Andigilog’s temp sensors smarten up

Tempe, Ariz. — Andigilog, a fabless analog and mixed-signal semiconductor company providing temperature sensing and other components for the cellular, personal computer and industrial markets today announced the first device in an upcoming digital family of intelligent thermal management solutions.

The aSC7511 intelligent thermal management sensor monitors temperature locally and remotely using Andigilog's unique temperature sensing technology to provide accuracy of ±1°C. By sensing temperature more accurately, these solutions will help improve overall performance and help reduce power consumption in notebook and desktop PCs utilizing processors such as the Intel Pentium 4 processors and the AMD Athlon and Duron processors.

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Andigilog's ASC7511 Block Diagram

Thermal management continues to be a critical issue in personal computers as overall system size decreases and processor speeds increase. Fans to cool these systems create noise and consume power, while overheated systems can crash or damage data or other components. To reduce heat and prevent system failures, manufactures create a margin of safety, known as guardband. More accurate sensing of the actual temperature of systems allows manufacturers to reduce guardband, which results in systems that can run faster for longer periods of time.

“Thermal management has emerged as the leading hurdle to improving system performance and reliability,” said Mark Gordon, director of marketing for Andigilog. “User demand for more performance, more battery life and smaller devices means that heat must be sensed and managed more effectively. We are evolving our unique accuracy in sensing to a family of intelligent thermal management products, with the aSC7511 as the first in a series of solutions.”

The aSC7511 sensor is based on Andigilog's SiMISTOR CMOS-based silicon temperature sensor introduced in 2004. It has on-chip and remote temperature sensing with user-programmable trip temperature and turn-off temperature registers.

Key features of the aSC7511 include:

  • Remote sensor accuracy: ±1°C
  • Internal accuracy: ±3°C
  • 3 and 5 V operation
  • Therm/alert signals
  • Offset register for system calibration
  • Selectable operating ranges of 0°C to 127°C or -55°C to 150°C for the remote sensor
  • Operating current of fewer than 215μA
  • Low self-heating, 0.2°C maximum in still air

Samples, as well as an evaluation kit will be available in April. Production volume is slated for July.

Pricing for the aSC7511 in either SOIC-8 or MSOP-8 packages is $1.85 each in 1,000-piece quantities.Click here for the aSC7511 data sheet.

Andigilog , 1-480-940-6200,

Andigilog's claim to uniqueness lies within the accuracy of its aSC7511 intelligent thermal management sensor.

In fact, the company guarantees that all of its sensors provide ±1°C accuracy, while competing devices may contain as much as 6°C of uncertainty in similar parts, according to Bill Sheppard, Andigilog's CEO.

A 6°C temperature shift is equal to 11°F. If the temperature in a room, for instance, is set for 74.5°F, it could be as cold as 69° or as hot as 80&deg, which is a pretty significant difference. “If the processor temperature is measured more accurately, less guardband or buffer is required in the system design, meaning the system can run faster for longer periods of time without the fan — thus also conserving battery life in portable devices,” Sheppard said.

Although there could be a 6° temperature difference among competing sensors, you will typically see a 3° temperature difference within a small specified temperature range — such as a temperature sensor with a ±3°C operating within 60°C to 100°C, while Andigilog's aSC7511 sticks to ±1°C over a wide temperature range of -40°C to +125°C, according to Sheppard.

In addition, another way that Andigilog is able to provide such a precise temperature sensor, is by preconditioning the aSC7511 to minimize noise, resulting in a cleaner signal. “Some methods used to sample the signal induce noise causing an additional 1.5 degree temperature difference, compared to ours, which is accurate within a quarter of a degree,” he said.

Andigilog's latest sensor represents a technology migration from analog-based temperature sensors in 2004, to digital remote sensors based on analog building blocks in 2005.

The major difference between the two families is that the older device was geared for cell phones and provided a voltage output proportional to temperature. The newer family, however, aimed at PCs, includes the analog sensor technology and adds the remote digital sensor capability to read diodes from the microprocessor.

Also this year, Andigilog will begin incorporating all of the elements necessary (see the company's technology roadmap slide below), culminating into a total integrated thermal management system by 2006.

This summer, the company plans to add a thermal system controller with pulse-width modulation (PWM) output and a discrete motor control brushless DC fan driver device to its portfolio. Then, an intelligent smart fan version sensor will emerge in 2006, with additional interfaces required for the evolution of PC architectures. Finally, a completely integrated thermal management solution, which will include microcontroller technology, will be available in late 2006.

Andigilog's sensors are intended to help alleviate the temperature dissipation challenges that PC makers are facing with their small systems and fast microprocessors moving from 90 nm down to 65 nm — which generate heat that is difficult to dissipate in small spaces.

Business Communications Company (Norwalk, Conn.) forecasts that the world market for electronics thermal management products will reach $5.9 billion in two years, with computers, representing the largest segment ($2.3 billion).

Intel is addressing thermal management issues by migrating from its advanced technology extended (ATX) CPU form factor cooling architecture to the newer form factor balanced technology extended (BTX). The BTX design places the hot silicon in an air stream so the computer's fans can keep them cool, compared to the older ATX architecture, which is larger, noisier and hotter.

Andigilog's digital remote sensor will enable fans to operate only when needed instead of all the time, which translates to additional battery life, Sheppard said.

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Andigilog's Technology Roadmap

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