6 requirements of LED lamps for low voltage drive IC

LED lamps use LED light source has small power (IF 15~20mA) and high power (IF greater than 200mA) two kinds. Small power LED multi use to make LED fluorescent lamp, decorative lamp, grille lamp. High power LED is used to do household lighting, spotlights, underwater lights, wall lights, street lights, tunnel lights, car lights, etc..

Lighting with LED light source VF voltage are very low, usually 2.75~3.8V, IF is generally 15~1400mA. Thus, the output voltage of the LED drive IC is VFxN or VFx1, and the IF maintains a constant current at 15~1400mA. The power LED light source is a low voltage and high current driving device, and its luminous intensity is determined by the current flowing through the LED. The current is too large to cause LED light attenuation, the current is too small will affect the luminous intensity of LED. Therefore, the LED driver needs to provide a constant current power supply to ensure the safety of the use of high-power LED, while achieving the desired luminous intensity.

In the field of LED lighting, in order to reflect the LED lamp energy saving and long life characteristics, the correct choice of LED driver IC is essential. There is no good driver IC match, the advantages of LED lighting can not be reflected.

6 requirements of LED lamps for low voltage drive IC

Requirements of LED lamps for low voltage drive ic:

1, the nominal input voltage range of the driver chip should meet the DC 8~40V to cover a wide range of applications.

Pressure capacity is better than 45V. When the input is AC 12V or 24V, the simple bridge rectifier output voltage will fluctuate with the grid voltage, especially when the voltage is high, the output DC voltage will be higher. If the drive IC does not have a wide input voltage range, often in the grid voltage will be breakdown, thus burning LED light source.

2, the nominal output current of the driving chip is greater than 1.2~1.5A.

As the LED light source for illumination, the nominal operating current of the 1W power LED light source is 350mA, and the nominal operating current of the 3W power LED light source is 700mA. Need high-power LED light source more current, thus driving the IC LED lighting used must have enough current output, the design of products should also be made to drive IC at full load output of the 70~90%'s best work area. The use of full load output current drive IC in the narrow space of the lamp is not smooth, easily lead to fatigue and early failure of the lamp.

3, the output current of the driver chip must be kept constant, so that LED can be stable and not blinking.

Under the same conditions, the same driver chip, the output current to the same size as possible, that is to say, the discreteness is small, so in the production of large quantities of automated production line to ensure effective and orderly. A discrete driving chip to output current, required the classified pick in the factory or put into production line, adjust the PCB board current setting resistor size, LED lamps to produce constant current drive in the brightness of the similar LED light source, in order to maintain the consistency of the final product.

4, the driver chip packaging should be conducive to the rapid cooling of the chip core.

If the bare chip is directly bound to the copper plate, and a pin extends directly to the package, in order to facilitate direct welding on the PCB board copper foil. If the 4x4mm chip on a long time through the 300~1000mA current, it is necessary to generate power consumption and heat, therefore, the chip itself is also very important physical heat dissipation structure.

5, the ability to drive chip EMI, noise and high pressure resistance is also related to the entire LED lighting products can successfully passed CE, UL certification.

Therefore, in the design of the drive chip, we must use advanced topology and high pressure production process.

6, the power consumption requirements of the driver chip is less than 0.5W, the switching frequency is greater than 120Hz, so as to avoid the occurrence of visible flicker.

In short, LED green lighting to drive the chip to the development of innovative design. LED lighting can not be separated from the driver chip, so the need for multi-functional LED light source driver IC. If the LED lamps and lanterns choose the following 36V AC power supply, can consider non isolated power supply; if the choice of 220V and 100V AC power supply, should be considered isolated power supply. Direct use of AC 100~220V driver chip, due to the application of the demanding requirements of the volume, there is a higher technical requirements, greater difficulty, the country is trying to develop. The mass market demand of LED lamps to all Integrated Circuit Design Company again if the chance of success, rapid transformation, early products, is the chance to win a lot of.