In his column "Programmable analog's real appeal" (March 14, page 54), Stephan Ohr correctly points out that Cypress' programmable system-on-chip (PSoC) products, priced from 50 cents to $2, have taken SoC price objections off the table. But later in the column, he hesitates to categorize PSoC as having real programmable analog, suggesting that PSoC is not used for "amplifier or amplifier-based filter functions."
As a PSoC application engineer for the last five years, I have been involved with many designs that have real (programmable) analog functionality. Here are just a few:
A microlaw audio compandor. This application required not only the digitization and compression of incoming signals, but also decompression and signal regeneration. A six-pole reconstruction filter was required.
A pyroelectric infrared motion detector used for security applications. It required 48 dB of amplification and bandwidth-limiting filters.
Numerous thermistor-based thermometers, used for everything from monitoring lithium battery charge cycles to tracking the temperature of high-energy medical devices requiring patient contact.
An ultrasonic motion detector that required the generation of a 40-kHz transmission signal and an analog synchronous detector to measure the Doppler effect caused by moving objects.
Many of the 190 application notes found at www.cypress.com for programmable systems-on-chip illustrate how the PSoC can perform real analog functionality. Long gone are the days when an embedded design could be broken into analog, digital and firmware sections and parsed out to three designers.
Today's applications require engineers that are capable of complete system design. Programmable systems-on-chip-including programmable analog-make this chore easier and more cost-effective.
Dave Van Ess, Principal Applications Engineer
Cypress Semiconductor Corp., Lynnwood, Wash.