How to Use PCM1803: Examples, Pinouts, and Specs

The PCM1803, manufactured by Texas Instruments, is a high-performance, 24-bit audio analog-to-digital converter (ADC) designed for high-fidelity audio applications. It offers a low noise floor, high dynamic range, and supports multiple audio sampling rates, making it ideal for professional audio equipment, consumer electronics, and other audio processing systems.

• Professional audio recording equipment
• Consumer audio devices (e.g., home theater systems, audio interfaces)
• Musical instruments with digital output
• Audio signal processing systems
• Voice recognition and audio analysis systems

• Resolution: 24-bit
• Dynamic Range: 103 dB (typical)
• Signal-to-Noise Ratio (SNR): 103 dB (typical)
• Total Harmonic Distortion + Noise (THD+N): -93 dB (typical)
• Sampling Rates: 16 kHz to 96 kHz
• Input Voltage Range: 0.6 Vpp to 2.1 Vpp (differential)
• Power Supply Voltage:
  • Analog: 5 V
  • Digital: 3.3 V
• Power Consumption: 85 mW (typical)
• Operating Temperature Range: -25°C to 85°C
• Package: 20-pin SSOP (Shrink Small Outline Package)

The PCM1803 comes in a 20-pin SSOP package. Below is the pin configuration and description:

1. Power Supply:

   • Connect the analog power supply (5 V) to the VCC pin and the digital power supply (3.3 V) to the VDD pin. Ensure proper decoupling capacitors are placed close to the power pins.
   • Connect AGND and DGND to the ground plane of the circuit.

2. Analog Input:

   • Provide differential analog audio signals to the VINL, VINL-, VINR, and VINR- pins. Use appropriate coupling capacitors to block DC components.

3. Clock Signals:

   • Provide a system clock (SCKI) to the PCM1803. The clock frequency should match the required sampling rate and oversampling ratio.

4. Audio Data Format:

   • Configure the audio data format using the FMT0 and FMT1 pins. The PCM1803 supports I2S, left-justified, and right-justified formats.

5. Audio Data Output:

   • Connect the DOUT pin to the digital audio receiver or microcontroller to capture the audio data.

6. Power-Down Mode:

   • Use the PDWN pin to enable or disable the power-down mode. Pull the pin low to enter power-down mode.

• Use a low-noise power supply and proper grounding techniques to minimize noise and interference.
• Ensure the system clock (SCKI) is stable and meets the required frequency specifications.
• Avoid leaving unused pins floating; tie them to the appropriate logic level as specified in the datasheet.
• Use high-quality differential amplifiers or preamps to drive the analog inputs for optimal performance.

The PCM1803 can be interfaced with an Arduino UNO to capture audio data via the I2S protocol. Below is an example Arduino sketch:

#include <I2S.h> // Include the I2S library for audio data handling

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);

  // Initialize I2S in receive mode
  if (!I2S.begin(I2S_PHILIPS_MODE, 44100)) {
    Serial.println("Failed to initialize I2S!");
    while (1); // Halt execution if I2S initialization fails
  }

  Serial.println("I2S initialized successfully.");
}

void loop() {
  // Check if audio data is available
  if (I2S.available()) {
    int sample = I2S.read(); // Read a 16-bit audio sample
    Serial.println(sample);  // Print the sample to the serial monitor
  }
}

• Ensure the Arduino UNO is connected to the PCM1803's DOUT, BCK, and LRCK pins.
• The I2S library is required for this example. Install it via the Arduino Library Manager if not already installed.

1. No Audio Output:

   • Verify that the system clock (SCKI) is correctly configured and stable.
   • Check the power supply connections and ensure proper decoupling.

2. Distorted Audio:

   • Ensure the analog input signals are within the specified voltage range.
   • Verify that the audio data format matches the receiver's configuration.

3. PCM1803 Not Responding:

   • Confirm that the PDWN pin is pulled high for normal operation.
   • Check all connections, especially the clock and data lines.

Q: Can the PCM1803 operate with a single-ended input?
A: No, the PCM1803 requires differential analog inputs for optimal performance. Use a differential amplifier to convert single-ended signals to differential.

Q: What is the maximum sampling rate supported by the PCM1803?
A: The PCM1803 supports sampling rates up to 96 kHz.

Q: How do I select the audio data format?
A: Use the FMT0 and FMT1 pins to configure the desired audio data format. Refer to the datasheet for the pin settings.

Q: Can I use the PCM1803 with a 3.3 V analog power supply?
A: No, the analog power supply (VCC) must be 5 V. The digital power supply (VDD) operates at 3.3 V.

By following this documentation, users can effectively integrate the PCM1803 into their audio systems and troubleshoot common issues.