(S)urface (Μ)ount (D)evices
It is a very small and lightweight chip surrounded by epoxy resin.
The SMD LED provide high brightness, and consumes less energy than an old lamp (Incandescent).
The voltage required for a SMD LED need is about 2-3.6V *, 0.02A-0.03A. It uses very low voltage and current. Power consumption is very low, only equal to about 1 / 8 of the lamp. Under ideal conditions of current, voltage, and temperature, the lifetime of LED SMD can reach up to 100,000 hours.
Two are the popular SMDs type, the 3528 and 5050.
The SMD3528 is inside a package emitting (chip), while the SMD5050 is inside a package of three emission of light. The reason that we said SMD 3528, is the dimension of this chip (35 mm x 28 mm), and power consumption is around (at 12V) * 0.08W/chip. In contrast, SMD 5050 has dimensions (50 mm x 50 mm) and the consumption is around (at 12V) * 0.24W/chip.
* Note: We say 12V but little above say 2-3,6 V per SMD. For this reason, (for example in led strip)we cant to light less than 3 smd led. (12V is for 3smds).