LED (5 mm)Through-hole indicator LED · Kingbright WP7113 family

Light from current: the resistor decides, the colour sets the voltage.

Manufacturer-referenced

Kingbright · WP7113QBC/D

T-1¾ (5 mm)WP7113 product specifications · red DSAF2430 V.13A, green DSAF2427 V.11B, yellow DSAF2443 V.11B, blue DSAG3481 V.18B, white DSAI6407 V.6B

An LED (light-emitting diode) is a diode that gives off light when current flows from its anode to its cathode. Electrons and holes recombine in the junction and release their energy as photons; the semiconductor material sets the colour and, with it, the forward voltage. An LED is driven by current, not by voltage. Above its forward voltage the current rises very steeply, so every LED needs something that limits it, normally a series resistor: R = (supply − Vf) / I. The same resistor gives a red LED about twice the current of a blue one, because blue needs 3.3 V and red only 1.85 V. This page uses the Kingbright WP7113 family of 5 mm (T-1¾) LEDs, one product specification per colour. The longer lead is the anode; the cathode is the shorter lead beside the flat on the flange. The page numbers them 1 = A and 2 = K, as ProTech and the KiCad footprint do.

3D View

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Real View

5 mm through-hole LED with a blue domed lens, a flanged base and two straight leads 2.54 mm apart.

Pinout

LED (5 mm)T-1¾ (5 mm)Top view · flat and short lead = cathode

PCB Footprint

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2Physical pins WP7113QBC/DT-1¾ (5 mm) Manufacturer-referencedKingbright

Pin diagram

Select a pin to explore its connection

Package map

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LED (5 mm)T-1¾ (5 mm)Top view · flat and short lead = cathode

Click a lead or use the arrow keys. Top view · flat and short lead = cathode

PIN A · Anode · long lead

A

Anode (+)

Function

The longer lead. Conventional current enters here when the LED is forward biased.

How to connect

Connect to the supply or a microcontroller pin through the series resistor.

Electrical note

Forward voltage at 20 mA: 1.85 V red, 2.2 V green, 2.0 V yellow, 3.3 V blue and white (typical).

Key specifications

Choose the current first (5–20 mA for an indicator), then the resistor from the supply and the colour’s forward voltage. Without a resistor the current is limited only by the supply and the LED burns out.

Forward voltage1.85–3.3 V typical at 20 mA · red to white

Continuous forward current30 mA maximum · green 25 mA

Reverse voltage5 V maximum · never use it as a rectifier

Junction limit115 °C · green 110 °C

Operating profile

Supply, signals and operating conditions

LED (5 mm) operating profile
Parameter	Value	Conditions / notes
Selected package	T-1¾ (5 mm)	WP7113QBC/D · 2 leads
Anode	Long lead	Cathode: short lead and the flat
Example circuit	5 V · 220 Ω	Red ≈ 14.3 mA, blue ≈ 7.7 mA

Package details

WP7113QBC/D · T-1¾ (5 mm)

Selected package

Selected LED (5 mm) physical package
Property	Details
Manufacturer	Kingbright
Part number	WP7113QBC/D
Package	T-1¾ (5 mm)
Connections	2 pins
Mounting	Through-hole
Lead pitch	2.54 mm
Package code	T-1¾
Thermal reference	RθJ-A 570–610 °C/W on FR4, by colour

Selected family and polarity

Manufacturer scope and page conventions

Manufacturer specifications 6 parameters

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Parameter	Value	Conditions / notes
Reference family	Kingbright WP7113, 5 mm (T-1¾)	One product specification per colour
Parts	WP7113SRC/DU red · SGD green · SYD yellow · QBC/D blue · QWC/D white	One package; the 3D view shows the blue part
Anode	Long lead · pin 1 · pad A	Conventional current enters here
Cathode	Short lead, flat on the flange · pin 2 · pad K	Connect toward ground
Lens	Ø5.0 mm, water clear or diffused by part	Viewing angle 20–30° (2θ½)
Lead spacing	2.54 mm	0.5 mm square leads

Polarity is marked twice: the shorter lead and the flat. Trim the leads only after noting the anode.

The five colours

Typical at 20 mA and 25 °C unless stated

Manufacturer specifications 5 parameters

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Colour	Part	Vf typ / max (V)	IF max (mA)	Peak IF (mA)	PD (mW)	Iv typ (mcd)	λdom (nm)	2θ½ (°)	Chip
Red	WP7113SRC/DU	1.85 / 2.5	30	155	75	1300	640	20	GaAlAs
Green	WP7113SGD	2.2 / 2.5	25	140	62.5	40	568	30	GaP
Yellow	WP7113SYD	2 / 2.5	30	150	75	1200	590	30	AlGaInP
Blue	WP7113QBC/D	3.3 / 4	30	150	120	4500	465	20	InGaN
White	WP7113QWC/D	3.3 / 4	30	150	120	3600	x 0.31, y 0.31	20	InGaN + phosphor

Peak IF: 1/10 duty cycle, 0.1 ms pulse. Luminous intensity ±15 %. ProTech’s LED colour presets take exactly these values.

Absolute maximum ratings

At 25 °C · stress limits, not operating conditions

Manufacturer specifications 7 parameters

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Parameter	Value	Conditions / notes
Continuous forward current	30 mA (green 25 mA)	Derate above about 25 °C to about 5 mA at 85 °C
Peak forward current	140–155 mA by colour	1/10 duty cycle, 0.1 ms pulse
Power dissipation	75 mW red and yellow · 62.5 mW green · 120 mW blue and white	PD at 25 °C
Reverse voltage	5 V	IR ≤ 10 µA red, green, yellow; ≤ 50 µA blue, white
Junction temperature	115 °C (green 110 °C)	Maximum
Operating and storage temperature	−40 to +85 °C	Ambient
Electrostatic discharge (HBM)	3 kV red, yellow · 8 kV green · 250 V blue, white	Handle InGaN parts with ESD care

Exceeding any one of these can damage the LED even if the others are respected.

Electrical and thermal characteristics

Typical unless stated

Manufacturer specifications 6 parameters

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Parameter	Value	Conditions / notes
Forward voltage temperature coefficient	−1.9 to −2 mV/°C red, green, yellow · −3 mV/°C blue, white	Vf falls as the junction heats
Thermal resistance, junction to ambient	580 red · 590 green, yellow · 610 blue · 570 white °C/W	On FR4
Luminous intensity tolerance	±15 %	At 20 mA
Brightness against current	Roughly proportional	Within the rated current; efficiency falls when hot
Reverse current	≤ 10 µA (red, green, yellow) · ≤ 50 µA (blue, white)	VR = 5 V
Self-heating example	26 mW × 580 °C/W ≈ 15 °C rise	Red at 14.3 mA, 1.85 V

Forward voltage spreads between parts of the same colour; never wire LEDs in parallel without a resistor each.

Series resistor from a 5 V pin

R = (5 V − Vf) / I

Manufacturer specifications 9 parameters

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Parameter	Value	Conditions / notes
Red at 20 mA	160 Ω (E24)	(5 − 1.85) / 0.020 = 157.5 Ω, next E24 value above
Green at 20 mA	150 Ω (E24)	(5 − 2.2) / 0.020 = 140 Ω, next E24 value above
Yellow at 20 mA	150 Ω (E24)	(5 − 2) / 0.020 = 150 Ω, next E24 value above
Blue at 20 mA	91 Ω (E24)	(5 − 3.3) / 0.020 = 85 Ω, next E24 value above
White at 20 mA	91 Ω (E24)	(5 − 3.3) / 0.020 = 85 Ω, next E24 value above
Red with 220 Ω	14.3 mA	(5 − 1.85) / 220 Ω, typical Vf
Green with 220 Ω	12.7 mA	(5 − 2.2) / 220 Ω, typical Vf
Yellow with 220 Ω	13.6 mA	(5 − 2) / 220 Ω, typical Vf
Blue and white with 220 Ω	7.7 mA	(5 − 3.3) / 220 Ω, typical Vf

A microcontroller pin drops a little voltage under load, so the measured current is slightly lower (ProTech’s LED example shows 12.9 mA red, 7.2 mA blue).

Package

WP7113QBC/D · T-1¾ (5 mm)

Manufacturer specifications 5 parameters

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Parameter	Value	Conditions / notes
Lens	Ø5.0 mm	Domed epoxy
Flange	Ø5.9 mm, 1.0 mm thick	The flat marks the cathode
Height	8.6 mm	From the flange’s foot to the dome
Leads	0.5 mm square, 2.54 mm apart, 27 mm minimum	Through-hole
Footprint	Pads A and K, 2.54 mm apart	2.032 mm square pads, 1.016 mm drill

Mechanical tolerance ±0.25 mm unless the sheet states otherwise.

Connections by function

Select a pin for its function, connection guidance and electrical notes.

Anode · long lead1 pin

Cathode · flat side1 pin

LED (5 mm) working principle: illustrated functional stages, basic circuit and connections — Select the diagram to read it at full resolution.

How it works

3 stages · Explore one step at a time

Step 1 / 3

Forward bias the junction

With the anode more positive than the cathode by about the forward voltage, electrons and holes cross the junction and recombine.

Step 2 / 3

Recombination makes light

Each recombination releases a photon. The band gap of the chip material sets its energy, and so the colour: GaAlAs red, AlGaInP yellow, GaP green, InGaN blue; white adds a phosphor to a blue chip.

Step 3 / 3

Limit the current

Above Vf the current rises exponentially, so a series resistor (or a constant-current driver) must set it. Brightness follows the current; heat follows current × voltage.

5 V supply through a 220 ohm resistor into the LED anode, cathode to ground; current about 14.3 mA for red and 7.7 mA for blue. — The resistor can sit on either side of the LED; the current is the same.

Connect it, step by step

Follow the component values and pin connections

Choose the current

10–20 mA for a bright indicator, a few mA for a panel light.

Size the resistor

R = (5 V − Vf) / I; take the next E24 value above.

Mind the polarity

Long lead to the resistor side, short lead and flat to ground.

Cutaway of a 5 mm LED: the cathode anvil holds the chip in a reflector cup, a gold bond wire joins it to the anode post, the epoxy lens focuses the light; inset of the PN junction emitting photons. — Functional cutaway; proportions simplified.

Explore the circuit

Select a stage to see its role and connections

Anvil and reflector cup

The larger internal lead, on the cathode side, carries the chip in a small reflector cup.

Bond wire

A fine gold wire connects the top of the chip to the anode post.

Lens

The domed epoxy lens shapes the beam: a narrow lens gives a small viewing angle and a bright centre.

Selected packageT-1¾ (5 mm)WP7113QBC/D

Physical connections2 pinsPackage-specific numbering

Reference collection7 tables38 parameters & pin functions