Custom Silicon Solutions, Inc. Newsletter
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July/August 2009
In This Issue
CMOS Serial Digital Pulse
 Width Modulator
CSS is now offering the CSS68HC68W1, a direct replacement for the Intersil CDP68HC68W1 part which is unavailable from Intersil or other sources
 Simulator Model


  • Direct Replacement for Intersil CDP68HC68W1
  • Programmable Frequency and Duty Cycle Output
  • Serial Bus Input; Compatible with Motorola/Intersil SPI Bus, Simple Shift-Register Type Interface
  • 8 Lead PDIP package
  • Schmitt Trigger Clock Inputs
  • 3V / 5V Operation, -40C to 85C Temperature Range
  • 25 MHz Clock Input Frequency
The CSS68HC68W1 modulates an input clock to provide a variable frequency and variable duty-cycle output signal.  Three 8-bit registers (pulse width, frequency and control) are accessed via a 3-line serial interface.
Complete Specification Sheets for this IC may be downloaded from the CSS Website. Specifications for both 5V operation (CSS68HC68W1_Spec) and 3V operation (CSS68HC68W1_Spec_3V) are available. 

The part is offered in an 8-pin PDIP (green) package and is available today, off-the-shelf, from the CSS authorized distributor, Globalwide Electronics Group LLC (  Contact Lance Laviano: Phone: (631) 677-2400, Email: [email protected]

"Itron has been very pleased with the design, project management, and implementation of the custom ASICs that CSS has developed for us. CSS is a preferred supplier and our first choice on new designs. Further, they have done an excellent job of supporting ongoing production."
Kent DeLong

Strategic Purchasing Manager

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(949) 289-9056 
Welcome to the July-August edition of the CSS Newsletter.  We hope you find these articles informative and helpful in your work.

Custom Silicon Solutions (CSS) provides a true Turn-Key Solution to meet your Mixed Signal ASIC needs - from Development through Production.  Our mission is to develop an ASIC that meets your requirement at the lowest possible price and with a minimum of assistance from your technical staff.  Please visit us at for more information or send an inquiry to [email protected].
                                                Keith Shelton

In our last Newsletter, we introduced the CSS555 family of timer ICs.  As you may remember, the CSS555 is a micro-power version of the industry's popular 555 Timer IC.  It is pin-for-pin compatible with the standard 555 timer and features an operating current under 5A and minimum supply voltage is 1.2V, making it ideal for battery-operated applications.  A six-decade programmable counter is included to allow generation of long timing delays.  Also, a version with a built-in timing capacitor is available: the CSS555C.
Simulator Model

The CSS555 in 8P DIP and SOIC
There has been a lot of interest in applications for the CSS555 family, so we have put together an Application Note which describes in detail 20 different applications of the CSS555 and CSS555C.  There has also been interest in using the CSS555 in circuit simulations.  For this purpose we have completed a model that may be used in the SPICE circuit simulator.  
1. CSS555 Application Circuits
The CSS555 Application Note includes 20 example application circuits.  These applications show the advantages of the CSS555C timer and how it can reduce power, decrease PCB area and eliminate the external timing capacitor.  They demonstrate many of the basic 555 timer functions and illustrate how the CSS555 may improve your existing timer circuit's performance.   They may also serve as a basis to develop new applications.  An example application circuit is indicated below.  The CSS 555 Application Note is available on our website.
One Shot with Delay

One Shot with Delay
You will notice in the Application Note that Calculators are used to determine the setting for the CSS555.  These Calculators (CSS555_Timer_Delay_Calculator) and (CSS555_Adj_Duty_Cycle_Calculators) are available for download on the same website page as the Application Note (see above).
CSS also has a Demo Kit that provides a quick and easy way configure the timer's operating modes or to trim the internal timing capacitor.  This Kit includes a PC board, a USB interface to your PC, sample CSS555 devices and a software program to make this task simple and straightforward. 
Simulator Model
PC Card in CSS 555 Demo Kit

2. SPICE Simulation Model
CSS has just released SPICE simulation models for our CSS555 and CSS555C ICs.  These models provide a simulation capability at the component level.  The models are simplified to reduce simulation time but still provide a very good representation of the real IC.
Simulator Model 

SPICE Simulation of a CSS555 Application
The CSS555 Timer Model includes the following features: 
1. Supply Current (over VDD)
2. Input Switch Levels
3. Propagation Delay Time
4. Output Drive (over temperature and VDD)
5. ESD Clamp Diodes and Pad Capacitance
This new CSS555 Simulation Model is reviewed today in the CSS Blog: and may be downloaded from our website. See CSS555_App_Note 2_SPICE_Model.pdf.
Thanks for reviewing our Newsletter article on the CSS555.  Please feel free to send us comments or questions regarding our CSS555 products.  Send email to: [email protected] or call us at: 949-289-9056.
CSS555C Free Samples
If you would like free samples of our new CSS555C Programmable Timer, just Email [email protected] or Call (949) 289-9056.
Also, you may request a CSS555C Demonstration Kit for a reduced price of $35.00.
Mention Promotion Code: FJB01
Offer Expires: August 31, 2009