Optimizer called missing analog synthesis link

Optimizer called missing analog synthesis link
SAN FRANCISCO — Analog Design Automation Inc. this week will introduce its long-awaited Genius analog circuit optimizer, a device billed as "the missing link" in the analog synthesis chain.

The optimizer juggles hundreds of variables to find the best IC design trade-offs, increasing the productivity of analog engineering teams, said Matthew Raggett, president and chief executive officer of Analog Design Automation.

"Analog synthesis has been oversold, "Raggett said. "But a circuit optimizer, one that can efficiently identify the trade-offs for a new design, can cut weeks off the design cycle," he said.

Intended for analog designers, whose work often means balancing competing parameters, the Genius tool set looks to speed the process of trying out different component values and feature sizes on analog ICs. Using their own simulators, the Genius tool set will weigh alternatives and graphically reveal points of acceptable compromise, Analog Design said. The tools are meant to speed the creation of reusable analog intellectual property (IP) by "unleashing the genius of analog/mixed-signal designers," said Raggett.

Automated route

Founded in 1999, ADA (Ottawa) is one of the most visible startups advancing "analog synthesis" — the ability to move in a highly automated way from high-level language descriptions to actual hardware implementation, as is commonly done with digital designs.

Other companies pursuing the vision include , Antrim Design Systems and Neolinear Corp. All build on the vision of professor Rob Rutenbar and his associates at Carnegie-Mellon University (Pittsburgh), who taught that analog cells could be created by specifying a circuit topology and then searching a library of transistor circuits that may match to topology, and trying them out with networked simulation engines.

But the success of such a network — the ability to design an analog IC without using a square mile of silicon — was contingent on what was in the library of choices and how fast it can be searched. Each of the so-called "analog synthesis" companies has come at this paradigm from a somewhat different angle.

Barcelona, for example, starts with existing IP from foundries, and challenges designers to modify them for their own needs. The designer sets out the desired parameters and Barcelona's own simulator reports on whether the IC can be built in the chosen process. Much of the analog analysis machinery is deliberately hidden from the user. Barcelona's Web-based methodology is patently geared toward digital designers. But even supporters like Gartner Dataquest's EDA analyst, Gary Smith, refuse to call this technology "synthesis."

Neolinear, similarly, starts close to working silicon. It generates efficient analog cells using an "unsized netlist" (a circuit diagram in Spice, for example), a process map and the user's own simulator. But such tools are more "process retargeting" vehicles than "analog synthesis" tools, Dataquest's Smith maintains.

Fast link

Antrim Design and ADA tools are similar, starting at a relatively high level and working downward toward a silicon implementation. Antrim, which has spread into creating and selling analog IP, maintains that a speedy connection between precharacterized silicon and high-level Verilog AMS models — using Rutenbar/Carnegie-Mellon methods — requires a "guided search," preferably in the hands of an analog expert.

ADA's Genius tools push analog expertise another rung on the ladder: Based on intelligent-systems research — essentially neural-net technology — at the University of Saskatchewan, the Genius tools streamline the searching for and trying out of transistor-level alternatives. While the company has an impressive patent portfolio, its most noticeable advances include automatic worst-case topology analysis, multi-objective decision support, perception-based algorithms for circuit optimization and testbenches for optimizing single-ended and differential amplifiers, voltage references and current mirrors.

Dataquest's Smith called analog circuit optimizers "good practical tools," but wondered how quickly such companies can recover their costs. "There are only 2,000 to 4,000 analog designers in the entire world," he said.

Financial analyst John Barr of Robertson Stephens said the EDA industry will growing from $3 billion in 2001 to $6.3 billion in 2005, with the analog portion of the market growing at a 50 percent annual rate over that same period.