Silicon thermistors provide more accurate temperature sensing, optimizing system performance

Chandler, AZ – Feb. 16, 2004 – Andigilog, a fabless analog and mixed-signal semiconductor company, today announced the SiMISTOR family, the industry's first cost-effective, linear and highly accurate silicon thermistors. SiMISTOR products, manufactured using mature CMOS processes, can replace traditional thermistors in high-volume cell phones, PCs and peripherals, PDAs, and consumer device applications. The new SiMISTOR family also readily displaces thermistors in traditional industrial applications, such as thermostats and portable medical devices.

The new SiMISTOR silicon thermistors measure temperature to 1 degree Celsius and provide a linear voltage output proportional to temperature, making the SiMISTOR family more accurate than traditional thermistors. The architecture of the SiMISTOR family provides for improved bill-of-material costs by reducing the complexity of the system required to measure temperature.

The linearity and accuracy of the SiMISTOR family products eliminate expensive analog-to-digital converters, look-up tables and complex processing equatio ns that traditional thermistors need to get an accurate temperature measurement. In addition, SiMISTOR sensors are calibrated during the manufacturing process, eliminating lot-to-lot variations found in traditional thermistors.

SiMISTOR family product features include:
– Accuracy of 1 C at 25 C
– Operating Range: -40 C to +125 C
– Non-linearity < 0.8 C
– Single supply voltage
– Calibrated during manufacturing
– Extremely linear output ramp
– Slope and offset choices to optimize system accuracy over desired range
– Low operating current of less than 35 A (aSM120) or less than 14 A (aSM121, aSM122)
– Low self-heating: 0.2 C maximum in still air
– Tiny, leadless quad packages are smaller than packaging for conventional silicon sensors and thermistors

The SiMISTOR family includes the aSM120, aSM121 and the aSM122 sensors. The aSM120 sensor operates with either a traditional series resistor or a current source. It has an operating voltage range of +2.7V to +6V. The aSM120 sensor offset voltage at 0°C is +2V with an output temperature slope of 10mV/°C. The aSM121 and aSM122 sensors do not require the traditional series resistor for the output voltage. They have a specific pin for output temperature. These parts also have an operating voltage range of +2.7V to +6V. The aSM121 sensor has an offset of 500mV at 0° C with an output temperature slope of 10mV/°C, while the aSM122 has an offset voltage of 600mV at 0°C with an output temperature slope of 15mV/°C.

In many computing and consumer applications, space is at a premium. Andigilog's SiMISTOR products offer the smallest packaging available for a silicon thermal sensing device. The family comes in quad flat no-lead (QFN) plastic packages with a maximum of 0.8 mm (height), with the aSM120 sensor packaged in a two-lead version (1.3mm x 0.9mm) and the aSM121 and aSM122 sensors packaged in three-lead versions (1.2mm x 1.5mm).

The aSM120, aSM121 and aSM122 products are sampling now, with volume production beginning Q2 2004. The pricing for the aSM120, in the two-lead QFN package, is $0.49 per unit U.S. in 1K unit quantities. The pricing for the aSM121 and aSM122, in the three-lead QFN package, is $0.35 per unit U.S. in 1K unit quantities. An evaluation kit is available now, free of charge.

For more information, to order samples and evaluation kits, or to get information on local product representatives, go to or call +602-940-6200.

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