How to Use 4047 ic : Examples, Pinouts, and Specs

The 4047 IC is a versatile integrated circuit designed to operate as an astable multivibrator, monostable multivibrator, or Schmitt trigger. It is widely used in applications requiring precise timing, frequency generation, and pulse-width modulation. Its ability to operate in both monostable and astable modes makes it a popular choice for circuits such as oscillators, timers, and signal generators.

• Frequency generation for oscillators
• Pulse-width modulation (PWM) circuits
• Timer circuits (monostable mode)
• LED and lamp flashers
• Clock pulse generation
• Square wave generation

The 4047 IC is a CMOS-based device with low power consumption and high noise immunity. Below are its key technical details:

• Supply Voltage (Vcc): 3V to 15V
• Operating Current: 10 µA (typical at 5V)
• Output Current: 3.2 mA (maximum at 5V)
• Frequency Range (Astable Mode): Up to 1 MHz
• Temperature Range: -40°C to +85°C
• Logic Compatibility: CMOS and TTL
• Package Types: DIP-14, SOIC-14

The 4047 IC comes in a 14-pin package. Below is the pinout and description:

The 4047 IC can be configured in two primary modes: astable and monostable. Below are the steps to use the IC in each mode:

• Connect a resistor between Pin 1 and Pin 2, and a capacitor between Pin 2 and GND.
• Set Pin 3 (A/!M) to logic HIGH to enable astable mode.
• The frequency of oscillation is determined by the resistor (R) and capacitor (C) values: [ f = \frac{1}{4.4 \times R \times C} ]
• The output square wave is available at Pin 6 (Q) and its complement at Pin 7 (!Q).

• Connect a resistor between Pin 10 and Vcc, and a capacitor between Pin 9 and GND.
• Set Pin 3 (A/!M) to logic LOW to enable monostable mode.
• Apply a trigger pulse to Pin 5 to start the timing cycle.
• The pulse width is determined by the resistor (R) and capacitor (C) values: [ T = 2.48 \times R \times C ]
• The output pulse is available at Pin 6 (Q).

• Ensure the supply voltage (Vcc) is within the specified range (3V to 15V).
• Use decoupling capacitors (e.g., 0.1 µF) near the power supply pins to reduce noise.
• Avoid leaving unused input pins floating; connect them to GND or Vcc as needed.
• For precise timing, use high-quality resistors and capacitors with low tolerance.

The 4047 IC can be used with an Arduino UNO to generate a square wave. Below is an example of how to configure the IC in astable mode and read the output using Arduino:

1. Connect Pin 12 (Vcc) to the 5V pin of the Arduino.
2. Connect Pin 8 (GND) to the GND pin of the Arduino.
3. Connect a 10 kΩ resistor between Pin 1 and Pin 2.
4. Connect a 0.1 µF capacitor between Pin 2 and GND.
5. Set Pin 3 (A/!M) to HIGH (connect to 5V).
6. Connect Pin 6 (Q) to a digital input pin on the Arduino (e.g., Pin 2).

// Define the input pin for the 4047 IC output
const int inputPin = 2;

void setup() {
  pinMode(inputPin, INPUT); // Set the input pin as an input
  Serial.begin(9600);       // Initialize serial communication
}

void loop() {
  int state = digitalRead(inputPin); // Read the state of the 4047 output
  Serial.print("4047 Output State: ");
  Serial.println(state); // Print the state to the Serial Monitor
  delay(500);            // Wait for 500 ms before reading again
}

1. No Output Signal in Astable Mode

   • Cause: Incorrect resistor or capacitor values.
   • Solution: Verify the R and C values and ensure they are within the recommended range.

2. No Response in Monostable Mode

   • Cause: Trigger pulse not applied or incorrect timing components.
   • Solution: Ensure a proper trigger pulse is applied to Pin 5 and check the R and C values.

3. Output Signal is Unstable

   • Cause: Noise or insufficient decoupling.
   • Solution: Add a 0.1 µF decoupling capacitor near the Vcc and GND pins.

4. High Power Consumption

   • Cause: Supply voltage too high or incorrect connections.
   • Solution: Ensure the supply voltage is within the specified range (3V to 15V).

Q1: Can the 4047 IC generate a sine wave?
A1: No, the 4047 IC generates square waves. For sine wave generation, additional circuitry is required.

Q2: What is the maximum frequency the 4047 IC can generate?
A2: The 4047 IC can generate frequencies up to 1 MHz in astable mode, depending on the R and C values.

Q3: Can I use the 4047 IC with a 3.3V power supply?
A3: Yes, the IC operates with supply voltages as low as 3V, making it compatible with 3.3V systems.

Q4: What happens if I leave the A/!M pin floating?
A4: Leaving the A/!M pin floating can cause unpredictable behavior. Always connect it to either Vcc (astable mode) or GND (monostable mode).