Series:	--
Packaging:	Bulk
Part Status:	Obsolete
Voltage - Collector Emitter Breakdown (Max):	35V
Current - Collector (Ic) (Max):	50mA
Current - Dark (Id) (Max):	50nA
Wavelength:	990nm
Viewing Angle:	40°
Power - Max:	200mW
Mounting Type:	Through Hole
Orientation:	Top View
Operating Temperature:	--
Package / Case:	T 1 3/4

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Optical Sensors - Phototransistors

SFH 303 FA-4 Application Field and Working Principle

Phototransistors are solid-state semiconductor devices that respond to a beam of light or other radiant energy, making them useful for a wide range of applications. The SFH 303 FA-4 is a relatively new phototransistor from Siemens, specifically designed for use in light detection and control applications. The SFH 303 FA-4 is a form of an NPN phototransistor, which means that it has a three-layer configuration, with the base (B) layer connected to the emitter (E), and the collector (C) connected to a fixed voltage either directly or through a signal conditioning module. The phototransistor also has built-in hysteresis, which helps to reduce the effects of sudden changes in light conditions and improves the stability of the output current. The SFH 303 FA-4 has a wide range of applications, from light-controlled switching to image analysis. It is commonly used in automated lighting systems, where it is used to detect and respond to changes in the ambient lighting levels. It is also used in smoke detection systems, as its light sensing capability can help detect the presence of smoke particles in the air. The SFH 303 FA-4 also has a wide range of industrial applications, such as controlling robotic movements. The control signal is generated by the phototransistor\'s ability to measure the light intensity of an area, making it a useful tool in controlling precise movements. It can also be used for asset tracking systems, where the phototransistor is used to detect and identify specific objects. The SFH 303 FA-4 boasts a typical saturation voltage of 0.6V and a gain of 10.5. It also has a high response time of 1ms and a wide operating temperature range of -40 to +85°C. Its ability to accurately sense light levels and quickly respond to changes in the ambient light conditions makes it a very reliable and useful phototransistor for a wide range of applications. The working principle of the SFH 303 FA-4 phototransistor is relatively straightforward. It works by absorbing light energy of the correct wavelength (usually infrared or visible light), which is then converted into electrical energy. This energy is then amplified and output to the signal conditioning module (or directly applied to the power rails). The control signal can also be modified by adjusting the integrated hysteresis control, allowing for precise control of light levels. The SFH 303 FA-4 is an efficient phototransistor, able to detect even subtle changes in light levels and quickly respond to them with a control signal. It is commonly used in a wide range of applications, such as light-controlled switching, smoke detection, asset tracking, and robotic movement control, among others. Furthermore, its wide operating temperature range, fast response time, and integrated hysteresis make it a reliable and effective tool for light detection and control applications.

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