Analog IP rolls for TSMC processes
By Crista Souza, EE Times
December 8, 2003 (3:45 p.m. EST)
SAN MATEO, Calif. The market's interest in handheld electronic devices is introducing requirements for analog circuitry that few system-on-chip designers are equipped to handle.
LTrim Technologies Inc., an intellectual-property (IP) provider based in Laval, Quebec, is hoping to change that. The 23-person company offers analog "virtual components" that can be ingrained in a deep-submicron CMOS design and fine-tuned with lasers.
While suppliers of discrete analog chips apply a thin-film layer on top of a usually bipolar chip to facilitate laser trimming, LTrim integrates resistors right into the CMOS substrate, an approach that eliminates additional process steps and allows for trimming to higher precision, the company said.
"We're producing resistors in CMOS capable of 0.001 percent tolerances-levels unheard of-at a fraction of the cost of using discrete components," said Guy Lemieux, president and chief executive officer o f LTrim.
The company has 18 basic power-management IP blocks proven for the 0.25- and 0.18-micron processes of foundry Taiwan Semiconductor Manufacturing Co., including voltage references, voltage regulators, voltage converters and charge pumps. LTrim said it is working with IBM Microelectronics in a similar vein.
By next summer, LTrim expects to have several more IP blocks for use in 0.13-micron silicon, and over the next 24 months it plans to develop more complex circuits, such as A/D and D/A converters. The company also offers design services and laser fine-tuning, and has developed layout tools that minimize process variations. Circuits are tested in-house over the full military temperature range, LTrim said.
Founded in 1999, LTrim began as a university research project focused on laser trimming, but soon saw in the emergence of systems-on-chip an opportunity for integrating analog functions in digital CMOS, Lemieux said.
The analog knowledge base in the SoC world is small , and designers have resisted analog integration, said sales director Mike Shamshirian. But "as we go down in geometries, people are realizing they have to integrate analog to support multiple voltages on a chip," Shamshirian said. "Also, at 0.13 micron, leakage becomes a big issue, so you need a voltage regulator with tight tolerance."
The LTR4040 voltage reference family offers 25-amp quiescent current, output voltage of 1.214 to 3 V and output current of 20 mA. Output tolerance is 0.8 percent without fine-tuning. The LTR1004 voltage reference has the same output voltage and output current with 10-A quiescent current and 0.5 percent output tolerance without tuning. The LTR1761 low-drop-out regulator family offers 35-A quiescent current, 1.5- to 3-V output voltage and 50- to 250-mA output current.
Under development for 0.18- and 0.13-micron processes is the LTR2001 charge pump, with 50-A quiescent current, 1.8- to 3.3-V input, 2- to 6.5-V output and 10-mA output current.
A single-use license starts at approximately $20,000.