High Speed PCB Design and Analysis
®




Agenda


• Today’s High Speed PCB design challenges
• Cadence PCB solution overview
• Demonstration overview
• Summary
• Q&A




2                                            CADENCE DESIGN SYSTEMS, INC.
®




MARKET CONVERGENCE
IS DRIVING DESIGN CONVERGENCE

     MARKET CONVERGENCE                          DESIGN CONVERGENCE


                Communications
                                              Hardware               Software
    Computing




                                 Multimedia




                                                Digital              Analog



                                                    IC               Board
                  Consumer




3                                                          CADENCE DESIGN SYSTEMS, INC.
®




                            High Speed Design Challenges                                                    IC              Board
         1




                                                          • System timing
Clock                                          4
Driver

                                           Setup
                                                   Hold
             2   Tco




                   D0
                        3
                            Flight Time
                                             D0
                                                            – What is the maximum data rate for reliable data transfer?
                                                          • Waveform integrity
                   D1                        D1
                   D2                        D2


             Driving                       Receiving


                 D0           D1          D2
                                                            – Do signals meet applicable electrical requirements?

                                                          • Crosstalk
                                                            – Do the signals interfere with each other?

                                                          • Power and/or ground plane stability
                                                            – Are power voltages at the ICs sufficiently controlled?
                                                          • EMI (differential and common mode)
                                                            – Are critical signals radiating too much energy?
                                                            – Are power planes producing common-mode radiation?


         4                                                                                            CADENCE DESIGN SYSTEMS, INC.
®




PCB System Design Flow and Products
                Communications                                                   Functional
                                                                                  Functional          NC Sim
                                                                                 Verification
                                                                                 Verification       PSpice/AWB
    Computing




                                                                                                  SPECCTRAQuest C
                                   Multimedia
                                                                                 Exploration




                                                PCB Design Infrastructure
                                                                                                                            O
                                                                            C    Design Entry S     Capture CIS             N
                                                                            O                 I     Concept HDL             S
                                                                            N                                               T
                                                                                Floorplanning                               R
                                                                            S                 A                             A
                                                                                                  SPECCTRAQuest
                                                                            T                 N                             I
                     Consumer                                               R                 A                             N
                                                                            A     High-Speed L         Allegro              T
                                                                            I    PCB Layout Y        SPECCTRA
                                                                                                                            M
                IC              Board                                       N                 S                             A
          Digital               Analog                                      T                 I   SPECCTRAQuest             N
                                                                            S                 S                             A
                                                                                      IC                                    G
                                                                                                                            E
                                                                                  Packaging       Advanced Package          R
                                                                                                      Designer

5                                                                                                  CADENCE DESIGN SYSTEMS, INC.
®




                                                                                                          IC              Board
PCB System Design Flow and Products
                Communications                                                   Functional
                                                                                  Functional          NC Sim
                                                                                 Verification
                                                                                 Verification       PSpice/AWB
    Computing




                                                                                                  SPECCTRAQuest C
                                   Multimedia
                                                                                 Exploration




                                                PCB Design Infrastructure
                                                                                                                             O
                                                                            C    Design Entry S     Capture CIS              N
                                                                            O                 I     Concept HDL              S
                                                                            N                                                T
                                                                                Floorplanning                                R
                                                                            S                 A                              A
                                                                                                  SPECCTRAQuest
                                                                            T                 N                              I
                     Consumer                                               R                 A                              N
                                                                            A     High-Speed L         Allegro               T
                                                                            I    PCB Layout Y        SPECCTRA
                                                                                                                             M
                IC              Board                                       N                 S                              A
          Digital               Analog                                      T                 I   SPECCTRAQuest              N
                                                                            S                 S                              A
                                                                                      IC                                     G
                                                                                                                             E
                                                                                  Packaging       Advanced Package           R
                                                                                                      Designer

6                                                                                                   CADENCE DESIGN SYSTEMS, INC.
®



SPECCTRAQuest products today



                         PCB Systems           IC-Packaging
                             Model Management Environment

Power Integrity (PI)    SPECCTRAQuest
                         Power Integrity

                        SPECCTRAQuest  SPECCTRAQuest
                           SI Expert  IC Packaging (SQIC)
Signal Integrity (SI)
                                  SPECCTRAQuest
                                   Signal Explorer

                                     An environment for
                           creation, verification and management
                                    of all types of models


7                                                         CADENCE DESIGN SYSTEMS, INC.
®




                                                                        IC            Board
Introducing the Design Flow

• High speed design issues must be managed throughout the PCB
  design process



                        Model          Pre-Route                     Post Route
    Simulation       Development      Sol’n-Space                     Analysis
                     & Verification     Analysis                     Verification

                                             Topology      Constraint
            Layout                            Entry &       Driven
                                           Floorplanning    Layout




8                                                               CADENCE DESIGN SYSTEMS, INC.
®




                                                                         IC              Board

    SPECCTRAQuest in the PCB Design flow

                                                                  Physical Layout
                                                                  Physical Layout
                Exploration
                Exploration      Design/Implementation
                                 Design/Implementation   FP
                                                         FP
                                                                  Place
                                                                  Place     Route
                                                                            Route
                               Simulation
                               Simulation                     Verification
                                                              Verification

     Design Specs


                    SQ-SigXP
                    SQ-SigXP      Concept HDL Expert
                                  Concept HDL Expert     SQ
                                                         SQ      Allegro Expert
                                                                 Allegro Expert
                      CM
                      CM                    CM
                                            CM           CM
                                                         CM             CM
                                                                        CM
       I/O
      models                                      SPECCTRAQuest
                                                  SPECCTRAQuest
                                                         CM
                                                         CM
       • Model Verification                          SPECCTRA
       • Topology explorations
       • Rules development                   • Timing driven floorplanning
                                             • Post placement verification
9                                            • Post route verification
                                                                   CADENCE DESIGN SYSTEMS, INC.
®




     Constraint Driven Layout
                      • Design rule violations during
                        interactive routing are identified
                        in real-time
                      • Autorouter follows design rules -
                        powerful integration with
                        SPECCTRA!
                      • Because solution space analysis
                        has defined a set of conditions
                        under which the nets are known
                        to work, chance of first-pass
                        success is high.
                          – Nets can be ripped up and
                            rerouted, as long as they still
                            adhere to the design rules


10                                    CADENCE DESIGN SYSTEMS, INC.
®


         PSD 14.0 Constraint Manager




     • Common, powerful environment for constraint entry / editing / management
       and verification
     • Single mechanism for managing constraints throughout the design process

11                                                            CADENCE DESIGN SYSTEMS, INC.
®




Constraint Manager – Key Features


                         • Spreadsheet-based graphical
                           interface
                             – No cryptic formats or
                               cumbersome updating
                         • Provides unsurpassed Integration
                           across the entire design flow
                             – Consistent Front to Back solution
                             – No translations with static
                               constraint data
                             – Directly integrated with
                               schematic and PCB databases
                             – Analysis engines can update
                               spreadsheet data interactively

12                                            CADENCE DESIGN SYSTEMS, INC.
®




SPECCTRAQuest Power Integrity
  • Innovative technology developed and proven by Sun
    Microsystems, now commercialized by Cadence Design
    Systems, Inc. to address Power Delivery issues in high-speed
    PCB System Designs.

  • A design tool / methodology used to design and optimize the
    frequency-dependent characteristics of Power Delivery
    Systems in high-speed system designs

  • An integrated solution to allow many quick iterations of
    “change-simulate-analyze”

  • Introduced in PSD 14.1 release

                                                        CADENCE DESIGN SYSTEMS, INC.
®




  Power Delivery Requirements Trend
         Year   Voltage    Power    Current Frequency Ztarget
                (Volts)   (Watts)   (Amps)    (MHz) (m-Ohms)
         1990      5         5         1        16     250
         1993     3.3        10        3        66      54
         1996     2.5        30        12      200      10
         1999     1.8        90        50      600     1.8
         2002     1.2       180       150      1200    0.4

• Power dissipation and longer battery life fueling decreasing chip
  power supply voltages
  – Maximum allowable supply ripple decreases accordingly
• SoC, SiP fueling trend towards devices with large number of
  devices
  – The instantaneous switching current required is enormous
• The maximum acceptable power supply ripple voltage determines
  the target impedance which must be maintained across the PCB

                                                                CADENCE DESIGN SYSTEMS, INC.
®




Power Delivery System Design Challenges
     • Power supply droop
       – Alters system timing and can cause Setup failures
       – Can cause sampling errors that results in a system crash


     • Unreliable power delivery system design can cause increased
       common-mode EMI preventing product shipment due to
       compliance problems


     • Power delivery system impedance is frequency-dependent
       – Must be controlled for all frequency range of all transient currents

                                          Increases Development Costs and
                                           Increases Development Costs and
                                          Time to Market is LOST!
                                           Time to Market is LOST!
15                                                               CADENCE DESIGN SYSTEMS, INC.
®




 Power Delivery System Design -
 How it is done today

     • Standalone analysis tools
       – Design data translation is left up to the user
       – Changes to the design resulting from simulation is manual
     • Use Time Domain simulation
       – Power delivery system impedance is frequency-dependent!
       – With only time domain simulation, it is like searching for needle in a
         haystack
     • Over design - add more de-coupling capacitors than necessary
       – Expensive solution that may not work




16                                                                CADENCE DESIGN SYSTEMS, INC.
®




The Cadence approach

 • Allow users to determine the needs of the power delivery system
     – Target impedance
     – Decoupling capacitor requirements


 • Provide frequency domain analysis to find problem areas


 • Provide an integrated PCB design editor to optimize capacitor
   placement

                                   Develop reliable power delivery system
                                   Develop reliable power delivery system
                                   while shortening design cycle time
                                   while shortening design cycle time


17                                                        CADENCE DESIGN SYSTEMS, INC.
Introducing …                                                                              ®




SPECCTRAQuest Model Integrity
(in v14.2)

                          PCB Systems          IC-Packaging

Power Integrity (PI)    SPECCTRAQuest
                         Power Integrity

                        SPECCTRAQuest  SPECCTRAQuest
                           SI Expert  IC Packaging (SQIC)
Signal Integrity (SI)
                                  SPECCTRAQuest
                                   Signal Explorer

Model Integrity (MI)              SPECCTRAQuest
    (in v14.2)                       Model Integrity for
                                     An environment
                           creation, verification and management
                                   of all types of models


18                                                          CADENCE DESIGN SYSTEMS, INC.
®




SQ Model Integrity
• Family of products that offers model creation, manipulation and
  verification environment
     – First release (PSD release 14.2) will offer the basic creation/editing and
       sanity check environment for IO buffer models for following formats
        – Cadence (DML)
        – Quad [translator only]
        – IBIS 3.2 [.ibs, .pkg, .ebd files]
     – Future releases will offer advanced options that will provide verification
       environment and handle different kinds of models
        – Capacitor models for use with SPECCTRAQuest Power Integrity
        – S-Parameters
        – IC Package models
        – Connector/FPGA models
        – Link with PCB Librarian Expert series

19                                                                  CADENCE DESIGN SYSTEMS, INC.
®




SPECCTRAQuest Model Integrity




20                              CADENCE DESIGN SYSTEMS, INC.
®




Demonstration Overview
 • Model development and validation using SPECCTRAQuest Model
   Integrity

 • Constraint Development using SPECCTRAQuest SigXP


 • Topology development using SPECCTRAQuest Floorplanner


 • Constraints verification throughout the process


 • System level verification using Design Link capability


 • Power Integrity

21                                                          CADENCE DESIGN SYSTEMS, INC.
®




Brief Description - SPECCTRAQuest 14.2

• SQ/Allegro, SQIC/APD UI Synchronization
 Allow users to switch between SQ & Allegro and SQIC & APD plus
 following commands to be changed in SQ
     – Display > Element to replace Info > Item
     – Logic > Net Schedule to replace Topology > Edit Pin Order
     – Place > Manually to replace Floorplan > Component Place




23                                                                 CADENCE DESIGN SYSTEMS, INC.
®




Brief Description –
SPECCTRAQuest SI Expert 14.2

• Custom measurements
 Custom measurements and Custom Stimulus will be available when
 simulating from the board level through the CM. In prior releases they
 were only available from SigXP


• Differential Signalling improvements
 Extraction and simulation of coupled differential pairs in SQ, SigXP




24                                                       CADENCE DESIGN SYSTEMS, INC.
®




Brief Description - Constraint Manager 14.2

• Concept Database Synchronization
 Synchronizes constraints stored as Schematic properties and
 CM worksheets
• Custom Measurement
 Provides SigXP’s custom measurement capability in CM.
 Ability to store custom measurements and to display
 measurement results in CM [requires SQ SI Expert]

• Cross Probing Improvements
 Cross probing with Allegro to handle segments/ratsnest, pin
 pairs, DRCs and Clines


25                                                      CADENCE DESIGN SYSTEMS, INC.

High speed-pcb-board-design-and-analysis

  • 1.
    High Speed PCBDesign and Analysis
  • 2.
    ® Agenda • Today’s HighSpeed PCB design challenges • Cadence PCB solution overview • Demonstration overview • Summary • Q&A 2 CADENCE DESIGN SYSTEMS, INC.
  • 3.
    ® MARKET CONVERGENCE IS DRIVINGDESIGN CONVERGENCE MARKET CONVERGENCE DESIGN CONVERGENCE Communications Hardware Software Computing Multimedia Digital Analog IC Board Consumer 3 CADENCE DESIGN SYSTEMS, INC.
  • 4.
    ® High Speed Design Challenges IC Board 1 • System timing Clock 4 Driver Setup Hold 2 Tco D0 3 Flight Time D0 – What is the maximum data rate for reliable data transfer? • Waveform integrity D1 D1 D2 D2 Driving Receiving D0 D1 D2 – Do signals meet applicable electrical requirements? • Crosstalk – Do the signals interfere with each other? • Power and/or ground plane stability – Are power voltages at the ICs sufficiently controlled? • EMI (differential and common mode) – Are critical signals radiating too much energy? – Are power planes producing common-mode radiation? 4 CADENCE DESIGN SYSTEMS, INC.
  • 5.
    ® PCB System DesignFlow and Products Communications Functional Functional NC Sim Verification Verification PSpice/AWB Computing SPECCTRAQuest C Multimedia Exploration PCB Design Infrastructure O C Design Entry S Capture CIS N O I Concept HDL S N T Floorplanning R S A A SPECCTRAQuest T N I Consumer R A N A High-Speed L Allegro T I PCB Layout Y SPECCTRA M IC Board N S A Digital Analog T I SPECCTRAQuest N S S A IC G E Packaging Advanced Package R Designer 5 CADENCE DESIGN SYSTEMS, INC.
  • 6.
    ® IC Board PCB System Design Flow and Products Communications Functional Functional NC Sim Verification Verification PSpice/AWB Computing SPECCTRAQuest C Multimedia Exploration PCB Design Infrastructure O C Design Entry S Capture CIS N O I Concept HDL S N T Floorplanning R S A A SPECCTRAQuest T N I Consumer R A N A High-Speed L Allegro T I PCB Layout Y SPECCTRA M IC Board N S A Digital Analog T I SPECCTRAQuest N S S A IC G E Packaging Advanced Package R Designer 6 CADENCE DESIGN SYSTEMS, INC.
  • 7.
    ® SPECCTRAQuest products today PCB Systems IC-Packaging Model Management Environment Power Integrity (PI) SPECCTRAQuest Power Integrity SPECCTRAQuest SPECCTRAQuest SI Expert IC Packaging (SQIC) Signal Integrity (SI) SPECCTRAQuest Signal Explorer An environment for creation, verification and management of all types of models 7 CADENCE DESIGN SYSTEMS, INC.
  • 8.
    ® IC Board Introducing the Design Flow • High speed design issues must be managed throughout the PCB design process Model Pre-Route Post Route Simulation Development Sol’n-Space Analysis & Verification Analysis Verification Topology Constraint Layout Entry & Driven Floorplanning Layout 8 CADENCE DESIGN SYSTEMS, INC.
  • 9.
    ® IC Board SPECCTRAQuest in the PCB Design flow Physical Layout Physical Layout Exploration Exploration Design/Implementation Design/Implementation FP FP Place Place Route Route Simulation Simulation Verification Verification Design Specs SQ-SigXP SQ-SigXP Concept HDL Expert Concept HDL Expert SQ SQ Allegro Expert Allegro Expert CM CM CM CM CM CM CM CM I/O models SPECCTRAQuest SPECCTRAQuest CM CM • Model Verification SPECCTRA • Topology explorations • Rules development • Timing driven floorplanning • Post placement verification 9 • Post route verification CADENCE DESIGN SYSTEMS, INC.
  • 10.
    ® Constraint Driven Layout • Design rule violations during interactive routing are identified in real-time • Autorouter follows design rules - powerful integration with SPECCTRA! • Because solution space analysis has defined a set of conditions under which the nets are known to work, chance of first-pass success is high. – Nets can be ripped up and rerouted, as long as they still adhere to the design rules 10 CADENCE DESIGN SYSTEMS, INC.
  • 11.
    ® PSD 14.0 Constraint Manager • Common, powerful environment for constraint entry / editing / management and verification • Single mechanism for managing constraints throughout the design process 11 CADENCE DESIGN SYSTEMS, INC.
  • 12.
    ® Constraint Manager –Key Features • Spreadsheet-based graphical interface – No cryptic formats or cumbersome updating • Provides unsurpassed Integration across the entire design flow – Consistent Front to Back solution – No translations with static constraint data – Directly integrated with schematic and PCB databases – Analysis engines can update spreadsheet data interactively 12 CADENCE DESIGN SYSTEMS, INC.
  • 13.
    ® SPECCTRAQuest Power Integrity • Innovative technology developed and proven by Sun Microsystems, now commercialized by Cadence Design Systems, Inc. to address Power Delivery issues in high-speed PCB System Designs. • A design tool / methodology used to design and optimize the frequency-dependent characteristics of Power Delivery Systems in high-speed system designs • An integrated solution to allow many quick iterations of “change-simulate-analyze” • Introduced in PSD 14.1 release CADENCE DESIGN SYSTEMS, INC.
  • 14.
    ® PowerDelivery Requirements Trend Year Voltage Power Current Frequency Ztarget (Volts) (Watts) (Amps) (MHz) (m-Ohms) 1990 5 5 1 16 250 1993 3.3 10 3 66 54 1996 2.5 30 12 200 10 1999 1.8 90 50 600 1.8 2002 1.2 180 150 1200 0.4 • Power dissipation and longer battery life fueling decreasing chip power supply voltages – Maximum allowable supply ripple decreases accordingly • SoC, SiP fueling trend towards devices with large number of devices – The instantaneous switching current required is enormous • The maximum acceptable power supply ripple voltage determines the target impedance which must be maintained across the PCB CADENCE DESIGN SYSTEMS, INC.
  • 15.
    ® Power Delivery SystemDesign Challenges • Power supply droop – Alters system timing and can cause Setup failures – Can cause sampling errors that results in a system crash • Unreliable power delivery system design can cause increased common-mode EMI preventing product shipment due to compliance problems • Power delivery system impedance is frequency-dependent – Must be controlled for all frequency range of all transient currents Increases Development Costs and Increases Development Costs and Time to Market is LOST! Time to Market is LOST! 15 CADENCE DESIGN SYSTEMS, INC.
  • 16.
    ® Power DeliverySystem Design - How it is done today • Standalone analysis tools – Design data translation is left up to the user – Changes to the design resulting from simulation is manual • Use Time Domain simulation – Power delivery system impedance is frequency-dependent! – With only time domain simulation, it is like searching for needle in a haystack • Over design - add more de-coupling capacitors than necessary – Expensive solution that may not work 16 CADENCE DESIGN SYSTEMS, INC.
  • 17.
    ® The Cadence approach • Allow users to determine the needs of the power delivery system – Target impedance – Decoupling capacitor requirements • Provide frequency domain analysis to find problem areas • Provide an integrated PCB design editor to optimize capacitor placement Develop reliable power delivery system Develop reliable power delivery system while shortening design cycle time while shortening design cycle time 17 CADENCE DESIGN SYSTEMS, INC.
  • 18.
    Introducing … ® SPECCTRAQuest Model Integrity (in v14.2) PCB Systems IC-Packaging Power Integrity (PI) SPECCTRAQuest Power Integrity SPECCTRAQuest SPECCTRAQuest SI Expert IC Packaging (SQIC) Signal Integrity (SI) SPECCTRAQuest Signal Explorer Model Integrity (MI) SPECCTRAQuest (in v14.2) Model Integrity for An environment creation, verification and management of all types of models 18 CADENCE DESIGN SYSTEMS, INC.
  • 19.
    ® SQ Model Integrity •Family of products that offers model creation, manipulation and verification environment – First release (PSD release 14.2) will offer the basic creation/editing and sanity check environment for IO buffer models for following formats – Cadence (DML) – Quad [translator only] – IBIS 3.2 [.ibs, .pkg, .ebd files] – Future releases will offer advanced options that will provide verification environment and handle different kinds of models – Capacitor models for use with SPECCTRAQuest Power Integrity – S-Parameters – IC Package models – Connector/FPGA models – Link with PCB Librarian Expert series 19 CADENCE DESIGN SYSTEMS, INC.
  • 20.
    ® SPECCTRAQuest Model Integrity 20 CADENCE DESIGN SYSTEMS, INC.
  • 21.
    ® Demonstration Overview •Model development and validation using SPECCTRAQuest Model Integrity • Constraint Development using SPECCTRAQuest SigXP • Topology development using SPECCTRAQuest Floorplanner • Constraints verification throughout the process • System level verification using Design Link capability • Power Integrity 21 CADENCE DESIGN SYSTEMS, INC.
  • 23.
    ® Brief Description -SPECCTRAQuest 14.2 • SQ/Allegro, SQIC/APD UI Synchronization Allow users to switch between SQ & Allegro and SQIC & APD plus following commands to be changed in SQ – Display > Element to replace Info > Item – Logic > Net Schedule to replace Topology > Edit Pin Order – Place > Manually to replace Floorplan > Component Place 23 CADENCE DESIGN SYSTEMS, INC.
  • 24.
    ® Brief Description – SPECCTRAQuestSI Expert 14.2 • Custom measurements Custom measurements and Custom Stimulus will be available when simulating from the board level through the CM. In prior releases they were only available from SigXP • Differential Signalling improvements Extraction and simulation of coupled differential pairs in SQ, SigXP 24 CADENCE DESIGN SYSTEMS, INC.
  • 25.
    ® Brief Description -Constraint Manager 14.2 • Concept Database Synchronization Synchronizes constraints stored as Schematic properties and CM worksheets • Custom Measurement Provides SigXP’s custom measurement capability in CM. Ability to store custom measurements and to display measurement results in CM [requires SQ SI Expert] • Cross Probing Improvements Cross probing with Allegro to handle segments/ratsnest, pin pairs, DRCs and Clines 25 CADENCE DESIGN SYSTEMS, INC.

Editor's Notes

  • #13 Spreadsheet style allow you to sort, manipulate your design netlist to easy managing both electrical and physical constraints
  • #14 SPECCTRAQuest Power Integrity module is a new add on option to SPECCTRAQuest SI Expert. It embeds proven technology from Sun Microsystems, Inc along with design and analysis environment from Cadence to address power delivery issues in high-speed PCB systems design. SPECCTRAQuest Power Integrity embodies a methodology used to design and optimize frequency dependent characteristics of power delivery systems in high speed systems design. It offers an integrated design and analysis environment to allow users many quick iterations of “change-simulate-analyze” in a short period of time.
  • #15 Over the past decade, power delivery requirements for modern high-speed systems have been increasing rapidly even as the supply voltages have been dropping from 5V in early 1990s to less than 2V in systems being designed today. Chart above shows how the current requirements have grown 5 times faster than the voltages have dropped on most high-speed systems with microprocessors and complex bus architectures. This has resulted in complex high-speed microprocessor based designs requiring over 100 watts of power to be delivered to it. As the supply voltage has dropped in these systems, the tolerance ripple voltage has shrunk as well. 5% allowed ripple in a 5V system meant that the supply voltage could tolerate a swing of 0.25V. The same 5% ripple in a 1.8V system means the swing cannot be more than 0.09V! The systems are becoming more sensitive as the supply voltage drops. The need to reduce the supply voltage will continue to be driven by the battery life and thermal concerns. Most high-speed systems that have front end or post layout SI/Crosstalk simulations performed assume a clean dependable supply voltage. The approach was to sprinke more capacitors than needed to avoid hot spots. Any that were missed were caught in a prototype debug stage. This approach drives up the system per unit cost and complexity (harder to place and route when real-esate is tight).
  • #16 Power Delivery System design errors show up in various places. Unreliable power delivery (supply droop) can cause timing failures, which can result in system crashes. Improperly addressed hot spots in a high-speed system can increase common mode EMI preventing the product from shipping. Not solving the problem or addressing it too late in the cycle increases development costs and causes the product to miss its time to market window of opportunity, which can be fatal for many products in a competitive market place.
  • #17 How do people deal with these issues today? Most people tend to deal with it either by over-designing (a bypass cap per power supply pin per device) or by adding an iteration after the prototype debug shows problems. Both approaches are becoming unacceptable if the system cost or real-estate is an issue. Certainly adding an iteration to build a prototype eats into the precious time to market window for most companies building complex high-speed PCB systems. Some companies that use simulation for power delivery system design use standalone time domain (TD) simulation engines to find the voltage swing. The problem is that the cause of the swing is not identified by the TD simulation. Leaving the user to guess at the cause, make a fix and then run simulation again to see if the problem is solved or not. This is the “shooting in the dark” approach. There is no gurantee of convergence. There is a better approach……….
  • #18 The approach that Cadence has taken is a better approach. It investigates the problem in the frequency domain to identify the cause and also to suggest a solution that can fix the problem. The approach is rooted in the fact that power delivery system’s impedance is freuency dependent and must be controlled for all frequency ranges from DC to daylight. In addition to simulating in frequency domain to identify the problem and suggest a solution, SPECCTRAQuest Power Integrity offers an environment that makes multiple iterations of “change-simulate-analyze” very quick and easy. It offers an intergated design and analysis environment allowing the users to focus on the problem instead of struggling with data translation issues between the CAD system and the analysis engines.