Trends in Legacy Parts at Tekmos 

Tekmos is frequently called upon to develop ASICs that our customers can no longer purchase from the original vendors. For projects of this type, the customer may have the original design files which makes the project fairly straight forward. Another type project occurs when it is desirable to produce an ASIC from an FPGA that is no longer available. Tekmos has successfully developed many such devices.

A very different type of project at Tekmos starts when a standard part is made obsolete by a vendor. While a letter usually goes out to customers stating that a part will soon be considered obsolete, customers do not always buy enough parts when the "Last Time Buy" notice is sent. Often this is because the customer cannot accurately predict customer demand on a legacy product. When there is still demand for a customer's obsolete product, he is faced with the difficult decision of trying to buy parts from several distributors, go to the grey market with its questionable part quality, redesign the product, or abandon a product that still has significant demand. One other alternative is to go to Tekmos and ask if Tekmos will build what had been a standard off the shelf part starting from only the datasheet for the part.

Many Tekmos standard parts were brought to life in response to this type customer need. Our website has many parts types that were originally for only one customer but we saw the advantage to many customers if we made the part more widely available. Listing these parts, once developed, makes it easier for other customers to replace that obsolete part. An added advantage of buying the parts from Tekmos is completely eliminating any worry about the pedigree of a part. We only sell parts which we have fabricated so there is no question of their origin.

The standard part type most requested so far this year is our TK80C51FA which replaces Intel, NXP, and Atmel 80C51 families. It is a microcontroller with 256 bytes RAM, A PCA (Programmer Counter Array), and a watchdog timer. The second most requested part type so far this year is the TK87C751 which replaces the NXP P87C51. While it is a derivative of the 80C51, it is designed to provide the 80C751 architecture in a small package with a hardware Two Wire Interface. It has 64K ROM and a 128 x 8 scratchpad RAM. Details are available on our website. The third most requested part type this year has been the TK68HC711E9 which replaces the Freescale MC68HC11E9. The fourth most requested part this year has been the TK80C188EWC which replaces the Intel TN80C188EB. The fifth most requested part type this year to date is the TK68HC11K1 which replaces the Freescale MC68HC11K1. A full description of each of these parts can be found in their datasheets on the Tekmos website www.tekmos.com/products. Intel, NXP, Atmel, and Freescale are trademarks of their respective companies.

Although each of these part types is pin-for-pin compatible with the device it replaces, these parts are not the same part as made by the original manufacturer. Tekmos strongly suggests trying samples of our parts in customer systems before placing an order. We have seen cases where minor parametric differences can cause system issues.

If you have interest in these or other legacy microprocessors, FPGA conversions, or ASIC conversions, please contact us at sales@tekmos.com.