National Semiconductor launches world's most precise digital temperature sensor

Citation

(2000), "National Semiconductor launches world's most precise digital temperature sensor", Sensor Review, Vol. 20 No. 3. https://doi.org/10.1108/sr.2000.08720cad.001

National Semiconductor launches world's most precise digital temperature sensor

National Semiconductor launches world's most precise digital temperature sensor

LM92 with better than ±0.33°C to ±1.5°C accuracy over its full operating range

National Semiconductor has launched the LM92, the latest addition to its digital temperature sensor family. The revolutionary LM92 is the world's most precise digital temperature sensor with up to ±0.33°C accuracy (see Plate 1).

The LM92, in addition to giving a digital temperature readout, provides an integrated thermal window comparator making the design of a complete temperature control system easy. A host can program both the upper and lower limits of the window (indicating the temperature control range) as well as programming a critical temperature shutdown limit, via a two-wire serial bus interface.

Plate 1National Semiconductor's latest addition to its digital temperature sensor family - the LM92 - is the world's most precise digital temperature sensor

With a 12-bit + sign analog-to-digital converter (ADC), giving a 0.0625°C temperature resolution, the LM92 achieves better than ±0.33°C accuracy at 30°C without further calibration. The LM92 is a full range temperature sensor achieving accuracy of better than: ±0.5°C, from +10°C to +50°C ±1.0°C, from -10°C + 85°C ±1.5°C, from -25°C to +150°C

"The LM92 is ideal for high-accuracy applications such as heating, ventilation, air conditioning (HVAC), vending and refrigeration systems, medical, test equipment, automotive, cellular base-stations and a host of other applications which typically require high precision", said Mark Holdaway, European product marketing manager for National's data conversion products.

"Prior to the LM92, the only way to achieve similar sensing accuracy was to use costly platinum resistance temperature detectors (RTDs) or carefully calibrated thermocouple solutions. National is revolutionising the business of temperature sensing with the LM92 by bringing to market a low cost, easy to use, precision solution.

Traditional test approaches necessary to enable high accuracy analog sensor solutions have had a significant impact on production throughput. With the new advanced test methodologies employed on the LM92, National can offer a guaranteed precision component in high volume. In fact the LM92 surpasses the accuracy performance of a class B platinum RTD and are arguably easier to use."

A key feature of the LM92 is its excellent linearity of ±0.5°C maximum. Other features include interface compatibility with both I® Bus and SMBus, and a timeout feature to prevent serial bus lock-up. Programmable hysteresis and a fault queue of up to four faults are provided to prevent false tripping when used in noisy environments. As many as four sensors can use the same serial bus. The device's supply-voltage range is 2.7V to 5.5V and for power saving, a low power (5µA) shutdown function is included.

National's extensive portfolio includes many other digital and analog temperature sensing solutions. For customers seeking lower cost alternatives to the LM92, National's existing porttolio includes the LM76CHM and LM76CNM. Both devices headline with an accuracy of ±1°C and are ideally suited for use in electronic test equipment, office electronics, consumer electronics, embedded and bio-medical applications.

The LM92 is packaged in a space-saving 8-lead SOP and currently available in 1,000 unit quantities.

Product enquiries: European Customer Support Centre. Fax: +49 (0) 180 530 85 86; E-mail: europe.support@nsc.com; German: Tel: +49 (0) 69 9508 6208; English: Tel: +49 (0) 870 24 0 2171; French: Tel: +33 (0) 1 41 91 8790.