SBASAU2 May   2024 PCM1841-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Pin Configuration and Functions
  6. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements: TDM, I2S or LJ Interface
    7. 5.7 Switching Characteristics: TDM, I2S or LJ Interface
    8. 5.8 Timing Diagram
    9. 5.9 Typical Characteristics
  7. 6Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Hardware Control
      2. 6.3.2 Audio Serial Interfaces
        1. 6.3.2.1 Time Division Multiplexed Audio (TDM) Interface
        2. 6.3.2.2 Inter IC Sound (I2S) Interface
        3. 6.3.2.3 Left-Justified (LJ) Interface
      3. 6.3.3 Phase-Locked Loop (PLL) and Clock Generation
      4. 6.3.4 Input Channel Configurations
      5. 6.3.5 Reference Voltage
      6. 6.3.6 Microphone Bias
      7. 6.3.7 Signal-Chain Processing
        1. 6.3.7.1 Digital High-Pass Filter
        2. 6.3.7.2 Configurable Digital Decimation Filters
          1. 6.3.7.2.1 Linear Phase Filters
            1. 6.3.7.2.1.1 Sampling Rate: 8kHz or 7.35kHz
            2. 6.3.7.2.1.2 Sampling Rate: 16kHz or 14.7kHz
            3. 6.3.7.2.1.3 Sampling Rate: 24kHz or 22.05kHz
            4. 6.3.7.2.1.4 Sampling Rate: 32kHz or 29.4kHz
            5. 6.3.7.2.1.5 Sampling Rate: 48kHz or 44.1kHz
            6. 6.3.7.2.1.6 Sampling Rate: 96kHz or 88.2kHz
            7. 6.3.7.2.1.7 Sampling Rate: 192kHz or 176.4kHz
          2. 6.3.7.2.2 Low-Latency Filters
            1. 6.3.7.2.2.1 Sampling Rate: 16kHz or 14.7kHz
            2. 6.3.7.2.2.2 Sampling Rate: 24kHz or 22.05kHz
            3. 6.3.7.2.2.3 Sampling Rate: 32kHz or 29.4kHz
            4. 6.3.7.2.2.4 Sampling Rate: 48kHz or 44.1kHz
            5. 6.3.7.2.2.5 Sampling Rate: 96kHz or 88.2kHz
      8. 6.3.8 Dynamic Range Enhancer (DRE)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Hardware Shutdown
      2. 6.4.2 Active Mode
  8. 7Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9Revision History
  11.   Mechanical, Packaging, and Orderable Information

6.3.2.1 Time Division Multiplexed Audio (TDM) Interface

The rising edge of FSYNC starts the data transfer in TDM mode (also known as DSP mode) with the slot 0 data first. Immediately after the slot 0 data transmission, the remaining slot data are transmitted in order. FSYNC and each data bit is transmitted on the rising edge of BCLK (except the MSB of slot 0 when TX_OFFSET equals 0). Figure 6-1 to Figure 6-4 illustrate the protocol timing for TDM operation with various configurations.

PCM1841-Q1 TDM Mode Protocol Timing (FMT0 = LOW) In Target ModeFigure 6-1 TDM Mode Protocol Timing (FMT0 = LOW) In Target Mode
PCM1841-Q1 TDM Mode Protocol Timing (FMT0 = HIGH) In Target ModeFigure 6-2 TDM Mode Protocol Timing (FMT0 = HIGH) In Target Mode
PCM1841-Q1 TDM Mode Protocol Timing (FMT0 = LOW) In Controller ModeFigure 6-3 TDM Mode Protocol Timing (FMT0 = LOW) In Controller Mode
PCM1841-Q1 TDM Mode Protocol Timing (FMT0 = HIGH) In Controller ModeFigure 6-4 TDM Mode Protocol Timing (FMT0 = HIGH) In Controller Mode

For proper operation of the audio bus in TDM mode, the number of bit clocks per frame must be greater than, or equal to, the number of active output channels times the 32-bits word length of the output channel data. The device transmits a zero data value on SDOUT for the extra unused bit clock cycles. The device supports FSYNC as a pulse with a 1-cycle-wide bit clock, but also supports multiples as well.