How to Use PH-4502c: Examples, Pinouts, and Specs

The PH-4502c is a high-performance, low-noise operational amplifier developed by Arduino. It is designed for precision signal processing applications, offering a wide bandwidth and low distortion. These features make it an excellent choice for audio systems, instrumentation circuits, and other applications requiring accurate signal amplification and processing.

• Audio signal amplification and processing
• Instrumentation and measurement systems
• Active filters and oscillators
• Precision voltage followers
• Analog computing circuits

The PH-4502c operational amplifier is engineered for high precision and reliability. Below are its key technical specifications:

The PH-4502c is typically available in an 8-pin Dual Inline Package (DIP-8) or Small Outline Integrated Circuit (SOIC-8). Below is the pinout and description:

The PH-4502c operational amplifier is versatile and can be used in a variety of circuit configurations. Below are general guidelines for using the component effectively:

1. Power Supply: Connect the V+ pin (Pin 7) to the positive supply voltage and the V- pin (Pin 4) to the negative supply voltage. Ensure the supply voltage is within the specified range (±3V to ±18V).
2. Input Connections:
   • Connect the signal to be amplified to the inverting (Pin 2) or non-inverting input (Pin 3), depending on the desired configuration.
   • Use appropriate resistors and capacitors to set the gain and bandwidth of the amplifier.
3. Output Connection: The amplified signal will be available at the output pin (Pin 6). Connect this pin to the next stage of your circuit.
4. Offset Adjustment (Optional): If precise offset voltage adjustment is required, connect a 10 kΩ potentiometer between the Offset Null pins (Pins 1 and 5) and the wiper to V+.

• Decoupling Capacitors: Place decoupling capacitors (e.g., 0.1 µF ceramic and 10 µF electrolytic) close to the power supply pins to reduce noise and improve stability.
• Input Impedance: Ensure the input impedance of the circuit is high enough to avoid loading the signal source.
• Thermal Management: Operate the amplifier within the specified temperature range (-40°C to +85°C) to prevent thermal damage.
• Avoid Oscillations: Use proper feedback network design to prevent unwanted oscillations in the circuit.

The PH-4502c can be used with an Arduino UNO for signal amplification. Below is an example of a simple non-inverting amplifier circuit:

• The PH-4502c amplifies an analog signal, which is then read by the Arduino UNO's analog input pin.

// Example code for reading an amplified signal using Arduino UNO
// The amplified signal is connected to analog pin A0

const int analogPin = A0; // Define the analog input pin
int signalValue = 0;      // Variable to store the analog signal value

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
}

void loop() {
  signalValue = analogRead(analogPin); // Read the amplified signal
  Serial.print("Signal Value: ");      // Print the signal value to the Serial Monitor
  Serial.println(signalValue);
  delay(500); // Wait for 500 ms before the next reading
}

1. No Output Signal:

   • Cause: Incorrect power supply connections.
   • Solution: Verify that the V+ and V- pins are connected to the correct supply voltages.

2. Distorted Output:

   • Cause: Exceeding the input voltage range or improper feedback network design.
   • Solution: Ensure the input signal is within the specified range and check the feedback resistor values.

3. Oscillations or Noise:

   • Cause: Insufficient decoupling or poor PCB layout.
   • Solution: Add decoupling capacitors near the power supply pins and use a proper ground plane.

4. High Offset Voltage:

   • Cause: Offset voltage not adjusted.
   • Solution: Use a potentiometer to adjust the offset voltage via the Offset Null pins.

Q1: Can the PH-4502c be used for single-supply operation?
A1: Yes, the PH-4502c can operate with a single supply voltage. Connect the V- pin to ground and ensure the input signal is biased within the amplifier's input range.

Q2: What is the maximum gain achievable with the PH-4502c?
A2: The maximum gain depends on the feedback network design. However, for stable operation, it is recommended to keep the gain below 1000.

Q3: Can I use the PH-4502c for audio applications?
A3: Yes, the PH-4502c is well-suited for audio applications due to its low noise and wide bandwidth.

Q4: How do I protect the amplifier from damage?
A4: Use clamping diodes at the input to protect against voltage spikes and ensure the supply voltage does not exceed the specified range.