Important parameters of the LED chip

LED chip is a semiconductor light emitting device of the core components (LED lights), the main principle is that the LED light LED chip PN junction. In general, the semiconductor wafer consists of two parts, part of P-type semiconductor, the hole in it dominates the other side is an N-type semiconductor, here is mainly electronic.

Different LED chips, its structure is similar, there are epitaxial with the chip substrate (sapphire substrate, silicon carbide substrate, etc.) and a doped epitaxial semiconductor material and the transparent metal electrode, and the like.

1, the forward current If:

It refers to the forward current value normal light emitting diode when. In actual use should be selected in 0.6 ? IFm following IF.

2, the forward voltage VF:

Parameters given in the table in the operating voltage is given forward current obtained. Generally at IF = 20mA when measured. Light-emitting diode forward voltage VF at 1.4 ~ 3V. When the outside temperature, VF will drop.

3, V-I characteristics:

Relationship between voltage and current of the light-emitting diode in the forward voltage being less than a certain value (called the threshold), the current is very small, not light. When the voltage exceeds a certain value, the forward current increases rapidly with voltage, light.

4, the luminous intensity IV:

Luminous intensity light-emitting diode is usually fingering line (for cylindrical light tube is one whose axis) luminous intensity direction. If the radiation intensity (1/683) W / sr in that direction, the luminous one candela (symbol cd). Due to the small general intensity LED light-emitting diodes, commonly candlelight so luminous intensity (candela, mcd) for the unit.

5, LED light angle: -90 ° - + 90 °

6, the spectral half width grind:

It represents the spectral purity of the arc tube.

7, 1/2 half-value angle and perspective:

1/2 refers to the angle between the intensity values of the luminous intensity is half the axial direction of the light emitting axis (normal) of.

8, the whole shape:

According to convert the solid angle LED light angle, also called plane angle.

9, Perspective:

Refers to the maximum angle of LED light, depending on the viewing angle, different applications, also called light intensity angle.

10, semi-shape:

Method to 0 ° and the maximum value of luminous intensity angle / 2 between. Strictly speaking, is the corresponding value of the angle between the maximum luminous intensity and maximum luminous intensity values / 2. LED packaging technology resulting in maximum emission angle is not normal light intensity value of 0 °, the introduction of the deviation angle refers to the angle of the maximum luminous intensity corresponding to the angle between 0 ° of law.

11, the maximum forward current IFm:

Allows you to add the maximum forward current. Exceed this value can damage the diode.

12, the maximum reverse voltage VRm:

The maximum allowed voltage that is applied in reverse breakdown voltage. Exceeds this value, the light-emitting diode may be breakdown.

13, the working environment topm:

Light-emitting diodes to be working ambient temperature range. Below or above this temperature range, the light-emitting diodes will not work, efficiency is greatly reduced.

14, allowing the power Pm:

Allows you to add to the positive DC voltage across the LED and the current flowing through the maximum value of the product of it. More than this value, LED fever, damage.