Have you wondered about the actual light source of an LED downlight?
The 2 most popular types of LED downlights are SMD (Surface Mount Diode) and COB (Chip on Board) downlights. They both produce high quality light, have high life expectancy and are extremely efficient.

What is SMD (Surface Mount Diode)?

SMDs are more efficient than COBs because the light source produces higher lumens per watt, which means that they produce more light with a lower wattage.

They produce a wider beam of light which is spread over a greater area. This means that less material is needed for the heat sink, which in turn means that they are more economical. The manufacturing procedure to make them is more expensive as the SMD diodes (LED chips) are machine printed on a PCB board. Most domestic downlights use SMD LED’s. SMD downlights are covered with a frosted reflector which hides the LED chip array, and spreads the light evenly.

What is COB (Chip on Board)?

A Chip On Board LED Downlight consists of a single LED chip, mounted on the downlight, compared to an array of LED’s like an SMD. As the single cluster of LED’s are mounted in one point, they require greater cooling, so a larger heat sink, usually made of aluminium, must be mounted to dissipate the heat. As more material is required to manufacture a COB LED heat sink, this usually increases the cost slightly.

What are the Advantages of Both?

Benefits of COB

COB downlights provide a better light source. It achieves a more focused light and with the use of reflectors, the light beam can be controlled. Chrome reflectors surrounding the diode can be replaced and set at different angles to make the light beam narrower or wider. Due to the narrow beam and with the use of reflectors that are usually clear, COB lights generate crisper and cleaner as there is no frosting on the lenses. which cuts down the clarity of the LED light. Due to the clear lenses, more light can penetrate further which means they perform well in rooms with high ceilings.

Benefits of SMD

SMD downlights produce a wide spread of light. It floods light everywhere which in turn means there is a higher glare. Their wide beam angle means they are suitable for larger rooms like living rooms, bedrooms, kitchens and bathrooms.

How can You Tell the Difference?

SMDs are hidden by a frosted acrylic lens. The face is usually bigger. COBs faces are exposed to show the one chip. In most cases, they are designed to look like traditional dichroic halogen globes.


JD Lighting hopes to have cleared up some of the mystery behind LED downlights. Shop with the safe knowledge that JD Lighting only deals with top quality downlights!

Top Banner Image: Right: Lampada COB Downlight - has an anti-glare lens, it is recessed so that the light source is hidden.
Left: Tradetec Arte SMD Downlight - is an affordable, high lumen output, super-efficient downlight.)