Datasheet

MLX90640 32x24 IR array
Datasheet
Page 50 of 60
REVISION 11 – 3 AUGUST 2018
12.2.
12.2.12.2.
12.2. Noise performance and resolution
Noise performance and resolutionNoise performance and resolution
Noise performance and resolution
There are two bits in the configuration register that allow changing the resolution of the MLX90640 measurements.
Increasing the resolution decreases the quantization noise and improves the overall noise performance.
Measurement conditions for the noise are: To=Ta=25°C
NOTE: Due to the nature of the thermal infrared radiation, it is normal that the noise will decrease for high temperature and
increase for lower temperatures
Figure 19 MLX90640BAx noise vs refresh rate for different device types
Not all pixels have the same noise performance. Because of the optical performance of the integrated lens, it is normal
that the pixels in the corner of the frame are noisier in comparison with the sensors in the middle. The graphs bellow
show the distribution of the noise performance versus the pixel position in the frame (pixel number)
Figure 20 MLX90640BAA noise vs pixel and refresh rate at 1Hz and 2Hz
Figure 21 MLX90640BAA noise vs pixel and refresh rate at 4Hz, 8Hz and 16Hz