LED lighting design common problems and analysis

First, the problems in the application of semiconductor lighting

Heat dissipation

Lack of standards, products are mixed

There are price and design quality issues, and ultimately consumers choose LED lighting, lack of confidence

Semiconductor lighting is very different from traditional lighting in electrical design. Traditional lighting companies need experience/skill accumulation process.

Everyone is optimistic about the market, but there is still no scale.

Features:

By adjusting the high-precision constant current chip to ensure the consistency of LED brightness and chromaticity, we provide standard, customized and reliable high-quality products for downstream customers at the module level;

New and old lighting design manufacturers, not too complicated electrical design, only need to add a traditional constant voltage power supply to work on the simple circuit design, is the fastest and most reliable way;

Solve the large-scale technical and quality problems in the LED lighting market.

Second, the heat dissipation design

The shortest heat is transmitted to the path, reducing the heat transfer resistance;

Increase the mutual conduction area and increase the heat transfer rate;

Reasonable calculation of the design heat dissipation area;

Effective use of heat capacity effects.

Output drive voltage selection:

It is more suitable to drive around 48V when the mains is driven within 20W;

Larger power mains drive output voltage of about 36V is most suitable;

Most of the offline lighting is 12V and 24V.

Features:

Considering the appropriate driving voltage value based on the serial-parallel safety, the voltage value should be unified as much as possible to reduce the power supply design specification cost;

Based on safety regulations, the product design must meet the certification requirements, and the peak value of the flow exceeds 42.4Vac or the DC exceeds 60Vdc;

Considering the technical and quality issues of large-scale processing in the LED lighting market.

Third, the most efficient back-end driver

When the output voltage is around 48V, the constant current efficiency of the low dropout linear constant current device is up to 99%, the constant current accuracy is within ±3%, and is not affected by any peripheral devices; when the output voltage is around 36V, the low dropout linear constant current device The constant current efficiency is up to 98.6%, the constant current accuracy is within ±3%, and is not affected by any peripheral devices; even in the offline lighting part, the lower voltages of 12V and 24V have 96% and 98% efficiency, respectively; The efficiency is equal.

Features: The most efficient drive constant current architecture; the highest precision constant current mode, minimal impact by peripheral devices; simple, convenient and practical.

Fourth, the power consumption of constant current consumption has reached negligible level

At the CYT laboratory in Shenzhen, we have verified that the back-end constant current efficiency reaches 99.99375%, which is completely negligible;

In the future, we will complete this design achievement in one year. More than ten IC design teams will cooperate with powerful power supply manufacturers to complete this goal as soon as possible.

Five, AC-DC design

The development of switching power supply has been the result of many years of accumulation. In the short term, AC-DC direct constant current cannot be broken. Constant voltage and constant current are the relationship between spear and shield. They must be considered separately. The constant current source load regulation rate is 1% (mA). ) / V, can not achieve constant current effect; the more ideas, the higher the cost, and the risk is directly proportional.

Features:

It is most economical to make rational use of existing switching power supply resources;

The combination of constant pressure and constant current technology is inevitable;

Creativity is effective in stable product technology.

Sixth, LED combination packaging is the future development trend

The combined design of the module can effectively reduce the cost of one-time packaging; the distributed package form is beneficial to reduce the heat-dissipation design cost; the domestic aluminum-based PCB board is selected; the optical design is convenient; the power supply design is simplified; the package form is diverse; force.

This is a representative package of Cree, Nichia, Lumileds, and OSRAM. To design a product, first determine which LED package structure to use; next, consider how to adapt to these package forms; there are not many opportunities for us to choose, the optical structure is built on these packages; many of our ideas can not play well .

Lighting design is ever-changing, how can we get rid of this situation?

Eight, modular packaging and constant current technology combined

Designing LED packages at the PCB board level makes it easy and cost-effective; everyone can brainstorm and develop different types of package forms; design products based on power LEDs with integrated constant current technology and light distribution parameters; effectively respond to ever-changing and ever-changing LED lamps need; the power supply part is only powered by the existing traditional switching constant voltage power supply; the product launch speed is improved, the lamp design is simple and practical, the cost is greatly reduced; and the patented containment of the leading edge LED package can be avoided.