3MM LEDs - 25 Pieces

Specifications:

BF0993-02 - Blue

Color Frequency: 460-465nm
Luminous Intensity: 1,800mcd
Viewing Angle: Diffused Lens
Forward Voltage: 2.9v - 3.2v
Typical Voltage: 3.1v
Typical Forward Current: 18mA
Style: Round 3mm
Lens: Frosted

RF0993-02 - Red

Color Frequency: 620-628nm
Luminous Intensity: 3,600mcd
Viewing Angle: Diffused Lens
Forward Voltage: 1.9v - 2.1v
Typical Voltage: 2.0v
Typical Forward Current: 18mA
Style: Round 3mm
Lens: Frosted

YF0993-02 - Yellow

Color Frequency: 590-595nm
Luminous Intensity: 4,000mcd
Viewing Angle: Diffused Lens
Forward Voltage: 1.9v - 2.1v
Typical Voltage: 2.0v
Typical Forward Current: 18mA
Style: Round 3mm
Lens: Frosted

GF0993-02 - Green

Color Frequency: 515-525nm
Luminous Intensity: 2,900mcd
Viewing Angle: Diffused Lens
Forward Voltage: 2.2v - 2.4v
Typical Voltage: 2.3v
Typical Forward Current: 18mA
Style: Round 3mm
Lens: Frosted

LED Series Dropping Resistor

Each light emitting diode (LED) has an optimal and maximum current which they can safely handle. Going beyond that maximum current, even briefly, may damage the LED internally without any visible signs. The damage can include reduced intensity, inconsistent power requirements, heating, or shortened useful life. Thus, limiting the current through the LED with the use of a series resistor is a necessary and straightforward practice.

The chart below lists LED models along with the supply voltages. From there, determine the value of the Series Dropping Resistor. The last column (3.3v @ 8mA) lists the dropping resistor value necessary for low-current operation (less than 8mA) for 3.3V applications (like NodeMCU logic pins).