1%-accurate, miniature FIR sensor meets multiple temp sensor requirements
The MLX90632 family is based upon Melexis’ FIR technology; employing an ultra-small integrated thermopile, the CMOS IC is a complete solution in a single 3 x 3 x 1 mm QFN package including the sensor element, signal processing, digital interface and optics, for rapid and simple integration. Ambient light is screen out by an optical filter that passes 2 – 14 µm wavelengths. The chip operates from 3.3V (typical) and delivers measured data over I2C to an external microcontroller. It uses 1 mA active, and under 2.5 µA in standby.
The device is factory calibrated with calibration constants stored in an EEPROM memory. Ambient and object temperature can be calculated based on these calibration constants and the measurement data. Factory calibrated in the ambient temperature range is from -20 to 85˚C and in the object range, from -20 to 200˚C. It is capable of measurement resolution of 0.02C, and accuracy is ±1˚C within the object temperature range of 0 to 50˚C, for consumer applications.
The accurate device delivers high levels of thermal stability when experiencing thermal gradients and rapid temperature changes, solving a well-known weakness of existing infrared sensors. It occupies a surface mounted (SMD) package compatible with standard PCB assembly techniques.
Firs released in a commercial grade version, future versions of the MLX90632 will address, amongst others, medical applications.
Smart device manufacturers can differentiate their products through the inclusion of accurate temperature measurement. Melexis has integrated an optical lens into the device that reduces the field of view to 50º, thereby enabling a higher operating distance and greater measurement accuracy.
Melexis anticipates applications wherever it is important to accurately measure temperature, especially in thermally dynamic environments and when available space is limited. Potential applications can therefore be found in white and grey goods, room temperature monitoring in smart thermostats, server rooms or integration into portable electronics devices such as tablets and smartphones.