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MLX90621 16x4 IR array Datasheet Features and Benefits Applications Examples Small size, low cost 16x4 pixels IR array High precision non-contact temperature Easy to integrate measurements Industry standard four lead TO39 package Temperature sensing element for residential, Factory calibrated infrared temperature commercial and industrial building air measurement. conditioning Calibration parameters stored in EEPROM. Microwave ovens Noise Equivalent Temperature Difference (NETD) Home appliances with temperature control 0.20K RMS 4Hz refresh rate Thermal Comfort sensor in automotive Air 2 I C compatible digital interface Conditioning control system Programmable frame rate 0.5Hz512Hz Passenger classification 2.6V supply voltage Automotive blind angle detection Current consumption less than 9mA Industrial temperature control of moving parts Sleep mode consumption less than 7A Identifying thermal leaks in homes Measurement start trigger for synchronization Thermal scanners with external control unit Security / safety gates 3 FOV - 40x10, 60x16 and 120x25 Intrusion / Movement detection Ta -40C to 85C Presence detection / Person localization To -20C to 300C Complies with RoHS regulations Ordering Information Part No. Temperature Package Option Code Standard Packing Code Code - X X X part form MLX90621 E (-40C to 85C) SF (TO-39) (1) (2) (3) -000 -TU (1) Supply Voltage (2) Number of (3) Package options: B = 2.6V thermopiles: A = 120x25 FOV A = 16X4 B = 60x16 FOV C = reserved D = 40x10 FOV Example: MLX90621ESF-BAB-000-TU Functional diagram General Description The MLX90621 is a fully calibrated 16x4 pixels IR array in an industry standard 4-lead TO-39 package. It Digital Active Thermopile Array contains 2 chips in one package: the MLX90670 (IR array with signal conditioning electronics) and the 24AA02 (256x8 EEPROM) chip. The MLX90621 contains 64 IR pixels with dedicated Digital filtering low noise chopper stabilized amplifier and fast ADC integrated. A PTAT (Proportional To Absolute RAM memory Temperature) sensor is integrated to measure the ambient temperature of the chip. The outputs of both VDD EEPROM I2C interface IR and PTAT sensors are stored in internal RAM and 2 are accessible through I C. VSS CLK SDA 39001090621 Page 1 of 44 Datasheet IR16x4 Rev 3.0 15 September 2016 MLX90621 16x4 IR array Datasheet General Description (continued) The results of the infrared sensor measurements are stored in RAM: 15...18-bit result of IR measurement for each individual sensor (64 words) 1518-bit result of PTAT sensor Depending on the application, the external microcontroller can read the different RAM data and, based on the calibration data stored in the EEPROM memory, compensate for difference between sensors to build up a thermal image, or calculate the temperature at each spot of the imaged scene. These constants are accessible by the user microcontroller through the I2C bus and have to be used for external post processing of the thermal data. This post processing includes: Ta calculation Pixel offset cancelling Pixel to pixel sensitivity difference compensation Object emissivity compensation Object temperature calculation The result is an image with NETD better than 0.1K RMS at 1Hz refresh rate. The refresh rate of the array is programmable by means of register settings or directly via I2C command. Changes of the refresh rate have a direct impact on the integration time and noise bandwidth (faster refresh rate means higher noise level). The frame rate is programmable in the range 0.5Hz512Hz and can be changed to achieve the desired trade-off between speed and accuracy. The MLX90621 requires a single 2.6V3.2V although the device is calibrated and performs best at VDD=2.6V. The MLX90621 is factory calibrated in following temperature ranges: -40C85C for the ambient temperature sensor -50C300C for the object temperature. NOTE: The sensor can detect higher temperatures, but is not calibrated for temperatures above 300C. See Table 21 for configuration specific properties. Each pixel of the array measures the average temperature of all objects in its own Field Of View (called nFOV). It is very important for the application designer to understand that the accuracy of the temperature measurement is very sensitive to the thermal equilibrium isothermal conditions (there are no temperature differences across the sensor package). The accuracy of the thermometer can be influenced by temperature differences in the package induced by causes like (among others): Hot electronics behind the sensor, heaters/coolers behind or beside the sensor or by a hot/cold object very close to the sensor that not only heats the sensing element in the thermometer but also the thermometer package. 39001090621 Page 2 of 44 Datasheet IR16x4 Rev 3.0 15 September 2016