöÏÖ½ØÖ¹Ê§Õæ¡£¹Ê
Uom?
2.12ÔÚͼP2.10Ëùʾµç·ÖУ¬Éèijһ²ÎÊý±ä»¯Ê±ÆäÓà²ÎÊý²»±ä£¬ÔÚ±íÖÐÌîÈë¢ÙÔö´ó¢Ú¼õС»ò¢Û»ù±¾²»±ä¡£
²ÎÊý±ä»¯ RbÔö´ó RcÔö´ó RLÔö´ó
½â£º´ð°¸Èç½â±íP2.12Ëùʾ¡£
½â±íP2.12Ëùʾ
²ÎÊý±ä»¯ RbÔö´ó RcÔö´ó RLÔö´ó
2.13 µç·ÈçͼP2.13Ëùʾ£¬¾§Ìå¹ÜµÄ?£½100£¬rbb'=100¦¸¡£
µÚ¶þÕÂÌâ½â£13
2?2.12V
IBQ UCEQ ? Au Ri Ro IBQ ¢Ú ¢Û ¢Û UCEQ ¢Ù ¢Ú ¢Û ? Au¢Ú ¢Ù ¢Ù Ri ¢Ù ¢Û ¢Û Ro ¢Û ¢Ù ¢Û ?¡¢RiºÍRo£» £¨1£©Çóµç·µÄQµã¡¢Au £¨2£©ÈôµçÈÝCe¿ªÂ·£¬Ôò½«ÒýÆðµç·µÄÄÄЩ¶¯Ì¬²ÎÊý·¢Éú±ä»¯£¿ÈçºÎ±ä»¯£¿
ͼP2.13
½â£º£¨1£©¾²Ì¬·ÖÎö£º
UBQ?Rb1?VCC?2V Rb1?Rb2Rf?ReIEQ?1mA IEQ?IBQ?UCEQUBQ?UBEQ
?10¦Ì A 1???VCC?IEQ(Rc?Rf?Re)?5.7V ¶¯Ì¬·ÖÎö£º
rbe?rbb'?(1??)26mV?2.73k?IEQ?(Rc¡ÎRL) ?Au????7.7rbe?(1??)RfRi?Rb1¡ÎRb2¡Î[rbe?(1??)Rf]?3.7k?Ro?Rc?5k?
?¼õС£¬A??? £¨2£©RiÔö´ó£¬Ri¡Ö4.1k¦¸£»Auu
'RL¡Ö£1.92¡£
Rf?Re?¡¢RiºÍRo µÄ±í´ïʽ¡£ 2.14 ÊÔÇó³öͼP2.3£¨a£©Ëùʾµç·Qµã¡¢Au
µÚ¶þÕÂÌâ½â£14
½â£ºQµãΪ
IBQ?VCC?UBEQR1?R2?(1??)Rc
ICQ?? IBQ UCEQ?VCC?(1??)IBQRc?¡¢RiºÍRoµÄ±í´ïʽ·Ö±ðΪ Au????R2¡ÎR3 , R?r¡ÎR , R?R¡ÎR Auibe1o23rbe
?¡¢RiºÍRoµÄ±í´ïʽ¡£Éè¾² 2.15 ÊÔÇó³öͼP2.3£¨b£©Ëùʾµç·Qµã¡¢Au̬ʱR2ÖеĵçÁ÷Ô¶´óÓÚTµÄ»ù¼«µçÁ÷¡£
½â: Qµã£º
IBQ?(R2VCC?UBEQ)[R2¡ÎR3£«(1£«?)R1]R2?R3
ICQ?? IBQ UCEQ?VCC?ICQRc?UBEQ?¡¢RiºÍRoµÄ±í´ïʽ·Ö±ðΪ Au??? R4 Aurbe Ri?R1¡Îrbe 1??Ro?R4
?¡¢RiºÍRoµÄ±í´ïʽ¡£Éè¾² 2.16 ÊÔÇó³öͼP2.3£¨c£©Ëùʾµç·Qµã¡¢Au
µÚ¶þÕÂÌâ½â£15
̬ʱR2ÖеĵçÁ÷Ô¶´óÓÚT2¹ÜµÄ»ù¼«µçÁ÷ÇÒR3ÖеĵçÁ÷Ô¶´óÓÚT1¹ÜµÄ»ù¼«µçÁ÷¡£
½â£ºÁ½Ö»¾§Ìå¹ÜµÄ¾²Ì¬µçÁ÷¡¢¹Üѹ½µ·ÖÎöÈçÏ£º
IBQ1?VCC?UBEQ1R?UBEQ11?R2R 3ICQ2? ICQ1?? IBQ1
UCQ2?VCC? ICQ2R4
U2BQ2?RR?R(VCC?UBEQ1)?UBEQ112UCEQ1?UBQ2£UBEQ2UCEQ2?UCQ2£UBQ2?UBEQ2A?u¡¢RiºÍRoµÄ±í´ïʽ·ÖÎöÈçÏ£º ?rbe21?A???1??2u1rbe1A?2??2R4ur be2 A?u?A?u1A?u2
Ri?R2¡ÎR3¡Îrbe1 Ro?R4
2.17 ÉèͼP2.17Ëùʾµç·Ëù¼ÓÊäÈëµçѹΪÕýÏÒ²¨¡£ÊÔÎÊ£º ͼP2.17
£¨1£©A?u1=U?o1/U?i¡Ö? A?u2=U?o2/U?i¡Ö? £¨2£©»³öÊäÈëµçѹºÍÊä³öµçѹui¡¢uo1¡¢uo2 µÄ²¨ÐΣ»
µÚ¶þÕÂÌâ½â£16