silicon photodiodes. Reference data

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

silicon photodiodes. Reference data

Free technical library

Encyclopedia of radio electronics and electrical engineering / Reference materials

Comments on the article

Silicon photodiodes are intended for use as receivers of infrared radiation as part of optical sensors. They are used in photoelectric automation systems, in devices for non-contact temperature measurement, computer and measuring equipment, program-controlled equipment operating at a radiation wavelength in the range of 0,5 ... 1,12 microns. Actually, the receiver of the photodiode is its pn junction. Under the action of radiation, the CVC of the transition changes significantly.

Photodiodes may contain one photosensitive element, two (FD-20-Z0K), four (FD-19KK) and more. The photosensitive field of the FD-246 photodiode is divided into 12 (or 64) elements. This allows the output signal to be captured in a six-bit Gray code. The geometric shape and dimensions of the elements can also be different.

An immersion cone was used as an entrance window for the FD-K-227 photodiode, and a light guide was used for the FD-252 and FD-252-1. The input window of the FD-20 Z0K device does not have a protective transparent "glass".

Photodiodes are produced in a sealed glass-to-metal housing of various designs. The positive terminal of the device is marked either with a dot of a contrasting color on the body, or with a piece of colored PVC tube on the wire terminal. In the absence of labels, a longer output is positive.

The devices operate in two electrical modes - with external bias and without bias. In the first of them, the photodiode provides high current monochromatic sensitivity, in the second - high detectability.

The main dimensions, pinout and spectral characteristics of the sensitivity of silicon photodiodes are shown in fig. 1-23.

Silicon photodiodes

(click to enlarge)

The main technical characteristics of the devices are summarized in Table. 1. Dashes in the table mean that the crossed out parameters of the corresponding device are not standardized according to the specifications.

(click to enlarge)

Basic parameters, their dimensions and definitions (according to GOST 21934-83)

Spectral sensitivity region, µm - wavelength interval of the spectral characteristic, in which the sensitivity of the radiation receiver exceeds 10% of the maximum value.

The wavelength of the maximum spectral sensitivity, µm is the wavelength corresponding to the maximum spectral sensitivity characteristic.

Working voltage. V is a constant voltage applied to the receiver, at which the nominal values of the parameters are provided for long-term operation.

Ramp current, A - current flowing through the radiation receiver at a given voltage on it in the absence of a radiation flux.

Photocurrent (photosignal current), A - current flowing through the receiver at the specified voltage on it, due to the influence of the radiation flux.

Integral current sensitivity, A/lm - the ratio of the photocurrent to the power of the radiation flux (of a given spectral composition) that caused the appearance of the photocurrent.

Sensitivity threshold, W - RMS value of the first harmonic of the modulated measurement stream acting on the receiver with a given spectral distribution, at which the RMS value of the first harmonic of the voltage (current) of the photosignal is equal to the root-mean-square value of the voltage (current) noise in a given band at the modulation frequency of the stream radiation.

Sensitivity threshold in a single frequency band, VgPts (or lmlGHz) - the sensitivity threshold of the radiation receiver, reduced to a single frequency band of the amplifier.

Photoelectric coupling coefficient, % (or rel. units) - the ratio of the voltage (current) value of the photo signal of an unilluminated (non-irradiated) photosensitive element located next to the illuminated (irradiated) to the value of the voltage (current) of the photo signal illuminated (for multi-element radiation detectors).

Detection power, W~' - the reciprocal of the sensitivity threshold.

Flat angle of view (2c), deg. is the angle in the plane normal to the photosensitive element between the directions of incidence of the parallel beam of radiation, at which the voltage (current) of the photosignal of the radiation receiver decreases to a predetermined level.

In table. 1, among others, there is a parameter "time constant of the radiation receiver, s", which is absent in GOST21934-83. In the departmental normal, this parameter is defined as the time from the beginning of the impact on the photodetector of a rectangular pulse of optical radiation until the moment when the voltage of the photosignal reaches a value equal to 1 - 1/e of the maximum value (see the book Aksenenko M. D., Baranochnikova M. Ya, Smolina O. V. Microelectronic photodetectors. - M.: Energoatomizdat, 1984, p. 137).

The time constant t determines the value of the upper limiting frequency of reproduction of the pulse signal that modulates the radiation flux: Fv.rp ° 1/2πt (if t is in seconds, then the frequency Fv.rp is in hertz).

The photodiode FD-9K (Fig. 7, a) is produced in two modifications - with photosensitive element dimensions of 4,4x4,4 mm or 5,6x5,6 mm. The working field of the FD-20-ZZK device (Fig. 15a) is composed of two pairs of photosensitive elements 0,3x1,4 mm and 0,4x1,4 mm in size.

Devices FD-246 are designed in a unified metal case (Fig. 20) with the number of leads corresponding to the number of photosensitive elements. The conclusions of the photodiodes FD-7K, FD-9K, FD-17K, FD-18K, FD-24K are made in the form of flat petals with a hole for soldering conductors. For photodiodes FD-6K, FD-8K, FD-10K, FD-21-KP, FD-23K, FD-25K, FD-26K, FD-27K, FD-28KP, FD-K-155, FD-K- 227, FD-256 flexible, multi-wire leads.

Photodiodes FD-11 (Fig. 8) are produced with both multi-wire flexible and single-wire leads. The photodiodes FDK-1 and FDK-1 in (Fig. 1) have a positive terminal of retinues of two wires. Devices of some types (for example, FD-28KP. Fig. 17, a) have an additional output from the screen housing.

The technological spread zone is shaded on the graphs of spectral characteristics.

Silicon photodiodes are capable of operating within a very wide range of operating parameters. The values of these parameters are presented in Table. 2.

(click to enlarge)

In conclusion, we note that in the process of serial production of devices, many changes and clarifications are made to the technical documentation regarding electrical characteristics and operating modes. Therefore, the above information should be used to pre-select a device of one type or another, after which it is necessary to refer to the specifications for it.

Literature

Aksenenko M. D., Baranochnikov M. L. Receivers of optical radiation. Directory. - M.: Radio and communication, 1987.
Aksenenko M, D., Baranochnikov M. L., Smolin O. V. Microelectronic photodetectors - M .: Energoatomizdat. 1984.
GOST 17772-79. Radiation receivers and receiving semiconductor photoelectric devices

Author: L. Lomakin, Moscow

See other articles Section Reference materials.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

Bacteria in space are becoming more resistant to antibiotics 23.10.2017

In microgravity conditions, bacteria become significantly more resistant to antibiotics, which is facilitated by several mechanisms at once. This conclusion follows from experiments conducted by scientists from the University of Colorado-Boulder.

It has been known for some time that in space the behavior of bacteria changes - in particular, they become more resistant to antibiotics, that is, higher concentrations are required to destroy them. However, the mechanisms underlying this metamorphosis have so far remained a mystery. To find out, Zea and colleagues sent samples of E. coli strains to the International Space Station (ISS), where they were exposed to varying concentrations of the antibiotic gentamicin sulfate.

It turned out that the number of E. coli cells, compared with the control group on Earth, which was in the same conditions (except for gravity, of course), increased 13 times, but their average size decreased by 73%.

The analysis showed what exactly helped E. coli to increase its resistance so dramatically during its stay on the ISS. First, the cell wall and cell membrane became thicker in microgravity. Secondly, the bacteria began to gather more often in dense lumps, in which the outer cells "sacrifice themselves", dying from the antibiotic, thereby helping those in the "center" to survive.

Finally, the third important circumstance is that some bacterial cells have begun to produce membrane molecules (vesicles) that allow them to "communicate" with each other - potentially this allows you to start the process of infection of the body.

All this means that pathogenic strains of bacteria (and E. coli also have them) in space will be many times more dangerous, and it will be much more difficult to treat the infections they cause. Disturbing news for astronauts.

Other interesting news:

▪ HP Z VR Backpack

▪ New image sensor for automotive cameras

▪ 3-atom thick LED for ultra-thin flexible screens

▪ Bananas under threat

▪ iPhone 6 will be assembled by robots

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Application of microcircuits. Article selection

▪ article Politics with a long-range sight. Popular expression

▪ article Who beat off the nose of the Sphinx? Detailed answer

▪ Article Ginseng ordinary. Legends, cultivation, methods of application