First Sensor WS PD Data Sheet First Sensor WS PD Data Sheet
Part Description WS7.56 TO Part Description WS7.56 TO
Order # 501224; 501225 Order # 501224; 501225
Version 15-11-11 Version 15-11-11
Quantum efficiency (23 °C) Dark current as of bias (23 °C)
Special charactertistics:
• Soldering temperature max. 260 °C for 10 s. The device must be protected against solder flux vapour.
• Minimum pin length is 2 mm.
• For ESD protection standard precautionary measures are sufficient.
• For further questions please refer to document "Instructions for handling and processing".
European, International Sales:
sales.opto@first-sensor.com sales.us@first-sensor.com
The WS7.56 wavelength sensor has two p-n junctions constructed vertically on a common
silicon substrate.
The upper and lower diode have an enhanced blue and red response, respectively. Absorbed
radiation between 450 and 900 nm generates two photocurrents proportional to the
wavelength of the incident light. The quotient of the signals is independent of light level up to
the saturation point. The wavelength of monochromatic light or the spectral density peak of
polychromatic light can therefore be determined.
During photovoltaic operation (Vrev= 0 V) the quotient of photocurrents
from anode 1 and anode 2 is constant for up to 150 µW irradiated
power. This range can be increased to up to 3mW when the reverse
bias is raised. A recomended application circuit is shown to the right.
0
20
40
60
80
400 450 500 550 600 650 700 750 800 850 900 950 1000
0,01
0,10
1,00
10,00
0 1 2 3 4 5