LONDON Anadyne Microelectronics Ltd. has announced its first product, the AN10E40, a re-spin of a switched-capacitor field-programmable analog array developed by Pilkington Microelectronics Ltd. and sold to Motorola in 1997.
Anadyne (Crewe, England) was founded by Ludwig Klingenbeck and Ian Macbeth, both of whom left Motorola after purchasing its field-programmable analog array (FPAA) technology.
The 5-volt AN10E40, the first of a family of parts based on different array sizes, is a 4 x 5 array of 20 programmable analog cells surrounded on three sides by 13 analog I/Os. Each cell comprises an operational amplifier, a number of switches and five 8-bit programmable capacitors. Although an analog bandwidth for the device was not quoted, the switched-capacitor technology relies on a clock and the maximum allowed is 1 MHz, setting a Nyquist limit for the device of 500 kHz.
Macbeth, who led the development of the FPAA technology at Pilkington (Northwich, England) and then at Motorola, is chief technology officer at Anadyne. He said the FPAA is good for frequencies above the audio spectrum up to a few hundred kHz and that most industrial signal conditioning is conducted at lower frequencies.
The PC-based FPAA design software, called AnadyneDesigner, is a rewrite of Motorola's EasyAnalog. It provides a library of about 50 analog functions that can be mapped to configurable analog blocks. Signals can be linked to nearest-neighbor blocks or across the matrix using a two-tier routing system that is similar to those found in digital field-programmable gate arrays (FPGAs). Developers drag and drop functions into the cells and make signal connections on-screen. A simulator, not yet implemented, will show signal voltages before a device is programmed up, Anadyne said.
Analog signal conditioning functions such as offset removal, rectifiers, gain stages, comparators and first-order filters can be implemented using just one cell. More complex functions high-order filters, oscillators, pulse-width modulators and equalizers can be implemented using two or more cells.
The AN10E40 is almost identical to Pilkington's DPAD3, described on its Web site in 1995, and the part Motorola implemented in 1-micron technology in 1997.
Armed with a list of 1,000 "seriously interested" prospective customers garnered from marketing efforts at Motorola, Anadyne believes its SRAM-configured FPAA technology will succeed where efforts from IMP Inc. (San Jose, Calif.) and Zetex plc (Oldham, England) have failed in setting the market on fire.
Anadyne faces competition from Lattice Semiconductor Corp. (Hillsboro, Ore.), which launched its ispPAC programmable analog technology in November 1999.
What makes Anadyne believe it will succeed with the FPAA this time around?
"In the six months of introduction at Motorola we got a tremendous response," said sales and marketing director Klingenbeck. "That was one of the main reasons we were motivated to form Anadyne."
Mike Kay, president and chief executive officer of Anadyne, stressed the benefits that field-programmable hardware offers over custom analog integrated circuit development. "Engineers currently face a choice between analog implemented with discrete components or custom analog with NRE nonrecurring engineering charges and turnaround time issues. The more the system designer can do from a software basis the better," he said.
Programmable analog circuits have not previously been well-received in the market. Macbeth said Anadyne's switch-capacitor technology allows analog functions to be isolated and abstracted away from the implementation to a much greater degree than other technologies and related design software, which makes its offering superior.
Although it is difficult to fabricate MOS capacitors with accurate values tolerances can vary by 20 percent absolute values from component to component are tightly matched, allowing for very precise ratios.
"The underlying architecture is constructed to meet the range of conditions that users will meet while providing valid compartmentalization so that a function works the same wherever it is placed in the array," said Macbeth.
Switching capacitance can be used to implement RC-equivalent networks in silicon, but it can generate unwanted switching noise.
Anadyne suggests that external resistors and capacitors be used with the I/O cells to build Sallen-key filters for either output smoothing or as anti-aliasing input filters. The AN10E40 also offers two uncommitted op amps at the periphery, allowing fourth-order Sallen-key filters (80 decibels/decade) to be applied to the key input and output signals.
Kay and Klingenbeck agreed that traditional analog engineers are not likely to be the FPAA's prime customers.
Kay said analog engineers are experts at doing things conventionally and would continue to be valued for those skills. However, he said, AnadyneDesigner and the AN10E40 allowed systems engineers and digital engineers to produce similar results in almost zero turnaround time, with no expertise in analog design, no circuit knowledge, no skills with analog simulators or advanced mathematical abilities required.
Anadyne sees two major application areas for its first-generation FPAA. The first is integrating the analog I/O around processor- and/or DSP-based systems in the same way an FPGA does for logic. In that application it will replace large areas of pc board with a single component offering repeatable, drift-free performance.
The second example exploits the ability of the FPAA to be changed dynamically, allowing it to be programmed during assembly to configure the system for the target application.
To foster its approach, Anadyne said it plans to open up its architecture to allow customers and third parties to develop analog functions that can be mapped to its switched-capacitor and op amp configurable analog blocks. It is also providing the AnadyneDesigner software for free, downloadable from its Web site.
Anadyne said volume manufacturing of the AN10E40 is due to begin at Chartered Semiconductor (Singapore) in September, using a 0.6-micron CMOS process technology.
The company plans to offer parts to customers in volumes of 5,000 to 10,000 at $15.50 each in the fourth quarter of this year.