Lecture16-Ratioed+Dynamic

Lecture16-Ratioed+Dynamic - EE141 1 EE141 EECS141 1...

This preview shows pages 1–7. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: EE141 1 EE141 EECS141 1 Lecture #16 EE141 EECS141 2 Lecture #16 Project Phase 1 Done – Thanks for the timely response. Phase 2 to be announced We – Launched on Fr. Hw 6 due on Fr. EE141 2 EE141 EECS141 3 Lecture #16 Last lecture Pass transistor logic CMOS Layout Today’s lecture Ratioed Logic Dynamic Logic Reading (Ch 6) EE141 EECS141 4 Lecture #16 EE141 3 EE141 EECS141 5 Lecture #16 EE141 EECS14 6 #16 Goal: build gates faster/smaller than static complementary CMOS EE141 4 EE141 EECS141 7 Lecture #16 Rising and falling delays aren’t the same Calculate LE for the two edges separately For tpLH: C gate = WC G C inv = (3/2)WC G LE LH = EE141 EECS141 8 Lecture #16 What is LE for t pHL ? Switch model would predict R eff = R n ||R p Would that give the right answer for LE? EE141 5 EE141 EECS141 9 Lecture #16 Time constant is smaller, but it takes more time to complete 50% V DD transient (arguably) Rp actually takes some current away from discharging C v o (t)/V DD t Rp=Rn Rp=2Rn Rp=4Rn Rp= ∞ EE141 EECS141 10 Lecture #16 Think in terms of the current driving C load When you have a conflict between currents Available current is the difference between the two In pseudo-nMOS case: (Works because Rp >> Rn for good noise margin) EE141 6 EE141 EECS141 11 Lecture #16 For t pHL (assuming R sqp = 2R sqn ): R gate = R n /(1-Rn/Rp) = 2Rn R inv = R n C gate = WC G C inv = 3WC G LE HL = LE is lower than an inverter!...
View Full Document

{[ snackBarMessage ]}

Page1 / 22

Lecture16-Ratioed+Dynamic - EE141 1 EE141 EECS141 1...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online