SLES023D December   2001  – December 2016 PCM1802

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
      1. 6.6.1 Typical Characteristics: Internal Filter
        1. 6.6.1.1 Digital Filter: Decimation Filter Frequency Response
        2. 6.6.1.2 HPF (High-Pass Filter) Frequency Response
        3. 6.6.1.3 Analog Filter: Antialiasing Filter Frequence Response
      2. 6.6.2 Typical Characteristics: Output Spectrum
      3. 6.6.3 Typical Characteristics: Supply Current
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Hardware Control
      2. 7.3.2 Power-On Reset Sequence
      3. 7.3.3 System Clock
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Down, HPF Bypass, Oversampling Control
      2. 7.4.2 Serial Audio Data Interface
        1. 7.4.2.1 Data Format
        2. 7.4.2.2 Interface Timing
        3. 7.4.2.3 Synchronization With Digital Audio System
      3. 7.4.3 Master Mode
      4. 7.4.4 Slave Mode
      5. 7.4.5 Interface Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Control Pins
        2. 8.2.2.2 DSP or Audio Processor
        3. 8.2.2.3 Input Filters
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 VCC and VDD Pins
      2. 10.1.2 AGND and DGND Pins
      3. 10.1.3 VIN Pins
      4. 10.1.4 VREF1 Pin
      5. 10.1.5 VREF2 Pin
      6. 10.1.6 DOUT Pin
      7. 10.1.7 System Clock
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

8.1 Application Information

The PCM1802 device is suitable for wide variety of cost-sensitive consumer applications requiring good performance and operation with a 5-V analog supply and 3.3-V digital supply.

8.2 Typical Application

Figure 28 illustrates a typical circuit connection diagram in which the cutoff frequency of the input HPF is about 8 Hz.

PCM1802 s0026-02.gif
1. C1, C2: A 1-µF capacitor gives a 8-Hz (τ = 1 µF × 20 kΩ) cutoff frequency for input HPF in normal operation and requires a power-on settling time with a 20-ms time constant during the power-on initialization period.
2. C3, C4: Bypass capacitors, 0.1-µF ceramic and 10-µF tantalum, depending on layout and power supply
3. C5: TI recommends 0.1-µF ceramic and 10-µF tantalum capacitors.
4. C6: TI recommends 0.1-µF ceramic and 10-µF tantalum capacitors when using a noisy analog power supply. These capacitor are not required for a clean analog supply.
5. R1: TI recommends a 1-kΩ resistor when using a noisy analog power supply. This resistor is shorted for a clean analog supply.
Figure 28. Typical Circuit Connection

8.2.1 Design Requirements

For this design example, use the parameters listed in Table 10 as the input parameters.

Table 10. Design Parameters

PARAMETER VALUE
Analog input voltage 0 VP–P to 3 VP–P
Output PCM audio data
System clock input frequency 2.048 MHz to 49.152 MHz
Output sampling frequency 8 kHz to 96 kHz
Power supply 3.3 V and 5 V

8.2.2 Detailed Design Procedure

8.2.2.1 Control Pins

The FMT, MODE, OSR, and BYPASS control pins are controlled by tying up to VDD, down to GND, or driven with GPIO from the DSP or audio processor.

8.2.2.2 DSP or Audio Processor

In this application a DSP or audio processor acts as the audio master, and the PCM1802 acts as the audio slave. This means the DSP or audio processor must be able to output audio clocks that the PCM1802 can use to process audio signals.

8.2.2.3 Input Filters

For the analog input circuit an AC-coupling capacitor must be placed in series with the input. This removes the DC component of the input signal. An RC filter can also be implemented to filter out of band noise to reduce aliasing. Equation 1 calculates the cutoff frequency of the optional RC filter for the input.

Equation 1. PCM1802 eq_1_SLES023.gif

8.2.3 Application Curve

PCM1802 sles023_g015.gif Figure 29. Amplitude vs Frequency