標題: CMOS工艺下bandgap 负温度系数器件，为什么使用PNP管而不是用二极管？ [打印本頁] 作者: scy8080 時間: 2012-2-3 02:59 PM 標題: CMOS工艺下bandgap 负温度系数器件，为什么使用PNP管而不是用二极管？ CMOS工艺下bandgap 负温度系数器件，为什么使用PNP管而不是用二极管？作者: hoodlum 時間: 2012-2-3 10:59 PM
小弟的看法是) K- J& V4 T' \9 ~
會不會是標準CMOS的製程裡 ! b/ }2 o7 C: o' O4 u3 O9 K無法做出二極體, 只能用寄生的7 c! _% W' J% B
vertical PNP呢???作者: leo911759 時間: 2012-2-8 04:02 PM
其實也是有的。 U- @$ k% a3 M" {4 h8 B0 n" S' v. I$ B' [6 u/ A
有一些Paper就是用Diode，或是NPN。 0 m( I: a6 d/ g& h3 X1 d8 T! f: h+ p& G& {. W" j5 _
而會用PNP 是因為早期CMOS製程中，只能寄生等效PNP電路。 " X% i5 u9 b) e 8 x( n# v6 `- H4 h, G其中的寄生等效Diode會有Latch-up的問題。 * a( u% M0 v% \- K- V# a% l1 t- o' G$ x) S/ v) R: I/ t6 V
這是製程受限的關係，比較先進的製程就沒這種問題了。作者: patrick02046 時間: 2012-2-9 01:24 PM
在EDA Board 抓的資訊， 參考一下: & \; j! K% ], F0 R5 _5 M( ` 0 y$ y! w- C( II believe that what you are getting at is that there is a specific structure of P+/Nwell/Psub that is used for Y% @6 n/ c2 N5 z, t( i " \ \8 _5 O, Tthe "bipolar", so you are asking why use that structure rather than simply a P+/Nwell "diode". Here is my take 3 N! m4 |# V8 H7 A; T5 x6 J
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- r2 Z: B2 |" R* u1- The "bipolar" will simulate more accurately than the "diode", since it will include the substrate current 5 d9 ]- N) J% k! @
! Z G G+ T$ Othat is probably not modeled for the "diode".- F/ h' o/ u. D1 S+ c1 h
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2- There usually is a specific structure for the "bipolar" that has characterization data available. When $ W6 h! {" ]0 w( g+ C
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building a bandgap structure, the good characterization is needed in order to properly determine the tempco of . ?9 S1 M1 o. |" n/ _ . E: @( c! R0 u1 ^3 U3 V, [9 ithe Base-emitter voltage. 5 Q4 S4 _+ S6 L+ _% B ! v/ J/ S/ t! X. N% N6 }6 r' Y3- The additional structure of the bipolar should help prevent current injection into other substrate tied 9 y+ V+ n I) c2 f0 |3 [2 u. a; C! s" ^) x( @& c3 T
devices. A2 \ J% {2 v1 n
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F: @8 F6 G% [/ U3 i1 m5 u- cThere is, of course, nothing preventing the use of a P+/Nwell diode in your application.作者: luckyhuihui666 時間: 2012-4-13 08:06 PM
主要原因就是二极管不准确……