Basic Information:

• Type: Parallel Priority Encoder
• Family: 74HC (High-Speed CMOS)
• Function: Converts 8 input lines into a 3-bit binary output, providing priority to the highest-order active input.

Pin Configuration:

• Inputs: A0 to A7 (8 inputs)
• Outputs: Y0, Y1, Y2 (3-bit binary output)

Control Inputs:

• G (Enable): Activates the device.
• A (Active Low): When low, it allows the encoder to function.

Operation:

• The 74HC688 encodes the highest priority active input (from A0 to A7) into a binary output.
• If no inputs are active, the outputs are set to a predefined state (usually all low).

Electrical Characteristics:

• Supply Voltage (Vcc): Typically operates at 2V to 6V.
• High Level Input Voltage (VIH): Minimum value required for a high logic level.
• Low Level Input Voltage (VIL): Maximum value for a low logic level.
• Output High Voltage (VOH): Minimum value for a high output.
• Output Low Voltage (VOL): Maximum value for a low output.