In several previous LTspice posts I described how to use the simulator as a test jig for single IC’s and gates. Each block in a circuit should be tested within LTspice before creating a multi-circuit simulation to verify performance against expected results. The test jig process included downloading a custom gate, IC, and spice code for the cd4066 bi-polar analogue switch from the yahoo LTspice user group, and the creation of my own 74LS193 pre-setable up/down counter from primitive logic gates. Ltspice is very flexible. Most discrete components are readily available in the library, with a great support group from on yahoo. There are a wide variety of spice and pspice models to important from many Internet sources as well..

The Circuit to Simulate

I came across this digital volume control circuit during a web search. The circuit seems to be fairly popular as it shows up in thousands of places on the web. I thought it would be a good place to start my investigation of digital volume control even though there are many industry specific chips out there to manage some of these functions as well as chips that offer much larger feature sets. With this circuit I hope to expand on the features to create new volume control and measurement circuits – perhaps while investigating the value in using an more advanced volume control chip.

This circuit could be used for replacing your manual volume control in a stereo amplifier. In this circuit, push-to-on switch S1 controls the forward (volume increase) operation of both channels while a similar switch S2 controls reverse (volume decrease) operation of both channels.
Here IC1 timer 555 is configured as an astable flip-flop to provide low-frequency pulses to up/down clock input pins of pre-setable up/down counter 74LS193 (IC2) via push-to-on switches S1 and S2. To vary the pulse width of pulses from IC1, one may replace timing resistor R1 with a variable resistor.

Operation of switch S1 (up) causes the binary output to increment while operation of S2 (down) causes the binary output to decrement. The maximum count being 15 (all outputs logic 1) and minimum count being 0 (all outputs logic 0), it results in maximum and minimum volume respectively.

The active high outputs A, B, C and D of the counter are used for controlling two quad bi-polar analogue switches in each of the two CD4066 ICs (IC3 and IC4). Each of the output bits, when high, short a part of the resistor network comprising series resistors R6 through R9 for one channel and R10 through R13 for the other channel, and thereby control the output of the audio signals being fed to the inputs of stereo amplifier. Push-to-on switch S3 is used for resetting the output of counter to 0000, and thereby turning the volume of both channels to the minimum level. — Sheena K. for electronicsforu magazine

Dual-Channel Digital Volume Control Circuit (click to enlarge)

The LTspice Simulation

The Circuit

Volume Controller Schematic in LTspice (click to enlarge)

The Simulation Results

LTspice Simulation Results (click to enlarge)

In this post I describe how flexible LTspice can be as a general SPICE circuit simulator, and how accurate its behavior can be in comparing LTspice test results with the physical IC’s datasheet. In this example I use the CD4066B as the IC to model. I test the model using its characteristic “on” resistance curves under various voltage and current operating conditions. I conclude by using a standard CD4066 datasheet to verify the accuracy of the model.

Meanwhile this is the last IC I need to simulate the analog section of the digital volume control circuit using LTspice I mentioned in two of my previous blog entries:

• Digital volume control’s heart beat: Simulating the 555 IC with LTspice and
• Digital volume control’s logic: Introducing 74HC193 Simulation to LTspice.

Define one of four bilateral switches on CD4066 for LTspice

To get the CD4066 IC into my circuit simulation, I first created a symbol for one of the four bilateral switches in this package, and defined a SPICE subcircuit definition for the switch using existing SPICE CD4007 gate models as the starting point.

Symbol for one of four bilateral switches on the CD4066 IC

LTspice symbol for one of four bilateral switches on cd4066 (click to enlarge)

LTspice Subcircuit Definition for CD4066
Note the LTspice implementation of the SPICE language is highlighted (below) using my own GeSHi language highlighter library with key sections of the language (.model and .subcircuit) hyper-linked into SPICE language definitions that I have created on the contributor pages of this website. SPICE is a difficult language to highlight using GeSHi because many of the SPICE language constructs are so short that they overlap with longer language constructs. I plan to add more language definitions in the future as my circuit models need them, and I continue to find unique look-up algorithms to match GeSHi language highlighter categories.

Testing the CD4066 Circuit in LTspice

Finally, I dragged the symbol with subcircuit models into my LTspice program and ran a series of tests to demonstrate the “on” resistance characteristics associated with the switch at various voltage and current values. Note the multicolored graph showing the resistance curves at various VI levels.

VI curves and circuit schematic for cd4066 bilateral switch under test (click to enlarge)

Get these files from LTspice Yahoo Group

The 4 main files used to create this demo circuit can be obtained from LTspice Yahoo Group. Special thanks to Helmut Sennewald

See the figure below…

LTspice Yahoo Group File List (click to enlarge)

Comparison of LTspice circuit simulation with datasheet

The TI datasheet compares favorably with my simulations. The LTspice “on” resistance curves and values are nearly exactly the same as those shown in figures 2,3, and 4 of TI’s datasheet (page 6) for the range I tested.

At this stage of development in simulating the analog path for my automatic volume control circuit, I see that the “on” resistance curve may create an unstable signal path under normal audio conditions unless the operating voltage (Vcc ) is much higher than the original circuit’s proposed 5 VDC power supply.

References

Linear Technologies LTspice Landing Page

Texas Instruments datasheet for the CD4066B

What’s All This CD4007 Stuff, Anyhow?
Bob Pease | ED Online ID #6073 | April 5, 1999
http://electronicdesign.com/Articles/ArticleID/6073/6073.html

Fault in CD4066 Model
kcin_melnick | LTspice Yahoo Tech Group Message #16897 | June 24, 2007
http://tech.groups.yahoo.com/group/LTspice/message/16897

Technorati Claim Tag
SH66YHJAPDBA

Technorati Tags: bilateral switch, cd4007, CD4066, Helmut Sennewald, ltspice, simulation

Embedded Components and Tools forum: December 2011

The forum introduces real-time embedded systems technology designed, reviewed, or filmed by Ron Fredericks. Ron focuses on hardware, software, and cloud services for the embedded systems industry through the EmbeddedComponents.com platform and his Bay Area media lab located in Sunnyvale California called LectureMaker LLC.

Embedded Components and Tools forum: December 2011 Welcome to the Embedded Components and Tools forum. The forum introduces real-time embedded systems technology designed, reviewed, or filmed by Ron Fredericks. Ron focuses on hardware, software, and cloud services for the embedded systems industry through the EmbeddedComponents.com platform and his Bay Area media lab located in Sunnyvale California. IN THIS ISSUE NEWS LectureMaker offers video production services designed to promote the unique and often unseen aspects of embedded systems hardware, and software products. FEATURE Self-balancing Two-wheel Robot with Nucleus and TI’s Stellaris Development Kits FEATURE Nucleus ReadyStart on TI Integra OMAP L-138 SPONSOR Become a sponsor of the forum. Get an innovative technical marketing boost from the EmbeddedComponents.com publishing platform.   NEWS   Ron Fredericks offers high quality video integrated into his technical marketing service to the embedded systems business community. After Ron Fredericks launched the Embedded Components and Tools Marketplace™ in 2004, one of the most common suggestions was to include full featured video as a presentation format. Today Ron operates a complete line of video services to help companies leverage the latest new media technology for their sales, marketing, support, and training needs from his Sunnyvale California media lab called LectureMaker. Services include: In-studio and live event video recording and animation Public speech training and video script development Webinars with integrated video and dial-in phone conferencing Video hosting and publishing with source code highlighting and cross-domain hosting from your own website Video integrated blogging on popular social media platforms including wordpress, twitter, facebook, and linkedIn Today’s forum issue features two videos produced in LectureMaker’s video studio from Mentor Graphics Embedded Software Division. Here is what the director of the Nucleus product line had to say about the video projects… "Ron Fredericks produces high impact videos for the embedded systems industry. I met Ron while we both worked at Wind River. Even then Ron demonstrated his passion for integrated embedded systems marketing programs with video as he filmed and published events for reuse by partners and global employees. I have used Ron’s video studio at LectureMaker in Sunnyvale to produce two Nucleus RTOS videos with excellent results and quality. Ron is easy to work with and very knowledgeable in both the video and embedded systems industries." – Jan Klube, Nucleus Product Line Director, Mentor Graphics Embedded Software Division   FEATURE Self-balancing Two-wheel Robot with Nucleus and TI’s Stellaris Development Kits Introducing Stella – a remote controlled, self-balancing robot powered by Mentor Graphics Nucleus RTOS and developed with Sourcery CodeBench also from Mentor. Arvind Raghuram, a software engineer from Mentor Graphics Embedded Software Division, developed this demonstration using a stock TI Stellaris development board and TI’s ZigBee wireless kit. Stella showcases embedded system features such as connectivity, power management, and low footprint while maintaining real-time characteristics. Arvind flew into the Bay Area from his Atlanta Georgia office to develop a short video around his new robot at Ron’s Sunnyvale California media lab. The video and details on Arvind’s project are posted on Mentor’s web site here: Stella Self-Balancing Robot Technology Overview Page   FEATURE Nucleus ReadyStart on TI Integra OMAP L-138 Nucleus ReadyStart provides a single real-time embedded software development distribution that offers fast bring-up of a complete system starting with a rich selection of board support packages (BSPs) along with Mentor Embedded Sourcery Tools, integrated Inflexion UI, and power management services. James Parker, a field sales engineer from Mentor’s Atlanta Georgia office, came to Ron’s media lab in Sunnyvale California to film his Nucleus ReadyStart demonstration on a TI Integra OMAP L-138 hardware kit. The video and details on Jame’s project are posted on Mentor’s web site here: Nucleus ReadyStart on TI Integra   SPONSOR Become a sponsor of the forum. Get an innovative technical marketing boost from the EmbeddedComponents.com publishing platform in action. Contact Ron Fredericks or send email to the forum to participate in this newsletter.     Best regards,  Ron Fredericks, Embedded Systems Technical Marketer Send e-mail to: forum@embeddedcomponents.com Subscribe for free: www.embeddedcomponents.com/pubs/lists/?p=subscribe&id=1 Visit the Embedded Components Marketplace and Training Portal: www.embeddedcomponents.com/marketplace/ Popular Blog Posts   LTspice My First Simulation New Gate Design New Component for the LTspice Community Linear Technologies’ LTspice Landing Page   Popular Marketplace Presentation Ptolemy Project Simulating Predictable Real-time Software Design UC Berkeley’s Ptolemy Project Home Page   © Copyright 2011, LectureMaker LLC

Technorati Tags: Embedded Software, Inflexion UI, Integra, L-138, Mentor Graphics, Newsletter, Nucleus, OMAP, Power Management, ReadyStart, Robot, RTOS, Sourcery CodeBench, Sourcery Tools, Stellaris, ZigBee

Enjoy…

Technorati Tags: Ron Fredericks, youtube, LectureMaker, screencasting, USB, eSTATA, partition

Wind River gets a second chance on connecting smart devices into the enterprise world.

One of their previous attempts was Wind’s office political initiative into Embedded BSD/OS. I thought the BSD OS play was great for Wind River if only they connected their robust multi-core OS from the smart device into the enterpise. Now I see and hope that Wind River has learned from this prior effort and is off to a second chance.

The Wind River Hypervisor

So there are a few different kinds of hypervisor: here is a link to a short discription of the server OS, versus their type 1 and 2 hypervisors. Follow Wind River to learn more about their vision for an embedded system hypervisor.

Now of course the cloud is more tied to the embedded system world than ever. Just look at UC Berkeley‘s upcoming annual technology day called BEARS, where CAL’s EE and CS researchers share with the technology industry.

I sure hope Wind River will be attending!

This year’s 2010 Berkeley EECS Annual Research Symposium event is called: From Clouds to Sensors – A Berkeley View

The CAL BEARS 2010 Symposium view from the clouds

Ron has been in the enterprise, embedded systems, and smartphone technical marketing and partner development for the past 15+ years. Contact him to learn more about how relationship marketing can be used to connect the embedded systems hypervisor to the enterprise clouds with effecient use of industry and university partnerships.

Technorati Tags: Ron Fredericks, Wind River, Hypervisor, Mark Hermeling, multi-core, virtualization, Embedded BSD/OS, UC Berkeley, From Clouds to Sensors

Enjoy…

Technorati Tags: Ron Fredericks, google android, developer ecosystem, LectureMaker, Marko Gargenta, marakana, Software Developer Forum

Panel:

• Bo Cowgill, Google
• Itamar Rosenn, Facebook
• David Smith, REvolution Computing
• Jim Porzak, The Generations Network

Moderator:

• Michael E. Driscoll, Dataspora LLC

The R and Science of Predictive Analytics: Four Case Studies in R

Learn more and watch lecture

Watch this video to learn about:

1. The open-source analytics programming language called R
2. How Google and Facebook approach analytics to predict their web user community’s behavior
3. Where to download R and get enterprise level support
4. How the meeting co-chairs use R

Technorati Tags: Ron Fredericks, Predictive Analytics World, LectureMaker, Bo Cowgill, Google, Itamar Rosenn, Facebook, David Smith, REvolution Computing, Jim Porzak, The Generations Network, Michael E. Driscoll, Dataspora LLC, R, Predictive Analytics, behavior

The marketing bubble‘s effect on embedded device software developers

Introduction

Ron Fredericks writes: In yesterday’s marketing webinar: Beyond Monitoring: Managing Social Media Engagement by SocialRep‘s CEO, Chris Kenton, viewers were riveted by his inside knowledge on social media’s word-of-mouth marketing. Chris is well known for his combination of social media marketing knowledge as well as his ability to strip away the facts from the hype.

To set the stage, my own readers have found my marketing FAQ to be a very popular read for the embedded device software industry: Assessing marketing’s critical role in organizational performance. Read on to see if it will blend!

The Marking Bubble Defined

Chris introduced us to the “marketing bubble”, a marketing event in progress now. Chris may be the first to realize and share the underlying problem so clearly. Marketing has always been a word-of-mouth vehicle since the beginning of human conversations – we’re just not old enough to know it!

Check out the Word Of Mouth Marketing Association’s definition of word of mouth marketing. Chris made the case that professional marketers’ tools over the past 130 years have managed to bypass the value of word of mouth by blasting their messages into public and commercial communities to literally overpower the word-of-mouth model using Print, Radio, TV, Mass Markets, and the Internet. Yet the marketing bubble is now bursting as the Internet continues to host an exploding number of social media tools: – tools that extend word of mouth conversation through online social media platforms, popular content management sites, and even a new form of in-person meet up tool that can quickly assemble like-minded individuals into localized events.

Here is a short list of some of the more common word-of-mouth social media platforms that can be leveraged as microsites:

• LinkedIn: A how-to example
• Squidoo: A how-to example
• Facebook: A how-to example
• YouTube: A how-to example [will it blend]
• Ning: A how-to example
• Twitter: A how-to example
• Meetup: A how-to example

These platforms are also some of the leading causes for the marketing bubble. Check out http://www.alexa.com for further research into tools that specialize by industry and/or region.

These microsites often include application programmable interfaces (API’s), news feeds, user profiles, links to friends, groups, photos/videos, chat, and their own markup languages to build relationships and quickly share short conversations. These features are a little different than the more traditional social media platforms such as blogs, forums, wikis, chat, and idea managers.

Word-of-Mouth Customer Relationship Lifecycle

Chris presents an integrated marketing plan that starts with several forms of monitoring to measure influential conversations followed by use of a wide selection of social media tools.

Monitoring Social Networks: Metrics

Monitoring social media activity is one of the basic requirements to managing social media engagements. A company starting up with a social media marketing program nearly always intends to find and engage with their most influential online customers. But Chris goes on to point out that companies often fail in their use of social media marketing tools. The problem boils down to the fine art of adapting to the trends their team discovers after their initial engagements with social media. I call this the company’s analytics culture. There are thee areas that a company can monitor:

• Media: The web pages and web sites that customers use or visit [commonly monitored]
• Technology: The technology behind a company’s products [often ignored], and
• Finance: The financial goals surrounding a company’s sales activity [often ignored].

The problem stems from a company’s tendency to focus too much on web page tools that monitor media, and in so doing, fails to develop an adaptable action plan that includes the other two key domains of marketing operations: technology and finance. After Chris pointed this out in his webinar, it seems very clear to me that a company needs more than trends in page clicks or page visitors to build the business case for change within a company’s executive team decision-makers. Two solutions that have become popular by social marketers in bridging the gap between initial engagement, and adapting their business activities towards the needs of the community, are in the reuse of these two popular tools already in use by most companies:

• Integration of the company’s Goggle AdWords data, and the
• Integration of the company’s CRM – SalesForce.com in particular.

Using Monitored Results: Analytics

Chris and others point out that although the use of CRM tools are well intentioned – a large percentage of marketers do not get the needed monitoring data to successfully adapt to changes or to meet the changing needs within the company’s community. Chris describes how a company can use their CRM as part of an integrated analytics strategy:

• Use reports and analytics stored within the CRM
• Integration of a word-of-mouth program integrated with the CRM
• Creation of an advisory board from the most influential customers identified from CRM

Building a Program

Chris then presented a Word-of-Mouth program built around a Customer Relationship Lifecycle. He goes over some details, shows some steps to be taken, and highlights a case study. I summarize his program from a B2C perspective here:

1. Awareness:
   • Value: Branding
   • Tools: Web ads, Search engine optimization or marketing, Viral video, Targeted community sponsorship
   • Marketing framework: Conversation + Content
2. Knowledge:
   • Value: Branding and Marketing
   • Tools: Landing pages, Microsites, and Webinars
   • Marketing framework: Conversation + Content + Community
3. Consideration:
   • Value: Branding, Marketing, and Sales
   • Tools: Reviews & comparisons, Hosted chat, and Webinars
   • Marketing framework: Conversation + Content + Community
4. Selection (or when a customer takes the desired action like buys the product):
   • Value: Branding, Marketing, and Sales
   • Tools: Online discount offers, and Hosted chat
   • Marketing framework: Conversation + Content + Community + Customer advisory council
5. Satisfaction:
   • Value: Branding, Marketing, and Sales
   • Tools: Surveys, Support forum, Support chat, and Customer communities
   • Marketing framework: Conversation + Content + Community + Customer advisory council
6. Advocacy:
   • Value: Branding and Marketing
   • Tools: Referral offers, Peer forums, Product networks, and Consumer communities
   • Marketing framework: Conversation + Content + Community + Customer advisory council
7. Loyalty:
   • Value: Branding
   • Tools: Discounts, Insider forums, Product networks, and Customer communities
   • Marketing framework: Conversation + Content + Community + Customer advisory council

Some steps along the way in the execution of a word-of-mouth customer relationship lifecycle program:

• Engage in useful conversations:
  • Targeted monitoring and metrics,
  • Managed engagement,
  • Trend tracking,
  • Media, pundit, and influencer profiling.
• Create a cross-functional Social Media A-Team:

• Marketing,
• PR,
• Product marketing,
• Sales,
• Customer service,
• Engineering, and
• Legal.

• Assign a domain to each member:
  • Where are people talking about your domain,
  • What are people saying, topics, trends,
  • What opportunities are there to get involved,
  • What do we want to spend energy talking about.
• Create a place were you can profile these domains, aggregate, and share information:
  • Meet weekly
• Assign at least one “SocialRep” to manage the engagement process
• Buy a solution only when the process is well defined and in place
• Test and continually question monitoring metrics
• Hire a Marketing Engineer, to address data integration

Some Final Thoughts For Embedded Device Software Developers

Most of what I summarize above is focused on B2C relationships and comes out of my review of Chris Kenton’s great webinar: Beyond Monitoring: Managing Social Media Engagement. Of course I added my own knowledge and some additional references to help my readers get a fast overview of the landscape.

Building a social media marketing program would have some differences when it comes to software developers focused on embedded devices including:

• A smaller volume of activity
• A scarcity of good marketers and public communicators with a working knowledge of the deeply technical subject matter and its assocated value chain
• A larger barrier between the engineers who make and use software:
  • Those that build the software tools targeting a wide variety of programmers, engineers, and architects,
  • Those that create the run-time device optimized software platforms targeting embedded software engineers, and
  • Those that build the differentiating applications targeting the end user.
• A different marketing framework focused on the collective business and not the individual:
  • See Four Steps to Creating a Gorilla Partnership for some insight on building business-to-business frameworks
  • Perhaps the framework will have unique features for open-source vs. OEM software license models
• Look for social media marketing tools that integrate with software developer frameworks, perhaps as plugins
  • Basic collaboration for developers looks like code check-in and check-out for global teams, not like a tweet.
  • Maybe the next tweet will be a twitter plugin that adds another Eclipse perspective, for example.

Yet there can be no doubt that the short word-of-mouth conversations on microsites will burst the marketing bubble. This would be true for any marketer planning there next engagement, for businesses focused on building software for embedded devices, or for the device manufacturer trying to leverage software developers. Chris Kenton’s marketing webinar: Beyond Monitoring: Managing Social Media Engagement is a good place to start building a word-of-mouth marketing plan. His offering demonstrates the most integrated set of tools I’ve seen – to build a substantial word-of-mouth marketing program.

Thanks to Chis for making it very clear that social media word-of-mouth marketing is not a program to be considered independently of other marketing activities. Instead it’s just a mater of time before the bubble bursts in your market sector. The real question is more of when, than if, a company should add word-of-mouth social media tools to their integrated marketing strategy.

Technorati Tags: marketing bubble, software developer, Ron Fredericks, SocialRep, Chris Kenton, social media, marketing, embedded device, software, word-of-mouth, Print, Radio, TV, Mass Markets, Internet, social media, LinkedIn, Squidoo, Facebook, YouTube, Ning, Twitter, Meetup, microsites, blogs, forums, wikis, chat, idea managers, Customer Relationship Lifecycle, conversations, analytics, Media, Technology, Finance, Goggle, AdWords, CRM, SalesForce.com, Awareness, Knowledge, Consideration, Selection, Satisfaction, Advocacy, Loyalty, Social Media A-Team, Marketing Engineer, collaboration

Technorati Tags: Marketing, Marketing Bubble, Social Media, Word-of-Mouth

My WordPress blog on this site is well protected thanks to Akismet. They also have a Drupal project too: drupal.org/project/akismet

You can follow my Drupal site blog – as a work in progress – from here:
www.ronfredericks.net/drupal-6.4

Technorati Tags: Ron Fredericks, Drupal, Akismet

Technorati Tags: Akismet, Blog, Drupal

Ron Fredericks writes: I have completed the design and test of a new component for LTspice/SwitcherCAD III circuit simulation and schematic capture. In a previous post I discussed my interest in the 74193 presettable synchronous 4-bit binary up/down counter IC for a digital volume control circuit I am building. The circuit simulation described below focuses on how to simulate the 74HC193 IC, but timing and voltage parameters built into this design allow a designer to easily simulate other variants of this IC from high speed Si-gate CMOS HC and HCT devices to low power Schottky TTL devices.

All circuits related to this 74HC193 simulation are available here>

The 74HC193 Component

See figure 1 below for a screen shot of the completed design. The circuit was built from the digital gates in the component library supplied with the original Linear Technology‘s free LTspice tool.

Figure 1 – 74HC193 Circuit and Related Components

View larger image>

To keep the design looking like the original data sheet logic diagram, as published by companies that include NXP Semiconductors and Texas Instruments, a custom “T notS-R FlipFlop” subcomponent and corresponding assembly file was first created. This subcomponent was reused 4 times in the main IC logic diagram. An assembly file called 74hc193.asy was also created. It includes all pins used on the commercial IC except ground and Vcc. The IC’s internal power supply is not simulated by the Linear Technologies’ gates, and so they are not used or required in this design either.

Each gate within the design has a few variables assigned to them so that the IC remains flexible and easy to reuse in new projects:

• tdgate td (propagation time delay assigned to each gate)
• tdgate2 td (propagation time delay assigned to the D FlipFlop)
• tripdtgate tripdt (td’s accuracy band assigned to each gate including the D FlipFlop)
• vhighgate logical high value for each gate and D FlipFlop
• vlowgate logical low value for each gate and D FlipFlop

These variables can be assigned their corresponding time and voltage values using a .param statement placed in the main circuit. These values are then within scope for automatic reuse by the 74HC193 component and flipflop subcomponent simulations. Below is an example of how parameter assignment can be made (as used in the test circuit described next):

.param tdgate=10n tdgate2=3*tdgate tripdtgate=1n vhighgate=5v vlowgate=0v

The Test Circuit

See figure 2 below for a screen shot of the completed simulation test circuit.

Figure 2 – 74HC193 Test Circuit and Truth Table Waveforms

View larger image>

The test circuit demonstrates the use of the 74HC193 component assembly.

Individual pulse voltages are applied to the component’s input pins to validate the new device:

• (asynchronous master reset) pulsed high at the beginning and end of simulation. Unlike the waveform often shown in the 74xx193 IC’s datasheet sequence diagram (see page 7 of 29 in this version published by NXP), the second reset pulse was added to insure that Q0 to Q3 output values really do reset.
• (asynchronous parallel load) pulsed low near beginning of simulation to set flip-flop outputs (Q0 to Q3) to the data input values (D0 to D3).
• (rising edge triggered count up clock) pulsed low several times to demonstrate both the count up behavior of the flip-flop outputs and the terminal count up, or carry, () output.
• (rising edge triggered count down clock) pulsed low several times to demonstrate both the count down behavior of the flip-flop outputs and the terminal count down, or borrow, () output.
• to (data input pins) tied to either logic-high or logic-low for this simulation. The logic-low is constructed from a zero voltage component instead of simply being tied to the LTspice global circuit common node (ground). This is because of the LTspice gate component’s special behavior in removing the simulation of individual gate pins tied to the common node ground.

All voltage sources are referenced using the same high and low voltages described in the previous section: vhighgate and vlowgate. These values can be reassigned to all gates, all at once, using the .param statement discussed above.

Download the Circuits

The 74HC193 component, subcomponent, assemblies, test circuits, and plot control files can all be downloaded without restriction in their use. The datasheet supplied does have some licensed use restrictions, as defined in its last page. The reference to the 74HC193 data sheet from NXP Semiconductors is in no way an endorsement of the company or its products, but it is the most recent and best documented behavior for this device that I have found.

1. 74hc193.74hct193.pdf 74HC193 data sheet published by NXP Semiconductors in Adobe Acrobat PDF format
2. 74HC193_test.asc test circuit as shown in figure above
3. 74HC193_test.plt plot control file used by the test circuit above
4. 74HC103_test2.asc debug circuit used to debug errors in original design
5. 74HC103_test2.plt plot control file used by the test2 circuit above
6. 74HC193.asc circuit component
7. 74HC193.asy circuit component assembly used in the test circuit above
8. TnotSRFlipFlopFromD.asc circuit subcomponent used by 74HC193.asc file above
9. TnotSRFlipFlopFromD.asy circuit subcomponent used by 74HC193.asc file above
10. The screenshots saved as png files – as shown in this blog post
11. readme.txt text file granting a license to use the 74HC193 simulation files listed above without restriction and without warranty

Download the files listed above for your LTspice designs all in one zipped directory.

Technorati Tags: Ron Fredericks, component, LTspice, SwitcherCAD III, circuit simulation, schematic capture, 74193, IC, circuit, simulation, timing, voltage, CMOS, Schottky, TTL, Linear Technology

Technorati Tags: circuit, ltspice, schematic, simulation