Interconnect delay. Interconnect delay. Elmore Delay. Elmore Delay. Elmore Delay. Elmore Delay

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Howard Benson
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1 ercoec delay ercoec delay umed model harge i o The rasie ouu volage is dlh e l dlh. 69 ou( e More accurae ha lumed model More diicul o solve or large eed ull-scale SPE simulaio March 009 March 009 Sigle lie model o useul or geeralized ree eworks s i i -ree roery: Uique resisive ah bewee he source ode s ad ay oher ode i o he ework ah resisace ii Examle: s i i March 009 March 009 s i Assumig: Each ode is iiially discharged o groud A se iu (ulse is alied a ime 0 a ode s The Elmore delay a ode i is: -ree roery: Exeded o shared ah resisace ik : ik j s.. ( [ ah( s i ah( s k] Examle: j i τ Di is a aroximaio: i is equivale o irs-order ime cosa o he ework Prove acceable Powerul mechaism or a quick esimae k k ik March 009 March 009 6

2 Examles d ( ( d ( d j j k ( d or March March ercoec Delay ercoec Delay Faou Eecs ies wih mulile loads will have loger delays locks Daa buses orol lies Soluios Wider lies or secial sigals Buers d l r ( c lw c ( l w w a ( rc a l Delay is roorioal o he square o he legh Try o avoid log lies March March ercoec Delay ercoec Delay Avoid log iercoec delays usig buers ercoec resisace 000 µ r.l/w Ω 0.µ ercoec caaciace a lw (lw wire µ 0.µ.0 (000µ 0.µ F risic load caaciace i F Proagaio delay wire 700 F i 700 F 8 s ercoec resisace 00 µ.07 0Ω 0.µ ercoec caaciace wire µ 0.µ.0 (00 µ 0.µ 8 F risic load caaciace i F Proagaio delay wire 0 8 F i 0 F 9 s March 009 March 009

3 ercoec Delay Swichig Delay Avoid log iercoec delays usig wider lies ercoec resisace 000 µ.07 70Ω µ ercoec caaciace wire µ µ.0 (000 µ µ 90 F risic load caaciace i F Proagaio delay wire F i 70 F s The irisic delay o a gae Trasisor sizig ca aec he delay Exrisic caaciaces ca aec he delay March 009 March 009 Delay Deiiios Swichig Delay Fall ime aalysis March 009 March Fall ime aalysis Sauraio Mode Fall ime aalysis iear Mode dou ( k d d d k ( k ( (. k ( ou.9 d ou d ou k ( d ou ou d dou k (( k. ou ( ou ou dou ( ou March March 009 8

4 Fall ime aalysis Fall ime aalysis iear Mode ou k l ( ( ou 9 0 l k(. (. 9 0 l k ( (. l(9 0 k ( (. K l(9 0 ( K k March March Fall ime aalysis ise ime aalysis Fall ime is roorioal o load caaciace ad iversely roorioal o ad k Decreasig he suly volage will icrease he all ime creasig he rasisor widh will icrease k which will reduce he all ime hagig hese hree arameers ca cause colicig goals (. r l(9 0 k ( K (. l(9 0 ( r K k March 009 March 009 ise ime aalysis For equal all imes ad rise imes r K k K K K k W W µ ox µ ox Proagaio Delay As wih iercoec delay, id he equivale resisace ad load caaciace o he rasisor. 69 H eq W µ W µ March 009 March 009

5 Proagaio Delay eq avg( o ( Proagaio delay is he ime or volage o reach hal way oi - so iegrae rom o / eq For he ouu rage we are ieresed i, he rasisor is always i sauraio eq ( AT( ( ( ( d d λ Proagaio Delay eq AT( d λ ( λ l( λ λ λ λ λ λ λ 7λ 8 7 λ 9 λ March 009 March Proagaio Delay oad caaciace Proagaio Delay oad caaciace risic caaciace - sum o caaciaces a drai - GD DB March March Proagaio Delay Proagaio Delay risic caaciace GD is comosed solely o overla caaciace The rasisors are eiher i cuo or i sauraio, so o chael caaciace exiss The acual load caaciace relaive o groud is GDO because o Miller eec Miller eec accous or a icrease i he equivale iu caaciace o a iverig volage amliier due o amliicaio o caaciace bewee he iu ad ouu ermials.69 ( H 0 eq GDO GDO DB DB ex Exrisic caaciace is comosed o wire caaciace ad iu caaciace o aou u caaciace is comosed o overla caaciace ad chael caaciace Overla caaciace is GDO GSO (very small hael caaciace is ox W. Assume wors case March March 009 0

6 Proagaio Delay All caaciaces are roughly roorioal o W Equivale resisace is iversely roorioal o W March 009 6

Design and Application Notes for AP3768 System Solution

Design and Application Notes for AP3768 System Solution licaio oe 039 Desig ad licaio oes for 3768 ysem oluio reared by iu ei ysem Egieerig De.. roducio The 3768 is he geeraio rimary ide egulaio () coroller, which uses ulse Frequecy Modulaio (FM) mehod o realize