LED characteristics: current consumption, voltage, power and light output

The times when the LEDs were used only as indicators of switching on devices have long passed. Modern LED devices can completely interchange incandescent lamps in household, industrial and street lamps. This is facilitated by the various characteristics of LEDs, knowing that you can choose the right LED-analog. The use of LEDs, given their basic parameters, opens up an abundance of opportunities in the field of lighting.

LED characteristics: current consumption, voltage, power and light output

What are the LEDs

The LED (denoted by LED, LED, LED in English) is a device based on an artificial semiconductor crystal. By passing an electric current through it, the phenomenon of photon emission is created, which leads to luminescence. This glow has a very narrow range of the spectrum, and its color depends on the semiconductor material.

LED characteristics: current consumption, voltage, power and light output

LEDs with a red and yellow glow are made from inorganic semiconductor materials based on gallium arsenide, green and blue are made on the basis of indium-gallium-nitride. To increase the brightness of the luminous flux, various additives are used or a multilayer method is used when a layer of pure aluminum nitride is placed between the semiconductors. As a result of the formation of several electron-hole (p – n) transitions in one crystal, its luminosity increases.

There are two types of LEDs: for indication and illumination. The first is used to indicate the inclusion of various devices in the network, as well as sources of decorative lighting. They are colored diodes placed in a translucent case, each of them has four leads. Devices emitting infrared light, used in devices for remote control devices (remote control).

In the field of illumination, LEDs emitting white light are used. LEDs are distinguished by color with a cool white, neutral white and a warm white glow. There is a classification used for lighting LEDs by the method of installation. SMD LED marking means that the device consists of an aluminum or copper substrate on which a diode crystal is placed. The substrate itself is located in the housing, the contacts of which are connected to the contacts of the LED.

LED characteristics: current consumption, voltage, power and light output

Another type of LED is indicated by OCB. In such a device on one board is placed a lot of crystals coated with phosphor. Thanks to this design, high luminance is achieved. This technology is used in the manufacture of LED lamps with a high luminous flux in a relatively small area. In turn, this makes the production of LED lamps the most affordable and inexpensive.

Note! Comparing the lamps on SMD and COB LEDs, it can be noted that the first ones can be repaired by replacing a failed LED. If the lamp does not work on the COB LEDs, you will have to change the entire board with diodes.

When choosing a suitable LED lamp for lighting, you should take into account the parameters of the LEDs. These include the supply voltage, power, operating current, efficiency (light output), luminescence temperature (color), radiation angle, dimensions, term of degradation. Knowing the basic parameters, it will be possible to easily choose instruments for obtaining one or another result of illumination.

LED characteristics: current consumption, voltage, power and light output

As a rule, for ordinary LEDs, a current of 0.02A is provided. However, there are LEDs designed for 0.08A. These LEDs include more powerful devices, in which four crystals are involved in the device. They are located in the same building. Since each of the crystals consumes 0.02A, in total, one device will consume 0.08A.

The stability of the LED devices depends on the magnitude of the current. Even a slight increase in current strength contributes to a decrease in the intensity of radiation (aging) of the crystal and an increase in color temperature. This ultimately leads to the fact that the LEDs begin to cast in blue and prematurely fail. And if the indicator of the current intensity increases significantly, the LED will immediately burn out.

In order to limit the current consumption, current-regulators for LEDs (drivers) are provided in LED-lamp and luminaire designs. They convert the current, bringing it to the desired value of the LEDs. In the case when you need to connect a separate LED to the network, you need to use current-limiting resistors. The resistor for the LED is calculated based on its specific characteristics.

Helpful advice! To choose the right resistor, you can use the calculator for calculating the resistor for the LED, located on the Internet.

LED characteristics: current consumption, voltage, power and light output

How to know the voltage of the LEDs? The fact is that the LED voltage parameter as such is not present. Instead, the characteristic of the voltage drop across the LED is used, which means the magnitude of the voltage at the output of the LED when a rated current passes through it. The voltage value indicated on the package reflects the voltage drop. Knowing this value, one can determine the voltage remaining on the crystal. This value is taken into account in the calculations.

Given the use of different semiconductors for LEDs, the voltage at each of them may be different. How to find out how many volts the LED? You can determine the color of the glow devices. For example, for blue, green and white crystals the voltage is about 3V, for yellow and red – from 1.8 to 2.4V.

When using parallel connection of LEDs of identical rating with a voltage of 2V, you may encounter the following: as a result of the variation of parameters, some emitting diodes will fail (burn), while others will glow very faintly. This will happen due to the fact that with an increase in the voltage even by 0.1V, an increase in the current passing through the LED is observed by a factor of 1.5. Therefore, it is important to ensure that the current corresponds to the rated LED.

LED characteristics: current consumption, voltage, power and light output

Comparison of the luminous flux of the diodes with other light sources is carried out, given the strength of the radiation they emit. Instruments measuring about 5 mm in diameter produce from 1 to 5 lm of light. While the luminous flux of an incandescent lamp of 100W is 1000 lm. But when comparing it is necessary to take into account that the light of the ordinary lamp is diffused, while that of the LED is directional. Therefore, it is necessary to take into account the angle of dispersion of the LEDs.

The scattering angle of different LEDs can be from 20 to 120 degrees. When illuminated, the LEDs give a brighter light in the center and reduce illumination to the edges of the scattering angle. Thus, LEDs illuminate a particular space better, while using less power. However, if you want to increase the area of ​​illumination in the design of the lamp using diffusing lenses.

How to determine the power of LEDs? To determine the power of the LED lamp required to replace the incandescent lamp, you need to apply a factor of 8. So, you can replace an ordinary 100W lamp with an LED device with a minimum power of 12.5W (100W / 8). For convenience, you can use the data of the table of correspondence between the power of incandescent lamps and LED-light sources:

Incandescent lamp power, W Corresponding power of the LED lamp, W
100 12-12,5
75 ten
60 7.5-8
40 five
25 3


When using LEDs for lighting is very important indicator of efficiency, which is determined by the ratio of the luminous flux (lm) to power (W). Comparing these parameters with different light sources, we find that the efficiency of an incandescent lamp is 10-12 lm / W, fluorescent – 35-40 lm / W, LED – 130-140 lm / W.

LED color temperature sources

One of the important parameters of LED sources is the temperature of the glow. The units of this magnitude are Kelvin degrees (K). It should be noted that according to the luminescence temperature, all light sources are divided into three classes, among which warm white has a color temperature of less than 3300 K, day white is from 3300 to 5300 K and cold white is over 5300 K.

Note! Comfortable perception by the human eye of LED radiation is directly dependent on the color temperature of the LED source.

Color temperature is usually indicated on the marking of LED lamps. It is indicated by a four-digit number and the letter K. The choice of LED-lamps with a specific color temperature depends on the characteristics of its use for lighting. The table below shows the use of LED sources with different luminous temperatures:

LED color Color temperature, K Lighting Uses
White Warm 2700-3500 Lighting of household and office space as the most appropriate analogue of an incandescent lamp
Neutral (daily) 3500-5300 Excellent color rendition of such lamps allows them to be used to illuminate workplaces in production
Cold over 5300 Used mainly for street lighting, as well as used in the device of hand lamps.
Red 1800 As a source of decorative and phyto-lighting
Green Illumination of surfaces in the interior, phyto-lighting
Yellow 3300 Light design of interiors
Blue 7500 Illumination of surfaces in the interior, phyto-lighting


The wave nature of the color allows the color temperature of the LEDs to be expressed using the wavelength. Marking some LED devices reflects the color temperature in the form of an interval of different wavelengths. Wavelength is designated? and is measured in nanometers (nm).

Standard sizes of SMD LEDs and their characteristics

Given the size of SMD LEDs, devices are classified into groups with different characteristics. The most popular LEDs with frame sizes are 3528, 5050, 5730, 2835, 3014 and 5630. The characteristics of SMD LEDs vary depending on the size. So, different types of SMD LEDs differ in brightness, color temperature, power. In the marking of LEDs, the first two digits indicate the length and width of the device.

LED characteristics: current consumption, voltage, power and light output

The main parameters of SMD 2835 LEDs

The main characteristics of SMD LEDs 2835 include an increased radiation area. In comparison with the SMD 3528 device, which has a round working surface, the radiation area of ​​the SMD 2835 has a rectangular shape, which contributes to greater light output with a lower element height (about 0.8 mm). The luminous flux of such a device is 50 lm.

The housing of the SMD 2835 LEDs is made of heat-resistant polymer and can withstand temperatures up to 240 ° C. It should be noted that the degradation of radiation in these elements is less than 5% during 3000 hours of operation. In addition, the device has a rather low thermal resistance of the crystal-substrate transition (4 C / W). The maximum operating current is 0.18A, the crystal temperature is 130 ° C.

By the color of the glow, warm white is emitted with a luminescence temperature of 4000 K, daytime white is 4800 K, pure white is from 5000 to 5800 K and cold white with a color temperature of 6500-7500 K. a luminescence, minimum – at light-emitting diodes of warm white color. The design of the device increased contact pads, which contributes to a better heat dissipation.

Helpful advice! SMD 2835 LEDs can be used for any type of installation.

LED characteristics: current consumption, voltage, power and light output

SMD 5050 LED Characteristics

The design of the SMD 5050 housing contains three of the same type of LED. LED sources of blue, red and green have technical characteristics similar to those of SMD 3528 crystals. The operating current value of each of the three LEDs is 0.02A, hence the total current value of the entire device is 0.06A. In order for the LEDs not to fail, it is recommended not to exceed this value.

SMD 5050 LED devices have a direct voltage of 3-3.3V and light output (mains flow) 18-21 lm. The power of one LED consists of three values ​​of the power of each crystal (0.7W) and is 0.21W. The color of the glow emitted by the devices can be white in all shades, green, blue, yellow and multicolor.

The proximity of the LEDs of different colors in one SMD 5050 package allowed for multi-color LEDs with separate control of each color. For regulating luminaires using SMD 5050 LEDs, controllers are used, so that the luminescence color can be smoothly changed from one to another after a specified amount of time. Typically, such devices have several control modes and can adjust the brightness of the LEDs.

LED characteristics: current consumption, voltage, power and light output

Typical SMD 5730 LED Characteristics

The SMD 5730 LEDs are modern representatives of LED devices, the casing of which has geometrical dimensions of 5.7×3 mm. They belong to the high-brightness LEDs, whose characteristics are stable and qualitatively different from the parameters of the predecessors. Made with the use of new materials, these LEDs are characterized by increased power and highly efficient luminous flux. In addition, they can work in conditions of high humidity, are resistant to temperature and vibration, have a long service life.

There are two types of devices: SMD 5730-0.5 with a power of 0.5W and SMD 5730-1 with a power of 1W. A distinctive feature of the devices is the possibility of their operation on a pulse current. The value of the nominal current SMD 5730-0.5 is 0.15A, with pulse operation, the device can withstand a current of up to 0.18A. This type of LED provides a luminous flux of up to 45 lm.

The SMD 5730-1 LEDs operate at a constant current of 0.35 A, and in the pulsed mode, up to 0.8 A. The luminous efficiency of such a device can be up to 110 lm. Due to the heat-resistant polymer, the instrument case withstands temperatures up to 250 ° C. The scattering angle of both types of SMD 5730 is 120 degrees. The degree of degradation of the luminous flux is less than 1% when working for 3000 hours.

LED characteristics: current consumption, voltage, power and light output

Cree LED Characteristics

The company Cree (USA) is engaged in the development and production of super-bright and the most powerful LEDs. One of the groups of Cree LEDs is represented by a series of Xlamp devices, which are divided into single-chip and multichip. One of the features of single-chip sources is the distribution of radiation at the edges of the device. This innovation made it possible to produce lamps with a large angle of illumination, using a minimum amount of crystals.

In the XQ-E High Intensity LED Sources Series, the luminous angle ranges from 100 to 145 degrees. Having a small geometric dimensions of 1.6 x1.6 mm, the power of high-brightness LEDs – 3 volts, and the luminous flux – 330 lm. This is one of the newest developments by Cree. All LEDs, the design of which is developed on the basis of a single crystal, have high-quality color reproduction within the CRE 70-90.

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