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.

Key Features

• 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