4×5 Matrix 20-Key Membrane Switch Keypad with Ribbon Cable

4×5 Matrix 20-Key Membrane Switch Keypad with Ribbon Cable is an expanded alphanumeric membrane keyboard featuring 20 distinct keys organized in a 4-row by 5-column matrix. Equipped with numeric digits 0-9, letters A-D, specialized function keys (F1, F2), and symbols (* and #), it provides an expansive, sealed human-machine interface for complex menu control and numeric data entry in microcontroller projects.

Key Features:

• Expanded 20-Key Alphanumeric Layout: Includes numbers 0-9, functions A, B, C, D, F1, F2, *, and #.
• Matrix Scanning Economy: Controls 20 individual switches using only 9 microcontroller I/O pins (4 rows and 5 columns).
• Tactile Click Membrane: Metal dome switches underneath each key provide crisp tactile feedback upon actuation.
• Self-Adhesive Mounting: Peel-away 3M adhesive backing permits flat flush mounting on cabinets and front panels.
• Sealed Moisture-Proof Surface: Sealed polyester film overlay protects circuits against dust, dirt, and moisture.
• Standard DuPont Ribbon: 9-pin 2.54mm pitch female DuPont connector mates with standard header pins.

Technical Specifications:

• Maximum Circuit Voltage: 35V DC, 100 mA
• Contact Resistance: 10 Ω to 500 Ω
• Insulation Resistance: 100 MΩ at 100V DC
• Contact Bounce: < 5 ms
• Lifespan: Over 1,000,000 actuations per key
• Operating Temperature: -20°C to +50°C

Mechanical Specifications:

• Keypad Structure: Sealed flexible polyester membrane with internal metal domes
• Connector: 9-Pin 2.54mm pitch female DuPont connector
• Tail Cable Length: Approximately 90 mm
• Weight: Approximately 11 grams

Dimensions:

• Keypad Width: 75.0 mm
• Keypad Height: 85.0 mm
• Thickness: 0.8 mm

Pinout and Wiring:

• Pins 1 to 4: Rows 1, 2, 3, 4
• Pins 5 to 9: Columns 1, 2, 3, 4, 5

Datasheet Reference:

• Datasheet Reference: Consult standard 4×5 matrix scanning documentation and Arduino Keypad.h customization examples.

Commonly Used in:

• Advanced industrial machinery parameter programming consoles
• Point-of-sale terminals and automated dispensing systems
• Security vaults and multi-tier access control systems
• Medical and scientific laboratory input devices

Applications:

• Alphanumeric and function key navigation on graphical LCDs
• POS register and inventory terminal prototyping
• High-security multi-character passcode authentication
• Custom embedded computing interface panels

Equivalent Models:

• 4×4 Membrane Switch Keypad
• 4×3 Matrix Keypad Module
• TTP229 16-Channel Touch Keypad

Package Includes:

• 1 × 4×5 Matrix 20-Key Membrane Switch Keypad with Ribbon Cable