LTpowerCAD II User Guide Datasheet by Analog Devices Inc.

L7Llnb TECHNOLOGY



LTpowerCAD

TM

IIv2.0DesignTool

User’sGuide



LTpowerCAD@analog.com



Ver.2.5.7

Jan2019

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Note:TheLinearTechnologyLTpowerCAD™IIDesignToolisapowerfulpowersupplydesignprogramforselected

LinearTechnologyproducts.ThisdocumentservesasaguidefortheLinearTechnologyLTpowerCAD™IIDesign

Tool.ItexplainsthevariousfunctionsthataresupportedbytheLTpowerCAD™II



DesignTool.

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2

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Linear Technology Corporation LTpowerCAD'”I |l Design Tool License Agreement Installation Requirements 4 Installing LTpowerCAD‘M ll 7 Start window & Features 10 Part Search window & Features 14 Design window & Features 21 Power Stage Design Tab & Features 23 Loss Estimate and Break Down Tab & Features 34 Loop Compensation and Load Transient Tab & Features 42 Linear Technology Corporation LTpowerCAD'”I |l Design Tool License Agreement 54 Load Transient Prediction 57 The Accuracy of LTpowerCAD'“ ll Design Tool 57 LTpowerCAD'”I |l Design Tool Supported LTC Products List 58 LTpowerCAD'”I |l Design Tool Contact Information 58 LTpowerCAD'”I |l Design Tool Release Information 58

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TABLEOFCONTENTS



Installation:

LinearTechnologyCorporationLTpowerCAD™IIDesignToolLicenseAgreement 3

InstallationRequirements4

InstallingLTpowerCAD™II7



ProgramWindows:

StartWindow&Features10

PartSearchWindow&Features14

DesignWindow&Features21

PowerStageDesignTab&Features23

ii.

LossEstimateandBreakDownTab&Features34

iii.

LoopCompensationandLoadTransientTab&Features  42

Appendix:

LinearTechnologyCorporationLTpowerCAD™IIDesignToolLicenseAgreement 54

LoadTransientPrediction57

TheAccuracyofLTpowerCAD™IIDesignTool57

LTpowerCAD™IIDesignToolSupportedLTCProductsList58

LTpowerCAD™IIDesignToolContactInformation58

LTpowerCAD™IIDesignToolReleaseInformation58

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LTQowerCAD’“ Design Tool License Agreement guideline, please visit www.|inear.com

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1.1

LINEARTECHNOLOGYCORPORATIONLTPOWERCAD™IIDESIGNTOOLLICENSE

AGREEMENT/DISCLAIMER



WelcometotheLinearTechnologyLTpowerCAD

™

IIDesignTool.TheLTpowerCAD™IIDesignToolisapower‐

fulpowersupplydesigntoolprogramthatsignificantlyeasesthetasksofselectingcomponentvalues,estimat‐

ingpowerlossandefficiency,andoptimizingthecompensationloop.



Thisdesigntooliscopyrighted.InaccordancewiththetermsandconditionsoftheLTpowerCAD™Design

ToolLicenseAgreementintheAppendix,uponacceptanceoftheagreement,youwillbegrantedanon‐

exclusive,non‐transferable,royalty‐freerightsolelytodesignsupplieswithLinearTechnologyproducts.Linear

TechnologyCorporationownstheLTpowerCAD™IIDesignTool.Youmaynotredistribute,adapt,translate,re‐

verseengineer,decompile,ordisassembletheLTpowerCAD™IIDesignTool.Upgrades,modifications,orre‐

pairstothisdesigntoolwillbestrictlyatthediscretionofLinearTechnology.



Asalways,LinearTechnologyhasmadethebestefforttosupportourcustomers.However,duetotheexternal

componentvaluevariations,itremainsthecustomer’sresponsibilitytoverifytheprogram'scalculationresults

byactuallybuildingthecircuitandevaluatingitsperformance.



Note:

PleasenotethatthecurrentversionoftheLTpowerCAD

™

IIDesignToolonlysupportsalimitednumberof

LinearTechnologyMonolithicanduModuleParts.ForafulllistofLinearTechnologyproductsandselection

guideline,pleasevisitwww.linear.comorcontactyourlocalsalesrepresentative.

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5

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1.2

INSTALLATIONREQUIREMENTS

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Microsoft .NET Framework

 LTpowerCAD II v2.0 uses components from Microsoft's .NET framework. Microsoft .NET Framework 3.5 SP1 or higher is

required to be installed on the system. This requirement, if not met, is automatically installed by the installer during the

installation process.

Microsoft SQL Server Compact

 LTpowerCAD II v2.0 also uses Microsoft's SQL Server Compact. Microsoft SQL Server Compact 3.5 SP2 os required to

be installed on the system. This requirements, if not met, is automatically installed by the installer during the installation

process.

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Where do I

et these?

The LTpowerCAD II v2.0 installer automatically detects if your system has these requirements installed during the installation

process. If the system does not meet the requirements the installer will ask and automatically download and install these

requirements. If for some reason your system has not installed these requirements which may be causing errors running the

program, these requirements are also available from the links below below.

Microsoft .NET Framework 3.5 SP1 (http://www.microsoft.com/en-us/download/details.aspx?id=22)

Microsoft SQL Server Compact 3.5 SP2 (http://www.microsoft.com/en-us/download/details.aspx?id=5783)

select Progenies. Security Users Full Control ﬂied nine: OW Hes WMTWCADZ

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Installation Folder Permissions

 LTpowerCAD II v2.0 requires proper configuration of permissions of its installation folder for proper operation. Folder

permissions are automatically configured by the installer during the installation process.

Where do I check this?

The LTpowerCAD II v2.0 installer automatically configures permission settings of the installation folder during the installation

process. To check the permissions of your installation folder for Windows, go to your installation folder location and right click to

select Properties. On the Security tab select the Users account to see the folder permissions. The folder permissions for the user

should be set automatically set to Allow Full Control. If for some reason these folder permissions are not set to Full Control, please

set these permissions manually as shown below.

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1.3

INSTALLINGLTPOWERCADII



Getttin

the LTpowerCAD II v2.0 Installer

LTpowerCAD II v2.0 is installed with the LTpowerCAD II v2.0 Installer. The install package can be downloaded directly from the

Linear Technology Website Design Tools Page http://www.linear.com/designtools/software/

To install LTpowerCAD II v2.0, double click the "setup.exe" file to open the Installer Application for the program located in the

install package.

Do not install by instead double clicking the "MS.msi" in the installer package as this will prevent the installer from installing any

missing required Microsoft program requirements.

Installation Steps

To Install LTpowerCAD v2.0 follow the steps in the installer. For a typical installation no information is needed by the user, just click

the Next button in the installer windows until the final window in the installer is reached, then click Close to complete.

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LTpowerCAD v2.0 Shortcuts

After the installation has completed, LTpowerCAD v2.0 places a shortcut to the program on your desktop as well as a shortcut in

your Windows Start Menu LTpowerCAD v2.0 program folder. Double click any of these shortcuts to open the program and get

started with your LTpowerCAD v2.0 design.



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2.1STARTWINDOW&FEATURES



The Start Window is the start-up window of the program. From the Start Window :

 Start a new Design

 Open an Existing saved design

 View Help File

 View LTC Sales Contacts

 View LTC Toolbox

 Sync Release to get the latest design tools and version program

Start NM Design LTC icon Excel icon Open Existing Design Halp LTC Sills Contact

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Start New Design :

Hit the Start New Design button to begin a new power supply design. Clicking this buton takes you to the Part Search Window

where you can enter the operating conditions for your application to find suitable parts to start designing with.

Open Existing Design :

Hit the Open Existing Design button to open a previosly saved design tool file. To open an existing LTpowerCAD II v2.0 design tool

click on the LTC icon. To open an existing LTpowerCAD v1.x Microsoft Excel based design tool click on the Excel icon.

Help :

Click the Help button to open the LTpowerCAD II help file.

LTC Sales Contacts :

Click the LTC Sales Contacts button to view contact for our Sales offices around the world. Phone, Fax and Sales office addresses

are available. Your local sales office is a great resource to help you get in touch with your local Field Sales Engineer as well

as your local Field Applications Engineer to help you with your power supply design needs.

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LTC Toolbox :

Click the LTC Toolbox button to open the LTC Toolbox which contains generic tools to help with calculations for your design. Sync

release function ensures you have the latest available tools and that they are all up to date.

Updating Releaselnfobtt Success LTpowevCAD Design Tool library was updated successful

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Sync Release :

Click the Sync Release button to update your LTpowerCAD II program with the latest design tools available as well as to get the

latest version of the LTpowerCAD II v2.0 program. Clicking the Sync Release button takes you to the program updater which

downloads all the latest tools to your installed library and also makes sure you always have the latest version of the program.



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2.2



PARTSEARCHWINDOW&FEATURES



The Part Search Window helps you to find the right part for your supply requirements based on

your operating conditions. Begin the design process with the part's available design tool. From the

Part Search Window :

 Enter input operating conditions, output rail requirements as well as select optional part features to

find qualifying parts in the library

 Search for even more parts using the LTC parametric search on the web

 View basic specs. and features for parts

 Open part datasheets

 Open design tool(s) for the part to begin the design process

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Enter Supply Basic Requirements :

Enter the basic power supply requirements for the application in the top half of the Part Search Window.

Converter Specification :

Supply input and output basic specifications are entered in this region.

Converter Topology : Select the required converter topology to filter the part search results (All, Buck, Boost, Buck-

Boost,...)

Converter Type : Select the preferred converter type to filter the part search results (All, Monolithic, uModule

Regulator, Controller,...)

Min., Nom. Max. Input Voltages : Enter the expected minimum, nominal and maximum input supply voltage for the

converter

Num. of Output Rails : Select the number of output rails required (One, Two, Three,...)

Output Rail : Enter the desired output voltage and current required of each output rail

Optional Features : Burst Mode ’ Synchronous FET Isolareo Run / Enable Sync. m Exrernal Cloek Output Voltage Tracking Remote Voltage Sensing Margm (omrol Power Good Moniror Poly-phase 1' Load Share : IZC/PMBus Interface

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Optional Features :

Select from a set of some common optional features available for LTC parts

Burst Mode : High Efficiency Light Load Current Operation

Synchronous FET : Synchronous power stage mosfet

Isolated : Isolated topology

Run/Enable : Run or enable pin available

Sync. to External Clock : Ability to synchronize switching frequency to an external clock signal

Output Voltage Tracking : Ability for output voltage to track an external reference signal

Remote Voltage Sensing : Ability to optionally remotely sense the output voltage for accurate output voltage

regulation at the point of load

Margin Control : Ability to margin output voltage based on margin pin configurations

Power Good Monitor : Power Good pin to signal if output voltage is outside of regulation window

Poly-phase / Load Share : Ability to parallel output rails to share load current among paralleled phases to scale up

current capability

I2C / PMBus Interface : I2C / PMBus compatible for power system communications & configuration

Find Part Num. (##1##) -

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Search for parts:

Search for parts within the LTpowerCAD II program library or if a part is not in the library, check the LTC Parametric search

tables on the web to find the best part to fit your needs.

Search Tools :

Search Button:

Search the LTpowerCAD II program library for a list of parts that qualify for your application requirements. The

search results are shown in the table in the lower half of the Part Search Window. If you know a specific part you

are looking a design tool for, after entering your Converter Specifications, you can look for that part directly by

entering the part number in the Find Part Num. search box.

All Parts :

View a list of all parts within the current LTpowerCAD II program library installed on your system

LTC Web Search :

The LTpowerCAD II program library is constantly growing, so not all parts available from LTC may be

included. However, you can do an extensive search using the parametric tables on Linear Technology's website

to search through all parts available from Linear Technology to see what other parts may fit your needs by

clicking the LTC Web Search Button. The LTpowerCAD II program will use your entered converter specification

values for the search.

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19

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Alwa

s Keep Search Pa

e Open :

The check box option allows for the search window to remain open (not automatically closed) after a part is

selected from the search table to open its design tool.

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LTpowerCAD Library Search Table :

Search results after clicking the Search button are displayed in the lower half of the Part Search Window. The search results

show a list of parts in the LTpowerCAD library on your system that qualify to meet or exceed your entered power supply design

requirements.

Search Results :

The Search Results in the Search Table show a list of qualifying parts including some basic information about each of the

qualifying parts. From the Search table results you can also click to open the datasheet of the part you may be interested to get

additional information. For a chosen part with available design tool(s), begin your power supply design by selecting the design tool

icon in the left column of the table to open the design tool for the part.

A brief Description of some of the Search Table column's are shown below.

Desi

n Tool :

For a given row / part, the column holds spaces for two buttons. The left button (LTC logo), if active, indicates

that an LTpowerCAD v2.0 design tool is available for the part. The right button (MS Excel logo), if

active, indicates that an LTpowerCAD v1.x Microsoft Excel based design tool button is available for the part.

Click on either of these buttons to open the design tool for the part and start your power supply design.

Website \ LKW-b LK Wl‘b LIL Wrb

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Website :

For a given row / part, the column holds an LTC Web button. Click the button to open the datasheet for the part

to get detailed information about the part.

Other Columns :

The search results table also has many other columns to show some basic information for the part.

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2.3DESIGNWINDOW&FEATURES

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The Design Window displays the design tool for the part. Within this window we can optimize the

components in the supply design to create a power supply design that satisfies all of the details of

your design requirements. Some key information to get you started is highlighted below. A detailed

description of the Design Window and its features is given in the following sections.

Tab Structure of the Design Window

The Design Window is arranged into tabs (shown below). Each of the tabs covers different aspects of the supply design. Each Tab

is described in more detail in the following sections.

Cells Within the Design Window

Within each of the tabs are blue cells which allow you to enter your chosen operating conditions and component values. There are

also yellow cells which show key part information, suggested component values and calculated parameters to help guide you

through finalizing the system components. The yellow cells if highlighted in red indicate warnings for the supply design, ie. a

parameter of the design is outside of the operating limits of the part, or the calculated parameter does not meet your

requirements. Blue cell entries may need to be adjusted to get rid of any warnings so the component design meets your

design requirements within the part's operating limits.

Other Controls Within the Design Window

The Design Window is also arranged with a few other controls, such as selection buttons, drop down lists and sliders for adjusting

various parameters of the design. More detail of these additional controls is available in the following sections.

Power Stage Design Tab :

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Loss Estimate & Break Down Tab :

Loop Comp. & Load Transient Tab :

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

POWERSTAGEDESIGNTAB

The Power Stage Design Tab offers a user friendly schematic interface for your power supply

design. It details important steady state aspects of your design such as output capacitor design for

output voltage ripple requirements, inductor design for inductor current ripple design, current

sensing network for current limit design. It also details all critical component values including

feedback network, power stage mosfet choice, and compensation network components used in the

design in a quick to review and easy to read schematic format. Other features of the Power Stage

Design Tab include :

 A printable, image capturable, zoomable interactive schematic with various controls to help you

select configurations, suggest component values and guide your design with value warnings and

information

 A side bar listing a summary of the basic operating conditions for your application such as input

voltages, switching frequency and input and and output voltages for each of the output rails of your

design

 Option to view design steps / design wizard

 Option to view an example layout image for your supply

 Option to export your project to LTSpice for time based simulations to see other performance

aspects of your design

A more detailed description of some of these features available on the Power Stage Design Tab are

shown below:

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Operating Conditions Summary :

A summary section is located on the left of the Power Stage Design Tab listing a basic summary of the operating conditions for the

application as well as information for the basic suggested maximum ratings for the part used in the design.

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Interactive Schematic Interface :

Schematic of your supply including critical components for the design, and tools to help you optimize these critical component

values. The schematic includes information for the different important groups of components in the schematic. Suggested values,

calculated parameters and warnings help you with proper component value choices.

Schematic Cells :

The schematic is arranged with different cells (textboxes) located in the region of components of the schematic which detail

component values and their related calculated parameters. The different types of cells are detailed below.

Blue cells :

Enter your chosen component values here

Yellow cells :

Show suggested component values and calculated design parameters to help guide you through the system's

component design.

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Red cells :

Indicate warnings for the supply design. For example, a parameter of the design is outside of the operating limits of

the part, outside of the suggested range, or is outside of the range which will meet your requirements. When the

cursor is placed over the red cell, a tooltip message becomes available to give you an idea of what the warning is

about. Blue cell entries may need to be re-adjusted to get rid of any warnings to guide you towards more appropriate

component value choices.

Schematic Buttons & Drop Down Lists :

The schematic is also arranged with other controls such as buttons and drop down lists to help select between different part

configuration options and select among discrete parameters available for the part

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Selection Buttons :

Click selection button to toggle between different configuration options for the part. For example, for parts that can be

configured for either DCR Current Sensing or Rsense Current Sensing options a button is available on the controller

package in the schematic image. For this example you can Click the Select Rsense Sensing button to elect an

Rsense current sensing configration is desired for the part. The selection then modifies the schematic to reflect your

configuration selection.

Example :

DCR Sensing Configuration Selected with Selection Button

Rsense Sensing Configuration Selected with Selection Button

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Drop Down Lists :

Choose a value from the drop down list to select between discrete parameter values available for the part. To use,

place cursor over the Drop Down List control to open the drop down list. Move the cursor over a value in the list and

click to make the selection of that value. For example, for parts that have an extenally programmable maximum

current sense voltage threshold (for current limit programming) the drop down list allows the user to select a value

from the discrete set of values that are available to be programmed for the part.

Example :

Programming Current Limit Threshold with Drop Down List

Schematic Zoomin

& Pannin

Located above the schematic there are buttons to allow for zooming in and out of the schematic as well as zoom fitting the

schematic to the screen. The schematic can also be panned while zooming in.

Zooming In / Out and Zoom Fit of the Schematic :

For any of the zoom button options, click once to take a zoom step in or out of the schematic. For Zoom Fit, click once

to return the schematic zoom level back to normal which fits the schematic to schematic area of the window.

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Panning on a zoomed in schematic:

To pan around on a zoomed in schematic, click and hold the left mouse button down to "grab" the schematic, a hand

icon will appear in place of your cursor. While holding the left mouse button down move the mouse to pan the

schematic in the opposite direction.

Schematic Printin

& Savin

an Ima

e of the Schematic:

Located above the schematic there are buttons to allow for printing the schematic to a printer as well as saving an image of the

schematic to a file for pasting to an external document (such as an email).

Printing to a printer :

Click the button with the printer icon to initiate printing of the schematic image to a printer. Clicking the Print

Schematic button opens the familiar Microsoft Windows print dialog window.

Capturing an image of the schematic :

Click the button with the camera icon to initiate saving of the schematic image to a file. Clicking the Save Schematic

Image button opens the familiar Microsoft Windows save file dialog window.

Other Power Stage Design Tab Options :

The Power Stage Design Tab also includes other useful features such as viewing basic power supply design steps, viewing an

example of a recommended layout for the supply as well as exporting the design for simulation in LTSpice.

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iewin

Power Suppl

Desi

n Steps :

Located above the schematic is a button to allow for viewing the basic recommended design steps to complete a power supply

design. Click to open.

View Design Steps :

iewin

a La

out Example :

Located above the schematic is a button to allow for viewing an example of a recommended layout for your supply. Click to open.

Within the layout example window there are also options to print the layout example image to a printer as well as saving an image

of the example layout to a file.

View Layout Example :

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Exportin

our power suppl

desi

n to LTSpice for Simulation :

The LTpowerCADTM II Design Tool offers users the ability to simulate their designed circuits with the LTSpiceTM simulator, which is

a real-time simulation software that can be downloaded freely at :

LTSpice TM (http://www.linear.com/designtools/software)

Located above the schematic is a button to allow for exporting your current power supply design to LTSpice for simulation. LTSpice

must be installed. Click the button to export your design. Clicking the button prompts you to first save the exported .asc file before it

is automatically opened in LTSpice.

Export to LTSpice :

LTC Toolbox :

Located above the schematic is a button to open the LTC Toolbox to use the generic design tools available there.

LTC Toolbox :

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Savin

/ Openin

LTpowerCAD v2.0 Pro

ect Files :

LTpowerCADTM II v2.0 Design Tool projects can be saved to file for later use.

Saving a design tool project can be done from the main menu bar in the Design Window. Click File --> Save As... to save your

project to a file. To open a saved file click File --> Open Project to choose a saved file. The extension for LTpowerCAD II v2.0

design tool projects is ".ltpc". These saved files are associated with the LTpowerCAD II v2.0 program and can be recognized as

shown below. Note, as mentioned in the Start Windows & Features section, these saved files can also be opened directly from the

Start Window. The saved files can also be opened by double clicking the saved file's icon.

LTpowerCAD II v2.0 saved design tool project :

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2.LOSSESTIMATE&BREAKDOWNTAB



The Loss Estimate & Break Down Tab offers estimations for power stage efficiency and power

losses to help you optimize your component and operating condition choices to maximize your

supply's efficiency and minimize heat due to power loss in your power stage components.

Estimations are made for each output rail of your design. Features of the Loss Estimate & Break

Down Tab include:

 Estimations organized by rail; each rail has its own separate tab

 Operating Conditions Summary

 Cell Structure

 Tab's Cell Types

 Efficiency & Power Loss Chart Cursors & adjustable Axes

 Switching and conduction losses in each of the power stage mosfets including synchronous fet body

diode loss

 Conduction losses in the power stage inductor and current sensing elements

 Controller LDO losses

 Optional External bias voltage entry

 Freezable Efficiency & Power Loss curve set for comparing power stage configurations and

operating conditions

 Power Loss Breakdown Chart

 Power mosfet thermal resistance entries to help estimate mosfet case temperature rise

 Inductor core loss entry (single value entry, core loss not yet estimated)

 Inductor & MOSFET Libraries where you can select from a built in library of mosfets, or add your

own favorite parts to the library

 Display of full load total Input Power, Output Power, Loss & Efficiency

A more detailed description of some of these features available on the Loss Estimate & Break

DownTab are shown below:

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Each Rail Has Its Own Tab :

Estimations are made for each rail separately, each rail has its own tab. To view estimations for a particular tab in your design,

select the tab for the output rail located on the left of the Loss Estimate & Breakdown Tab.

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Operating Conditions Summary :

A summary section is located in the top left corner of the Loss Estimate & Break Down Tab listing a basic summary of the

operating conditions for each output rail in your application.

Cell Structure :

The Loss Estimate & Break Down Tab is arranged with different cells (textboxes) which detail component values and their related

calculated parameters. The different types of cells are detailed below.

Tab's Cell Types :

Blue cells :

Enter your chosen component specifications here. For components chosen from the library, the component specs. will

be shown here.

Yellow cells :

Shows each component's loss and temperature rise estimations as well as total rail input power, output power, loss

and efficiency estimated at full load.

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Component Libraries :

The Loss Estimate & Break Down Tab is also arranged with a Select button within each group of components (ie Inductor

component group, Top Mosfet & Bottom Mosfet component groups). Click the Select button to open the component library

where you can choose a component from the built in component library, or add your own favorite component to your user library

stored on your system.

Power MOSFET Library :

The Power MOSFET Library Window is arranged in 2 sections.

 The top half of the window contains a table of built in parts. Critical mosfet specs are shown in the table for each part. To

select a component in the library for use click on the row of the component and click the Select button for the section.

 The bottom half of the window is for parts in your User Library which is stored in your system's installation folder.

o The top half of this section contains a table of parts that are available in your User Library. To select a component in

the libary for use click on the row of the component and click the Select button for the section.

o The bottom half of this section contains a row to enter information for a new part you would like to add to you User

Library. To add a part to you User Library enter information for the component in the cells provided, these specs. are

common specs. that can be found in the component's datasheet. Click the Add Part To Library button to submit

adding the part to the library.

 At the bottom of the window is the Vendor Links section which contains icons for various leading component manufacturers.

Click one of these icons to open up the vendor's component search web page.

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Power Inductor Library :

The Power Inductor Library Window is arranged in 2 sections.

 The top half of the window contains a table of built in parts. Critical inductor specs. are shown in the table for each part. To

select a component in the library for use click on the row of the component and click the Select button for the section.

 The bottom half of the window is for parts in your User Library which is stored in your system's installation folder.

o The top half of this section contains a table of parts that are available in your User Library. To select a component in

the libary for use click on the row of the component and click the Select button for the section.

o The bottom half of this section contains a row to enter information for a new part you would like to add to you User

Library. To add a part to you User Library enter information for the component in the cells provided, these specs. are

common specs. that can be found in the component's datasheet. Click the Add Part To Library button to submit

adding the part to the library.

 At the bottom of the window is the Vendor Links section which contains icons for various leading component manufacturers.

Click one of these icons to open up the vendor's component search web page.

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Efficiency & Power Loss Chart & Options :

The Efficiency & Power Loss Chart shows an estimation of efficiency and power loss at the operating conditions over the load

current range where inductor valley current is non-negative. The chart includes the option to freeze the curve for a particular

operating and configuration condition for comparisons.

Freezing the chart's estimation curves for comparison:

To freeze the chart's estimation curves click the Freeze Plot checkbox. While the checkbox is checked the estimation curves

remain frozen. Freezing the curves comes in handy for comparison to another set of operating conditions or another configuration

of your power stage component choice. To view the frozen curves against another condition, change the conditions (ie Vin) and

click Update Plots.The example below shows a comparison of the efficiency estimation at 12V & 4.5V input voltage.

Cursors:

Hover the mouse above the Efficiency & Power Loss plot. The values for the curve at the mouse position are displayed in the

Cursors group box.

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Set up Plot Axes Preferences:

To set up the Rail Total Efficiency & Power Loss vs. Load plot, double click on the chart to open the Setup Axes window shown

below. The window allows for adjusting min, max and interval step values for the 3 axes.

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

LOOPCOMPENSATION&LOADTRANSIENTTAB



The Loop Compensation & Load Transient Tab offers estimations for control loop, output

impedance & load transient to help you optimize your output capacitor, inductor & compensation

components to get the performance you need to meet your application requirements. Estimations

are made for each output rail of your design. Features of the Loop Compensation & Load Transient

Tab include:

 Estimations organized by rail; each rail has its own separate tab

 Sliding bars for adjusting component values with standard resistor & capacitor values

 Real time estimation allows you to see the trend of by increasing / decreasing component values

has on characteristics

 Suggested compensation and feedback network component values based on requirements

 Inductor & Output Capacitor Libraries

 Multiple plots available : Loop Gain, Feedback Network, Output Impedance, Control to Output,

Compensator plots

 Plot options : Plot cursors and markers for easy readability of data points and freezing of plots for

comparison against other component configurations & operating conditions

 Ability to export plot data to file (such as Microsoft Excel) and Import data from file for comparison to

other conditions or against bench test data

A more detailed description of some of these features available on the Loop Compensation & Load

Transient Tab are shown below:

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Each Rail Has Its Own Tab :

Estimations are made for each rail separately, each rail has its own tab. To view estimations for a particular tab in your design,

select the tab for the output rail located on the left of the Loop Compensation & Load Transient Tab.

Operating Conditions Summary :

A summary section is located in the top left corner of the Loop Compensation & Load Transient Tab listing a basic summary of the

operating conditions for each output rail in your application.

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Cell Structure :

The Loop Compensation & Load Transient Tab is arranged with different cells (textboxes) which detail component values and their

related calculated parameters. The different types of cells are detailed below.

Tab's Cell Types :

Blue cells :

Enter your chosen component values & design requirements here. For components chosen from the library, the

component specs. will be shown here.

Yellow cells :

Shows suggested component values as well as plot marker points and plot cursor data for easy readability of plot data

Component Libraries :

The Loop Gain & Load Transient Tab is also arranged with a Select button within each group of components (ie Inductor

component group, Bulk & Ceramic Output Capacitor groups). Click the Select button to open the component library where you

can choose a component from the built in component library, or add your own favorite component to your user library stored on

your system.

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