Photodiode SFH 2440 L from Osram Opto Semiconductors saves on mounting height in the design of heart rate sensors. It can be flush-mounted on the printed circuit board (PCB), with longer leads ensuring secure mounting and reliable solder points. The component also features spectral sensitivity specially designed for measuring heart rate.
- SFH 2440 L is a large-area photodiode and good at registering visible wavelengths, whereas most of the infrared light is suppressed by a filter
- To achieve the best signal-to-noise ratio, the bandpass filter in the SFH 2440 and the SFH 2440 L cuts off wavelengths above the visible spectral range
- In the infrared range the relative sensitivity is only five percent of the maximum value at 620 nanometers
- Sensitivity for green light is very high so good signal quality can be achieved for pulse measurements with green light even at a low operating current
- Photodiode offers short switching times of 90 nanoseconds so the detector signals modulated with the heart rate can be resolved with a high level of precision
Filed Under: Materials • advanced