4 }8 v! M0 W5 ]/ G- Y; U(3) 如果gate=darin=high-voltage,+ L6 F2 ?# {$ x9 d/ d
這樣的單位電流會大到不行吧! 1 p6 |2 @& Z5 R% X6 v) j0 HId = kn'W/L * (vgs-vt)2 c& [ S2 B8 `2 B- |4 H. e6 X+ b; p$ O
所以通常是case2會是要考慮的問題, 9 a/ H9 x3 ]% z5 ]/ N不過hot-electron就是可靠度的問題囉。8 V! d" V. @1 i. W8 L+ r% [. b
n.n作者: ywliaob 時間: 2007-10-17 04:43 PM 標題: 回復 4# 的帖子 Vds 太大 只要不超過他的breakdown voltage (3.3V device 大概7V) ( I3 y ?& h: w* g5 sdevice 仍然可以操作 但是會有一些問題自己要去評估! m" c1 d F0 S/ }
如 CLM 造成的Idsat 是否穩定, 元件可靠度可以超過10年嗎 (DC) ! D! G. Y2 f3 i9 o& V& g有可能元件仍然可以操作但是 一天之後就掛了 5 Z6 j+ g6 Q4 ]1 T, _% m& X! e& X( h
基本上 好的device增加L 並不會增加BV z/ c; k# A& T0 n T8 @1 d除非是punchthrough 情況下 增加L 才會增大BV~~~: Y1 N5 u% E0 I& ]
延長contact 至poly的距離 可以增加 BV 有點類似 LDD的功用作者: ainge 時間: 2007-10-25 02:42 PM
If you can see the TSMC on-line reliability information, 5 J% G9 n7 Z5 X( O. i2 V% o% T, w/ yYou will find that there are two major fators as VDD is larger than 3.3V Z: a8 w0 O% U7 D
The first is GOI and the other is HCI. ) F- s7 w! `/ l' YGOI is related to Vgs bias, and HCI is related Vds bias. 1 d5 W% a7 r4 l9 y* n% F) t ~5 EHCI issue can be improved by increase L length. Because this can reduce hot carrier effect in MOS channel. ; S' m0 i. k8 a1 ?9 lBut GOI issue don't have effective to overcome it. GOI is also related to the total gate oxide area size. if you can reduce total gate oxide area size, this factor can be improved.. m+ c& G) I% V
If you use tsmc 0.18um process 3.3 component, 3.9V may be well used.作者: monkeybad 時間: 2007-10-26 10:43 AM
OP的MOS都是SMIC0.13 for 3.3V製程 5 h6 d3 f: z3 d* x* {$ m( Z. z為了要讓輸出Swing能到4V和1V 我OP的VDD拉高到5V 然後我為了閃VDS的rule - x& p: |, v' K+ ^. g7 f; ?$ q' T在上面又多疊接一級PMOS 經過模擬後檢查每顆MOS的VGS,VDS 都有小於3.5V 5 d4 H0 A" {9 i' l( n* @& DVIDEO Buffer採用Inverting的接法 放大兩倍 + G8 D* [: X; u) y
請問這樣會有問題嗎?$ I1 E0 j/ X" l
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[ 本帖最後由 monkeybad 於 2007-10-26 10:44 AM 編輯 ]作者: wuwen 時間: 2007-10-27 04:58 PM 標題: Reply To Monkeybad Again, below is based upon my first glance of the circuit.$ Y, x7 _/ G5 ~) R
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The PMOS on the left hand leg is diode connected, hence, the operating points; [2 F/ k0 R. C, d: D& F* T
of this circuit would be determined by the tail current of the OPAMP. % ?2 U6 v$ T+ z: V 3 E# ]* N4 b L: WAgain, if you need to power down this circuit, high voltage protection would be challenging.作者: monkeybad 時間: 2007-10-31 03:40 PM
Hi! WUWEN ! t$ [1 Y4 ]8 Y$ g) S$ K/ XYes, you're right that to power down this circuit is a problem." M; q" S8 E! n5 h8 z) ]5 }
Thanks for reminding me this issue.: C \5 ^/ @& _! u* A0 i
A straight way I think is that directly turn off the 5V-VDD to 0. , ^; N) f6 u. Q# DBut this may need a separated power line. ( z- E+ r7 U b A$ Z" g& h9 u! L1 k
[ 本帖最後由 monkeybad 於 2007-10-31 03:41 PM 編輯 ]作者: yhchang 時間: 2008-1-12 02:05 AM 標題: 回復 1# 的帖子 想要增加 MOS的耐壓程度 以我目前所知, 可以朝兩個方向去思考 ]- T0 U; S% A
1. 使用 厚oxide的 device 0 f2 I4 A5 M5 p% f2. 提高該MOS的 channel length9 X! g5 f H9 e, n' ~& j; v
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在你的chip當中 輸入輸出介面 MOS的 drain與source比較有機會接到高壓0 o9 U; `* Y( y9 F
所以一定要用 厚oxide的 MOS 並且提高 Length到一定的程度 ( 大概是, a8 J) A5 E- u+ N. P' o% M
minimum length的2倍到3倍) 這樣才可以防止 hot-carrier effect.4 |9 {8 z0 K0 h6 N2 e- V+ w