Infrared receiving tube is an electronic component widely used in the LED industry, specifically designed to receive and sense infrared light emitted by infrared emitting tubes. They are usually used in conjunction with infrared emission tubes and play an important role in various product equipment. This article will provide a detailed introduction to the classification of infrared receiver tubes, in order to help readers better understand and apply this technology.

1、 Basic principle of infrared receiver tube

The core component of an infrared receiver tube is a PN junction made of a special material, which has undergone significant structural changes compared to ordinary diodes. In order to receive more and a larger area of incident light, the PN junction area is made as large as possible, while the electrode area is minimized. At the same time, the junction depth of the PN junction is very shallow, generally less than 1 micron. The infrared receiving diode operates under reverse voltage, and when there is no light, the reverse current is very small (generally less than 0.1 microampere), which is called dark current; The current generated under normal illumination is called photocurrent.

2、 Classification of Infrared Receiver Tubes

Infrared receiver tubes can be classified into various types based on their working principles and characteristics. The following are the main classification methods:

1. Classified by working principle

(1) PIN type receiving tube

PIN type receiver tube is the most common and commonly used type of infrared receiver tube. It has a simple structure and contains a special PIN diode inside. When infrared radiation reaches the receiving window, the PIN diode in the photosensitive area will generate a current signal. PIN type receiver tubes are suitable for a wide range of infrared applications, such as remote controls and infrared sensors.

(2) Avalanche type receiver tube

Avalanche type receiver tube is an infrared receiver tube that uses avalanche effect. It introduces a reverse bias voltage in the photosensitive region. When the infrared signal is irradiated onto the receiving window, the reverse voltage will cause avalanche amplification effect, thereby increasing the output current. The Avalanche receiver tube has the characteristics of high sensitivity and high signal-to-noise ratio, making it suitable for applications that require high performance and low power consumption.

(3) Phototransistor type receiver tube

The phototransistor receiver tube consists of a photodiode and a bipolar transistor. When infrared radiation reaches the receiving window, the photodiode generates current, which in turn controls the conduction and cutoff of the transistor. Phototransistor type receiver tubes have high amplification factor and low response time, making them suitable for applications that require high signal amplification.

2. Classify by product appearance

Classifying infrared receivers according to their product appearance is more intuitive and diverse, meeting the needs of different electronic device designs.

(1) Circular receiving tube

Circular receiving tube is the most basic and common shape, with a simple design that is easy to install and fix. Due to its compact size, it is often used in small electronic devices such as infrared receiver modules for mobile phones, headphones, and other products. Circular receiving tubes not only have stable receiving performance, but also can achieve efficient infrared reception in limited space.

(2) Square receiving tube

Compared to circular receiving tubes, square receiving tubes have a larger receiving area, thereby improving the sensitivity of infrared reception. This type of receiver tube is commonly used in devices that require high reception performance, such as smart home control systems, security monitoring equipment, etc. The design of the square receiving tube enables it to more fully receive infrared signals from various directions, enhancing the response speed and accuracy of the device.

(3) Special shaped receiving tube

In addition to circular and square shapes, infrared receiver tubes can also be designed into other special shapes such as strips, rectangles, etc. according to actual needs. These special shaped receiving tubes are usually applied in specific situations, such as strip receiving tubes commonly used in scanning infrared sensors, and rectangular receiving tubes may be used in infrared receiving modules of some large equipment.

In summary, there are various classification methods for infrared receivers, each with its unique characteristics and application scenarios. When selecting a suitable infrared receiver tube, it is necessary to comprehensively consider the actual needs and equipment characteristics.