How to Use 74HC4067: Examples, Pinouts, and Specs

The 74HC4067 is a high-speed CMOS 16-channel analog multiplexer/demultiplexer manufactured by Nexperia. It allows one of 16 input/output channels to be connected to a single common terminal, controlled by a 4-bit binary address. This versatile component is widely used in applications requiring signal routing, such as data acquisition systems, sensor arrays, and audio signal switching.

• Signal multiplexing in microcontroller-based systems
• Sensor data acquisition
• Audio signal routing
• Expanding the number of analog inputs for microcontrollers
• Digital-to-analog and analog-to-digital conversion systems

The following table outlines the key technical details of the 74HC4067:

The 74HC4067 has 24 pins, with the following configuration:

The 74HC4067 is straightforward to use in both analog and digital circuits. Below are the steps and considerations for proper usage:

1. Power Supply: Connect the VCC pin to a voltage source (2V to 6V) and the VEE pin to ground (0V) for single-supply operation.
2. Enable Pin: The E (EN) pin must be set LOW to enable the multiplexer. If set HIGH, all channels are disconnected.
3. Channel Selection: Use the S0-S3 pins to select one of the 16 channels. The binary value on these pins determines the active channel:
   • Example: S3 S2 S1 S0 = 0000 selects channel Y0, and 1111 selects channel Y15.
4. Signal Connections: Connect the signals to the Y0-Y15 pins. The selected channel will be routed to the Z pin.

The 74HC4067 can be used with an Arduino UNO to expand the number of analog inputs. Below is an example of how to connect and control the multiplexer:

• Connect VCC to the Arduino's 5V pin and VEE to GND.
• Connect the E (EN) pin to GND to enable the multiplexer.
• Connect the S0-S3 pins to Arduino digital pins (e.g., D2-D5).
• Connect the Z pin to an Arduino analog input (e.g., A0).
• Connect sensors or signals to the Y0-Y15 pins.

// Define control pins for the 74HC4067
const int S0 = 2;  // Address pin S0
const int S1 = 3;  // Address pin S1
const int S2 = 4;  // Address pin S2
const int S3 = 5;  // Address pin S3
const int Z = A0;  // Common terminal connected to Arduino analog pin

void setup() {
  // Set address pins as outputs
  pinMode(S0, OUTPUT);
  pinMode(S1, OUTPUT);
  pinMode(S2, OUTPUT);
  pinMode(S3, OUTPUT);

  // Initialize serial communication for debugging
  Serial.begin(9600);
}

void loop() {
  for (int channel = 0; channel < 16; channel++) {
    // Set the address pins to select the channel
    digitalWrite(S0, channel & 0x01);  // Least significant bit
    digitalWrite(S1, (channel >> 1) & 0x01);
    digitalWrite(S2, (channel >> 2) & 0x01);
    digitalWrite(S3, (channel >> 3) & 0x01);

    // Read the analog value from the selected channel
    int value = analogRead(Z);

    // Print the channel number and value to the serial monitor
    Serial.print("Channel ");
    Serial.print(channel);
    Serial.print(": ");
    Serial.println(value);

    delay(500);  // Wait for 500ms before switching to the next channel
  }
}

• Use decoupling capacitors (e.g., 0.1µF) near the VCC pin to reduce noise.
• Avoid exceeding the voltage and current ratings to prevent damage.
• For high-frequency signals, consider the propagation delay and crosstalk between channels.

1. No Signal on Output (Z) Pin:

   • Ensure the E (EN) pin is LOW to enable the multiplexer.
   • Verify the binary address on the S0-S3 pins matches the desired channel.

2. Incorrect Channel Selection:

   • Check the wiring of the S0-S3 pins to the microcontroller.
   • Ensure the binary address is correctly set in the code or circuit.

3. Signal Distortion:

   • Verify the input signal voltage is within the range of 0V to VCC.
   • Use proper grounding and shielding to minimize noise.

Q: Can the 74HC4067 handle digital signals?
A: Yes, the 74HC4067 can route both analog and digital signals, provided the voltage levels are within the specified range.

Q: What happens if the enable pin is HIGH?
A: When the E (EN) pin is HIGH, all channels are disconnected, and the Z pin is in a high-impedance state.

Q: Can I use the 74HC4067 with a 3.3V microcontroller?
A: Yes, the 74HC4067 operates with supply voltages as low as 2V, making it compatible with 3.3V systems.

Q: Is it possible to cascade multiple 74HC4067 chips?
A: Yes, you can cascade multiple chips to expand the number of channels. Use additional address lines or enable pins to control each chip independently.