7 segment LED Display 0.8-inch Common Cathode

The 0.8-inch 7 Segment LED Display (Common Cathode) is one of the most fundamental and widely used display components in electronics, used to visually represent numeric digits (0–9) and a limited set of alphabetic characters (A, b, C, d, E, F) in a clear and easily readable format. The display consists of seven individual LED segments arranged in a figure-eight pattern—labeled a through g—plus an additional decimal point (DP) LED, making a total of eight controllable segments. By selectively illuminating different combinations of these segments, any digit from 0 to 9 or certain letters can be displayed. In the common cathode configuration, all the cathodes (negative terminals) of the LEDs are connected together internally to a single common pin that is tied to ground (GND), while each anode (positive terminal) is individually accessible. To light up a specific segment, you apply a HIGH signal (with a current-limiting resistor) to its corresponding anode pin. This makes the common cathode type particularly well-suited for direct driving from microcontroller GPIO pins like those on Arduino, PIC, AVR, or Raspberry Pi. With a display height of 0.8 inches (~20mm), the digit is large enough to be clearly visible from a distance, making it ideal for panel-mounted displays, clocks, counters, and digital meters. The bright red LED color is the most common and offers excellent visibility in both indoor and moderately lit outdoor environments.

Specifications

• Display Type: Single-Digit 7 Segment LED Display
• Configuration: Common Cathode (CC)
• Digit Height: 0.8 inch (~20 mm)
• Color: Bright Red (most common variant)
• Number of Segments: 7 + Decimal Point (DP) = 8 LEDs
• Pin Count: 10 pins (typical)
• Forward Voltage per Segment: 1.8V – 2.2V
• Forward Current per Segment: 10 mA – 20 mA (typical)
• Peak Forward Current: Up to 30 mA
• Reverse Voltage: 5V
• Luminous Intensity: Varies by segment (typically bright enough for indoor use)
• Viewing Angle: Approximately 120°
• Wavelength (Red): 625 nm
• Operating Temperature: -25°C to +85°C
• Storage Temperature: -40°C to +100°C
• Physical Dimensions: 20.3 mm × 13.0 mm × 6.0 mm (L × W × H)
• Weight: 10 grams (approximately)
• Package Type: Through-hole DIP style
• Lifespan: 50,000 – 100,000 hours (typical)

Segment Layout

• Segment a: Top horizontal bar
• Segment b: Upper right vertical bar
• Segment c: Lower right vertical bar
• Segment d: Bottom horizontal bar
• Segment e: Lower left vertical bar
• Segment f: Upper left vertical bar
• Segment g: Middle horizontal bar
• DP: Decimal point (usually bottom right)

Applications

• Used in digital clocks and time display devices.
• Essential in digital counters for events and production lines.
• Employed in electronic scoreboards for sports and games.
• Used in digital thermometers to display temperature readings.
• Applied in digital voltmeters and ammeters for measurement devices.
• Common in Arduino and microcontroller projects for numeric output.
• Used in countdown timers and stopwatches.
• Found in home appliance displays like microwaves and ovens.
• Employed in industrial control panels for status indication.
• Used in price displays in retail and vending machines.
• Applied in elevator floor indicators and status panels.
• Common in calculator displays and basic math tools.
• Used in DIY electronic games and educational kits.
• Found in parking meters and ticket machines.
• Employed in weight scales and measurement tools.
• Used in car dashboards for digital readouts.
• Applied in currency counters and banking equipment.
• Common in RPM meters and speed indicators.
• Used in frequency counters and signal generators.
• Found in ATMs and POS systems.