THE INVERTERS

DIGITAL GATES Fundamental Parameters l Functionality l Reliability, Robustness l Area l Performance »Speed (delay) »Power Consumption »Energy Digital Integrated Circuits© Prentice Hall 1995 Introduction

Noise in Digital Integrated Circuits Digital Integrated Circuits© Prentice Hall 1995 Introduction

DC Operation: Voltage Transfer Characteristic Digital Integrated Circuits© Prentice Hall 1995 Introduction

Mapping between analog and digital signals Digital Integrated Circuits© Prentice Hall 1995 Introduction

Definition of Noise Margins Digital Integrated Circuits© Prentice Hall 1995 Introduction

The Regenerative Property Digital Integrated Circuits© Prentice Hall 1995 Introduction

Fan-in and Fan-out Digital Integrated Circuits© Prentice Hall 1995 Introduction

The Ideal Gate Digital Integrated Circuits© Prentice Hall 1995 Introduction

VTC of Real Inverter Digital Integrated Circuits© Prentice Hall 1995 Introduction

Delay Definitions Digital Integrated Circuits© Prentice Hall 1995 Introduction

Ring Oscillator Digital Integrated Circuits© Prentice Hall 1995 Introduction

Power Dissipation Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS INVERTER Digital Integrated Circuits© Prentice Hall 1995 Introduction

The CMOS Inverter: A First Glance Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverters Polysilicon In Out Metal1 V DD GND PMOS NMOS 1.2  m =2 Digital Integrated Circuits© Prentice Hall 1995 Introduction

Switch Model of CMOS Transistor Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter: Steady State Response Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter: Transient Response Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Properties l Full rail-to-rail swing l Symmetrical VTC l Propagation delay function of load capacitance and resistance of transistors l No static power dissipation l Direct path current during switching Digital Integrated Circuits© Prentice Hall 1995 Introduction

Voltage Transfer Characteristic Digital Integrated Circuits© Prentice Hall 1995 Introduction

PMOS Load Lines V DSp I Dp V GSp =-5 V GSp =-2 V DSp I Dn V in =0 V in =3 V out I Dn V in =0 V in =3 V in = V DD -V GSp I Dn = - I Dp V out = V DD -V DSp V out I Dn V in = V DD -V GSp I Dn = - I Dp V out = V DD -V DSp Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter Load Characteristics Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter VTC Digital Integrated Circuits© Prentice Hall 1995 Introduction

Simulated VTC Digital Integrated Circuits© Prentice Hall 1995 Introduction

Gate Switching Threshold Digital Integrated Circuits© Prentice Hall 1995 Introduction

MOS Transistor Small Signal Model Digital Integrated Circuits© Prentice Hall 1995 Introduction

Determining V IH and V IL Digital Integrated Circuits© Prentice Hall 1995 Introduction

Propagation Delay Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter: Transient Response Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverter Propagation Delay Digital Integrated Circuits© Prentice Hall 1995 Introduction

Computing the Capacitances Digital Integrated Circuits© Prentice Hall 1995 Introduction

CMOS Inverters Polysilicon In Out Metal1 V DD GND PMOS NMOS 1.2  m =2 Digital Integrated Circuits© Prentice Hall 1995 Introduction

The Miller Effect Digital Integrated Circuits© Prentice Hall 1995 Introduction

Computing the Capacitances Digital Integrated Circuits© Prentice Hall 1995 Introduction

Impact of Rise Time on Delay Digital Integrated Circuits© Prentice Hall 1995 Introduction

Delay as a function of V DD Digital Integrated Circuits© Prentice Hall 1995 Introduction

Where Does Power Go in CMOS? Digital Integrated Circuits© Prentice Hall 1995 Introduction

Introduction to VLSI Design© Steven P. Levitan 1998 Introduction MOS Transistors (again) l Device Equations: »Off (ignore sub-threshold): Vgs < Vt – Ids = 0 »Linear: Vgs > Vt & |Vdg|<|Vth| »Saturation:Vgs>Vt & |Vgd| > |Vth|

Introduction to VLSI Design© Steven P. Levitan 1998 Introduction Current Flow in an Inverter R = 100 Ohms C = 0.1 pf (100 ff)

Introduction to VLSI Design© Steven P. Levitan 1998 Introduction Spice Deck *** SPICE DECK created from inv1.sim, tech=scmos M CMOSP L=3.0U W=6.0U M CMOSN L=3.0U W=6.0U R R R C PF *vin 4 *vout 6 vdd 1 0 dc 5v ****************V1 V2 Del Tr Tf Tpw Period vin 4 0 pulse (0v 5v 5ns 5ns 5ns 5ns 50ns)

Dynamic Power Dissipation Energy/transition = C L * V dd 2 Power = Energy/transition *f =C L * V dd 2 * f Need to reduce C L, V dd, andf to reduce power. VinVout C L Vdd Not a function of transistor sizes! Digital Integrated Circuits© Prentice Hall 1995 Introduction

Impact of Technology Scaling Digital Integrated Circuits© Prentice Hall 1995 Introduction

Technology Evolution Digital Integrated Circuits© Prentice Hall 1995 Introduction

Technology Scaling (1) Minimum Feature Size Digital Integrated Circuits© Prentice Hall 1995 Introduction

Technology Scaling (2) Number of components per chip Digital Integrated Circuits© Prentice Hall 1995 Introduction

Propagation Delay Scaling Digital Integrated Circuits© Prentice Hall 1995 Introduction

Technology Scaling Models Digital Integrated Circuits© Prentice Hall 1995 Introduction

Scaling Relationships for Long Channel Devices Digital Integrated Circuits© Prentice Hall 1995 Introduction

Scaling of Short Channel Devices Digital Integrated Circuits© Prentice Hall 1995 Introduction