Texas Instruments PSpice User Manual

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Getting started with the new PSpice® for TI

design and simulation tool

Ian Williams APP – LP – LDO

About me – Ian Williams

Business lead, Low-Voltage LDOs

• Career

– BSEE University of Texas at Dallas, 2009 – TI since 2009, LDO since July 2020

• Expertise

– 11 years working with various types of amplifiers – Co-creator of GWL amplifier SPICE model architecture – Co-creator of TI Precision Labs – Op Amps

• Fun fact

– Big music guy – have performed at festivals, DJ’d at

clubs and on FM radio, and even met my wife at Coachella 2013

Agenda

• TI simulation tools overview – 10 min.

• PSpice® for TI deep dive – 10 min.

– Features and limitations

– Built-in model library

• Setup and simulation examples – 25 min.

– Operational amplifier: OPA211 – Power supply: TPS7A52 – Modeling Application: Power MOSFET

• Additional resources

Please ask your questions

in the chat!

Part 1

TI simulation tools overview

Tip: SPICE stands for “Simulation Program

with Integrated Circuit Emphasis”

Time for some audience participation…

Introducing PSpice® for TI

PSpice for TI will help engineers speed time to market and reduce development costs, delivering:

• Full-featured simulation of entire systems.

– Advanced capabilities, including Monte Carlo and

worst-case analysis.

– Synchronized library of >5,700 models and counting. – No design size limitations. – Easy transition to layout and prototype.

• Integrated design resources.

– Quick access to TI product information. – No need to manually upload new TI models.

Why is TI partnering with Cadence?

Short design timelines

Today’s design engineers must

produce accurate designs on tight

deadlines — in many cases,

reducing the prototyping and evaluation phases of their designs.

Growing demand

There is an increased need for simulation software to test new

design concepts, accelerate product

development and demonstrate regulatory compliance.

Source: ABI Research

“Tools that are intuitive and include system-level simulation capabilities can

cut the development time and speed time to market.” – Kevin Anderson, Omdia

Desire for more advanced simulation

Existing simulation tools in the

market lack advanced analysis capabilities, model portability and flexibility, and easy library synchronization.

Is PSpice for TI replacing other TI tools?

Fundamentals

& skill-building

• Educational e-books

• Technical articles

• TI Precision Labs

• Power Supply

Design Seminars

(PSDS)

• Additional videos at

training.ti.com

Investigation &

brainstorming

• Easy part selection on TI.com

• Reference designs

for specific applications

• Application notes and technical white papers

Design &

simulation

• Evaluation modules

• WEBENCH® Power

Designer

• Filter Design Tool

• Analog Engineer’s

Calculator, Circuit Cookbooks & Pocket Reference

• TINA-TI™

Design

support

• e2e.ti.com

• Forums for expert

answers to technical

questions

PSpice for TI vs. TINA-TI

Analysis / simulation

AC, Noise, BIAS point, DC sweep,

Transient, Fourier

Variable sweeps

Monte Carlo analysis

Worst case analysis

Libraries / components

Internal libraries

Automatic library updates

in modeling application

Schematics

Create hierarchical schematic

Multipage schematics

PSpice for TI TINA-TI

Yes Yes

Built-

Temperature,

component,

parametric

Yes No Yes No

~5700 ~1300

Yes No Yes No

Temperature,

component

Part 2

PSpice for TI deep dive

Tip: PSpice for TI runs offline!

Software features and limitations FAQ

Q. Does PSpice for TI work offline?

A. Yes, an internet connection is not required to run.

Q. Is there a maximum number of nodes?

A. No, there are no design size limitations. You can also use multi-page schematics and

hierarchical blocks.

Q. Are there any other limits to be aware of?

A. Yes. The tool is designed primarily as a SPICE simulation environment for use with the built-in TI

models. If third-party models are imported, then only three nodes can be probed simultaneously.

Built-in TI model library

Matches the product tree on TI.com

Includes device-specific test benches

To accelerate your development

How do I update the TI model library?

• Updates to the model library are automatically detected and performed at

software startup.

– The user can choose not to update.

• The model library is installed locally on the user’s hard drive. Models can be

copied and imported into other tools

if desired.

– Location: C:\SPB_Data\cdssetup\pspTILibDir

Are models editable?

• Models are text files and may be edited with a text editor (I recommend

Notepad++) from the library directory

– Note: editing TI models breaks their signature, causing the tool to treat them as 3rd-party

• Some models have user-

editable parameters. Editing these does not break signature.

• If you edit a model and save it

in the same location, it will get over-written during the next library update.

Model file example

Modeling application

• Used to add customizable, parameterized components to your design:

– Power MOSFETs – Power diodes – Passives with parasitics – Independent sources – Switches

– Transformers

• Click Place  PSpice Component…

 Modeling Application in the top menu bar

• Note: these components do not

trigger the probe limit

Modeling application, cont.

• A simple UI opens for each type of component with editable fields

• Customize each parameter to your liking, then click Place to drop in schematic

– Note: Device parameters can still be edited from their properties once in the schematic

Power MOSFET window Power NMOS in schematic

Additional included model libraries

Description

Analog behavioral models for various math functions

Passives, dependent sources, switches, transmission lines

Customizable versions of many device types

Digital timing control, pull

Logic gates, flip

Independent voltage and current sources

Parameters, simulation control, library management, utilities

• These standard PSpice libraries are also included:

Library

ABM

ANALOG

BREAKOUT

DIG_MISC

-up / pull-down resistors

DIG_PRIM

-flops

SOURCE

• Note: components from these libraries do not trigger the probe limit

SPECIAL

Importing third-party or custom models

• With your project (.opj) selected, click Tools  Generate Part

• Browse to your model file in the new window, make your selections, and click OK

• The new model appears in your project’s library

Types of models on TI.com

Description

Analog / mixed in a way to be easy to import and use in PSpice / Cadence / OrCAD.

Analog / mixed in a way to be easy to import and use in TINA

Analog / mixed

simulators. HSPICE is

a branch of SPICE similar to PSpice, but models are not directly compatible.

Switch

I/O Buffer Information Specification model, typically used for digital pin timing analysis. Compatible with a broad range of industry simulators.

Type

-signal model for use in PSpice-based simulators. Packaged

PSpice

TINA-TI

-signal model for use in PSpice-based simulators. Packaged

HSPICE

(uncommon)

SIMPLIS

IBIS

-mode power supply model for use in SIMPLIS.

-signal model for use in HSPICE-based

-TI.

Part 3

Setup and simulation examples

Tip: Enabling AutoConverge in your sim

profile can fix a broad range of

convergence issues.

Operational amplifier example – OPA211

Schematic capture

AC simulation result

Power supply example – TPS7A52

Schematic capture

Transient simulation result

Modeling Application – Power MOSFET

Schematic capture

DC simulation result

Part 4

Additional Resources

Tip: Choose the “Last Plot” setting in your

sim profile to preserve results display

settings between runs.

Additional resources

Hands-on training manual

• Self-guided, step-by-step tutorial that walks the user through the entire tool workflow

• Includes basic and more advanced content

• Includes debugging and troubleshooting

• Available from the PSpice for TI start page:

• Click Training Course

Additional resources, cont.

Overview content

How to simulate complex analog power and signalchain circuits with PSpice® for TI

[Link]

PSpice for TI

overview video

[Link]

Technical training videos

[Link to videos]

TI.com/pspice-for-ti

“Trust, but verify” SPICE models

• Series of articles that covers verifying parameters of amplifier models:

– Part 1: Output impedance – Part 2: Small-signal bandwidth – Part 3: Input-referred errors – Part 4: Noise

Direct support from TI

• For tool-related support: Simulation, hardware & system design tools forum

• For specific model or product support: post to that product’s forum

– i.e. For amplifier support, post to the Amplifiers forum

Note: these forums are all supported by TI applications engineers who are

graded on responsiveness and quality of support. You should get an initial reply in 24h.

SPICE tips – analysis parameters

Effect

Relaxes multiple parameters if needed to enable convergence

Sets the absolute

nodal currents between DC

iterations

Sets the relative tolerance of the nodal voltages

iteration compared to the first

Adds every p

Adds capacitance from every node to ground

Option Default Relaxed

AutoConverge Off On

ABSTOL 1e-12 1e-10

RELTOL 1e-3 3e-3

GMIN 1e-12 1e-10

CSHUNT 0 1e-15

tolerance of

at each DC

conductance parallel to

-n junction

SPICE tips – DC path to GND

MID MID

IN-_ESD+

IN+_ESD+

IN+_ESD-

IN-_ESD-

R34 250

R35 250

R52 1G

R53 1G

C_CM+ 4e-12

C_CM- 4e-12

C_DIFF 4e-12

IN+

IN-

• Ensure DC path to ground at every node

– Can force a path with large resistors (1T, etc.) that don’t affect electrical performance – Try to use the smallest value possible

MID

SW_OL

OL_SENSE

COM

SW+OLN

OLP

OL_SENSE

R31 1

R32 100

C12 10e-12

OLN

OLP

OL_SENSE

SPICE tips – linear circuits

• Design functional blocks with as linear behavior as possible

– Sharp transitions or discontinuities cause issues with convergence checks – Use R-C filter networks to reduce bandwidth of subcircuits for smooth transitions – Use voltage inputs and current outputs wherever possible

Voltage inputs Current output

R-C filter slows edges of subcircuit output

Resistor converts current to voltage and provides DC path to GND

SPICE tips – bounded matrix

MID

VCCS_LIM

VC+

VC- IOUT+

IOUT-

VCCS_LIM_1

R44 1e6

Out

• Keep matrix equations as tightly bounded as possible

– Place limits on gain and buffer stages – Use only as much gain as required – Scale resistances to keep node voltages and currents in similar ranges

SPICE tips – simplified components

V_B

-+-

VCVS 2 1

V_B+ 5

VCVS1 1

V_B- 5

V_AV_B- V_B+

D1 D2

V_B

-+-

VCVS 2 1

V_B+ 5

VCVS1 1

V_B- 5

V_AV_B- V_B+

SW- 0

SW+ 0

• Replace complex components with simple approximations if exact component modeling isn’t necessary

– Example: ideal diode  voltage-controlled switch

Diode equation:

Thank you!

SLYP725

IMPORTANT NOTICE AND DISCLAIMER

TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS.

These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources.

TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on

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warranties or warranty disclaimers for TI products.

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265

Texas Instruments PSpice User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual