A new MEMS device from Texas Instruments promises to make non-contact IR temperature sensing much easier and less expensive than existing methods. The TMP006 is a complete single-chip, passive IR temperature sensor with integrated MEMS thermopile, signal conditioning circuitry, 16-bit ADC, local temperature and voltage references, and both I2C and SMBus digital interfaces, all in a chip measuring 1.6 x 1.6 mm.
The thermopile in the sensor device absorbs infrared energy emitted from the object being measured and uses the corresponding change in thermopile voltage to determine the object temperature, with a sensitivity of 7 µV/°C. The operating voltage range is specified as –40 °C to +125 °C to enable use in a wide range of applications, and the typical accuracy is ±1 °C for the passive IR sensor and ±0.5 °C for the ambient temperature sensor.
Low power consumption along with low operating voltage makes the device suitable for battery-powered applications. The low package height of the chip-scale format enables standard high-volume assembly methods and can be useful where the object to be measured is close to the sensor board. According to TI, the new solution is 95% smaller and draws 90% less power than competitive solutions, with an operating current of just 240 μA in quiescent mode and 1 μA in shutdown mode.
An evaluation module is available for USD 50, and an IBIS model is available for assessing and verifying board signal integrity requirements, along with source code for calculating object temperatures.
Image: Texas Instruments