# LED 5mm, Blue

> 5mm LED, blue color, for signaling and indicators on panels, equipment and DIY projects. Supply voltage 3-3.4VDC, viewing angle 15-30 degrees, standard easy-to-mount format, stable color for good visibility. Reference 9041.

- Page: https://sigmanortec.ro/en/led-5mm-blue
- Price: 0.30 RON
- Availability: In stock; 1-2 zile
- Reference: 9041 · EAN: 5947064360129
- Category: Electronic components > LEDs, IRs and Optics
- Package (shipping data): 0 kg
- Updated: 2026-10-20
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 03:25 (Europe/Bucharest)

## Description

5mm blue LED for signaling and indicators on panels, equipment and DIY projects, operates at 3-3.4VDC, provides clear illumination with a concentrated beam due to the 15-30 degree viewing angle, has a standard format for easy mounting and stable color for good visibility.
The 5 mm blue-emitting LED is a light diode with leads for through-hole (THT) mounting, used as a status indicator, signal light, or decorative lighting in electronic circuits. It is suitable for control panels, models, microcontroller projects, educational kits, and applications on a breadboard or test board.
The diode has a standard 5 mm package with a blue lens and operates at a forward voltage of 3 - 3.4 VDC, at a typical current of 20 mA. The viewing angle is 15 - 30 degrees, which concentrates the light into a relatively narrow beam and makes the LED easy to see from the front. Since it is a diode, it has polarity and must always be powered through a current-limiting resistor.
Among the main features are the round 5 mm package, the two axial leads for soldering or insertion into a breadboard, the blue lens, and the narrow viewing angle. It is powered with direct current, from a voltage source higher than the LED forward voltage, with a resistor connected in series.
The LED can be driven from the digital outputs of Arduino, ESP32, STM32, or Raspberry Pi boards, through a limiting resistor, taking into account that the forward voltage of the blue LED is close to the 3.3 V logic level.
Specifications:
Supply voltage: 3 - 3.4 VDC
Operating current: 20 mA
Type: 5 mm LED with leads, through-hole mounting
Color: Blue
Viewing angle: 15 - 30 degrees
Dimensions: 5 mm (diameter)
Pinout:
Connector
Pin
Function
Long pin
Anode (+)
Connects to positive, through the limiting resistor.
Short pin
Cathode (-)
Connects to ground (GND). It is located on the side with the flat edge of the package.
Usage:
Identify the LED polarity: the long pin is the anode (+), and the short pin is the cathode (-), located on the side with the flat edge of the package.
Always install a resistor in series with the LED, because without it the current is not limited and the diode can be destroyed.
Calculate the resistor value with the formula R = (Vsupply - VLED) / ILED. For example, for a 5 V supply, a forward voltage of 3.2 V, and a current of 20 mA, the result is approximately 90 ohms, so the next higher standard value, 100 ohms, is chosen.
Connect the anode to positive through the resistor and the cathode to ground, observing polarity.
Do not apply reverse voltage to the LED and do not power it directly from a voltage source without a limiting resistor.
When powered from 3.3 V, the difference from the LED forward voltage is very small, and brightness may be reduced. In this case, use a low-value resistor or power the LED from a higher voltage, controlled through a transistor.
For control from a microcontroller, connect the resistor to a digital pin configured as an output and respect the maximum current allowed for the pin.
When soldering, work quickly and avoid prolonged heating of the pins, so as not to damage the LED package.