16 Key Encoder 74922

The 16 Key Encoder 74922 is the 74C922 (MM74C922) CMOS keypad encoder IC. It scans a 4 × 4 matrix of up to 16 switches, removes key bounce and gives the pressed key as a 4-bit binary code, with a Data Available output that goes high when a valid key is pressed. It lets a microcontroller or logic circuit read a full keypad using only a few pins.

16 Key Encoder 74922 Specifications

• Part: 74C922 / MM74C922 16-key encoder
• Logic family: CMOS
• Supply voltage: 3 V to 15 V
• Keypad interface: 4 row inputs with on-chip pull-ups and 4 column scan outputs for a 4 × 4 keypad, no diodes needed
• Outputs: 4-bit binary code (A–D), three-state and LPTTL compatible, plus Data Available (DA)
• Features: key debounce with a single external capacitor, two-key roll-over, last key held in an internal register
• Clock: set by an external capacitor or an external clock
• Pins: 18

16 Key Encoder 74922 Applications

• Reading 4 × 4 membrane keypads with Arduino, PIC or 8051 microcontrollers
• Keypad entry for door locks, calculators and control panels
• Digital logic labs and university projects
• Saving microcontroller pins and processing time on keypad scanning

What's in the Box

• 1 × 74C922 16-key encoder IC

Tip: Fit the capacitors on the OSC and KBM pins as shown in the datasheet, and tie the Output Enable pin low (it is active low) to enable the outputs. Use the Data Available pin as an interrupt so your microcontroller reads the code only when a key is pressed.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.