How to Use 4511: Examples, Pinouts, and Specs

The 4511 BCD to 7-segment latch/decoder/driver is an integrated circuit that converts binary-coded decimal (BCD) input data into signals required to drive a 7-segment display. This component is widely used in digital clocks, electronic meters, and other devices that display numerical information.

• Digital clocks and timers
• Electronic counters
• Calculators
• Instrumentation displays

• Supply Voltage (Vcc): 3V to 18V
• Input Voltage (Vi): -0.5V to Vcc+0.5V
• Output Voltage (Vo): -0.5V to Vcc+0.5V
• Operating Temperature: -55°C to +125°C
• Output Current: 25mA per segment

1. Connect Vcc to a power supply within the specified range (3V to 18V).
2. Connect GND to the ground of the power supply.
3. Apply BCD inputs (A, B, C, D) to the corresponding pins.
4. Connect the outputs (a-g) to the segments of a 7-segment display with appropriate current-limiting resistors.
5. Use the LE pin to latch the input data. When LE is high, the output will follow the input data.
6. The BI pin can be used to turn off all segments when pulled low.
7. The LT pin can be used to turn on all segments for testing purposes when pulled low.

• Always use current-limiting resistors with the segment outputs to prevent damage to the IC and the display.
• Avoid applying voltages higher than Vcc+0.5V to the input pins to prevent damage.
• Ensure that unused input pins are tied to an appropriate logic level (high or low).

• Display not lighting up: Check if the power supply is within the specified range and properly connected to Vcc and GND.
• Incorrect display output: Verify that the BCD inputs are correctly applied and that the LE pin is being used properly.
• Segments are dim: Ensure that the current-limiting resistors are of the correct value for the chosen supply voltage.

• Double-check wiring and connections for any loose or incorrect connections.
• Use a multimeter to verify the voltage levels at the power supply and the input pins.
• If a segment is not lighting up, check the corresponding output pin and segment for continuity.

// Define the pins connected to the 4511 inputs
const int pinA = 2;
const int pinB = 3;
const int pinC = 4;
const int pinD = 5;

void setup() {
  // Set the pins as outputs
  pinMode(pinA, OUTPUT);
  pinMode(pinB, OUTPUT);
  pinMode(pinC, OUTPUT);
  pinMode(pinD, OUTPUT);
}

void loop() {
  // Loop through the digits 0 to 9
  for (int number = 0; number < 10; number++) {
    // Convert the number to BCD and output it
    displayBCD(number);
    delay(1000); // Wait for 1 second
  }
}

void displayBCD(int number) {
  // Use bitwise operations to set the BCD pins
  digitalWrite(pinA, number & 1);
  digitalWrite(pinB, number & 2);
  digitalWrite(pinC, number & 4);
  digitalWrite(pinD, number & 8);
}

This example demonstrates how to cycle through the numbers 0 to 9 on a 7-segment display connected to a 4511 BCD to 7-segment decoder. The displayBCD function takes an integer and sets the appropriate BCD pins on the 4511 to display the corresponding number on the 7-segment display.