Experienced designers know there are situations in which discrete logic is more cost-effective than an integrated solution. Additionally, certain trends in system design-such as lower voltages, faster switching speeds and rapidly expanding applications like Internet-based data communications-assure a growing need for discrete logic.

Some engineers refer to discrete logic as their best friend. This affinity is easy to understand when you realize the important role logic plays in many designs. An ASIC, for example, may not meet its spec or a certain signal in the final design of a cellular telephone might need to be inverted. Rather than re-spin the entire design and reinvest considerable time and money, inserting a logic device at the critical point in the design will get the system to market on time and within budget.

In many cases, the designers of a new system are under severe pressure to meet deadlines so that the system can be one of the first of its kind to market. The development team doesn't have time to forever improve the base design, tweaking it until it is perfect. Discrete logic can provide the functionality needed and it will help get the new product to market on schedule.

During the next phase of the system's life, the project team has more time to work on the design. The pressure of getting to market has been replaced by a drive toward cost reduction. Now, some of the logic in the original design is integrated into ASICs or other devices, but this isn't the last phase of the system's life. To extend the competitive life and capitalize on the investment in the original development, the project team decides to change the functional- ity slightly, add a new type of interface or supplement the functionality provided by an existing, under-amortized ASIC. Discrete logic is a cost-effective way of meeting these challenges.

Eventually the base design will come to the end of its competitive life. Advances in technology may change the rules of the marketplace, but for whatever reason, another new design for a next-generation system is needed. Now we're back to the start of the cycle, and discrete logic is once more playing a critical role in getting the next new product to market on time.

So we see that the basic nature of a product's life cycle creates a need for discrete logic. The rapid pace of technology development further accentuates the need for logic because new-product development cycles only become shorter, never longer. This adds to the pressure on designers and augments the valuable role discrete logic plays.

Just as product life cycles inevitably shorten, system speeds are bound to increase. We see today an industry-wide move toward lower voltages and higher switching speeds. The two go hand-in-hand, and together they have an effect on signal quality. At faster switching speeds and lower voltages the margin for error at the edges of the highs and lows of a signal is reduced to a bare minimum. Without logic controlling the edges of these fast, low-voltage signals and assuring signal integrity, the industry might not be able to achieve the higher speeds demanded by the marketplace.

A very real indicator of an established technology's future is whether its suppliers are willing to place their money where their mouths are. By this I mean: how much innovation is going on with this technology? How much new thinking is taking place? What imaginative solutions are being introduced to the market?

Take a close look at the leading logic suppliers today and you'll see new innovations in packaging like one-gate devices and ball-grid arrays. You'll see investments in advanced process technologies for logic, like CMOS, BiCMOS and other even more exotic fabrication breakthroughs. You'll see standard, off-the-shelf, reliable logic devices breaking new speed records.

You'll see a resonant and vital market for discrete logic.

— Steven J. Hanke is the director of Worldwide Marketing for Texas Instruments Inc.'S Standard Linear And Logic Products Group (Sherman, Texas).