A linear and highly accurate silicon family of thermistors, dubbed SiMISTOR, bears a price point that makes them available to high-volume cell-phone, computing, consumer, and industrial applications. At costs as low as 35 cents each, Andigilog's SiMISTOR includes the asM120/121/122 sensors.
The thermistors feature ±1°C accuracy at 25°C, just 0.8°C nonlinearity, and an extremely linear output ramp signal. They operate over the temperature range of −40°C to 125°C, run from a single supply of 2.7 V to 6 V, and consume just 14 µA (asM121/122) and 35 µA (asM120). Calibration is done during manufacturing. Also, the devices feature low self-heating of 0.2°C maximum in still air. Slope and offset choices are available for optimal system accuracy over temperature.
The asM120 operates with either a traditional series resistor or a current source and has a 2-V sensor offset at 0°C and an output temperature slope of 10 mV/°C. The asM121/122 don't require the resistor and have a specific pin for output temperature. They feature offsets and output temperature slopes of 500 mV and 600 mV at 0°C and 10 mV/°C and 15 mV/°C, respectively.
Each SiMISTOR thermistor comes in a plastic quad flat no-lead (QFN) package with a maximum height of 0.8 mm. The asM120 is a two-lead version (1.3 by 0.9 mm), and the asM121/122 are three-lead versions (1.2 by 1.5 mm). Samples are available now, and production begins in the second quarter.
In 1000-unit lots, pricing is $0.49 each for the asM120 and $0.35 each for the asM121/122. An evaluation kit comes at no additional cost.