SBASAH3A April   2022  – September 2022 PCMD3140-Q1

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  Timing Requirements: I2C Interface
    7. 6.7  Switching Characteristics: I2C Interface
    8. 6.8  Timing Requirements: TDM, I2S or LJ Interface
    9. 6.9  Switching Characteristics: TDM, I2S or LJ Interface
    10.     Timing Requirements: PDM Digital Microphone Interface
    11. 6.10 Switching Characteristics: PDM Digial Microphone Interface
    12. 6.11 Timing Diagrams
    13. 6.12 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Serial Interfaces
        1. 7.3.1.1 Control Serial Interfaces
        2. 7.3.1.2 Audio Serial Interfaces
          1. 7.3.1.2.1 Time Division Multiplexed Audio (TDM) Interface
          2. 7.3.1.2.2 Inter IC Sound (I2S) Interface
          3. 7.3.1.2.3 Left-Justified (LJ) Interface
        3. 7.3.1.3 Using Multiple Devices With Shared Buses
      2. 7.3.2 Phase-Locked Loop (PLL) and Clock Generation
      3. 7.3.3 Reference Voltage
      4. 7.3.4 Microphone Bias
      5. 7.3.5 Digital PDM Microphone Record Channel
      6. 7.3.6 Signal-Chain Processing
        1. 7.3.6.1 Programmable Digital Volume Control
        2. 7.3.6.2 Programmable Channel Gain Calibration
        3. 7.3.6.3 Programmable Channel Phase Calibration
        4. 7.3.6.4 Programmable Digital High-Pass Filter
        5. 7.3.6.5 Programmable Digital Biquad Filters
        6. 7.3.6.6 Programmable Channel Summer and Digital Mixer
        7. 7.3.6.7 Configurable Digital Decimation Filters
          1. 7.3.6.7.1 Linear Phase Filters
            1. 7.3.6.7.1.1 Sampling Rate: 7.35 kHz to 8 kHz
            2. 7.3.6.7.1.2 Sampling Rate: 14.7 kHz to 16 kHz
            3. 7.3.6.7.1.3 Sampling Rate: 22.05 kHz to 24 kHz
            4. 7.3.6.7.1.4 Sampling Rate: 29.4 kHz to 32 kHz
            5. 7.3.6.7.1.5 Sampling Rate: 44.1 kHz to 48 kHz
            6. 7.3.6.7.1.6 Sampling Rate: 88.2 kHz to 96 kHz
            7. 7.3.6.7.1.7 Sampling Rate: 176.4 kHz to 192 kHz
            8. 7.3.6.7.1.8 Sampling Rate: 352.8 kHz to 384 kHz
            9. 7.3.6.7.1.9 Sampling Rate: 705.6 kHz to 768 kHz
          2. 7.3.6.7.2 Low-Latency Filters
            1. 7.3.6.7.2.1 Sampling Rate: 14.7 kHz to 16 kHz
            2. 7.3.6.7.2.2 Sampling Rate: 22.05 kHz to 24 kHz
            3. 7.3.6.7.2.3 Sampling Rate: 29.4 kHz to 32 kHz
            4. 7.3.6.7.2.4 Sampling Rate: 44.1 kHz to 48 kHz
            5. 7.3.6.7.2.5 Sampling Rate: 88.2 kHz to 96 kHz
            6. 7.3.6.7.2.6 Sampling Rate: 176.4 kHz to 192 kHz
          3. 7.3.6.7.3 Ultra-Low-Latency Filters
            1. 7.3.6.7.3.1 Sampling Rate: 14.7 kHz to 16 kHz
            2. 7.3.6.7.3.2 Sampling Rate: 22.05 kHz to 24 kHz
            3. 7.3.6.7.3.3 Sampling Rate: 29.4 kHz to 32 kHz
            4. 7.3.6.7.3.4 Sampling Rate: 44.1 kHz to 48 kHz
            5. 7.3.6.7.3.5 Sampling Rate: 88.2 kHz to 96 kHz
            6. 7.3.6.7.3.6 Sampling Rate: 176.4 kHz to 192 kHz
            7. 7.3.6.7.3.7 Sampling Rate: 352.8 kHz to 384 kHz
      7. 7.3.7 Voice Activity Detection (VAD)
      8. 7.3.8 Interrupts, Status, and Digital I/O Pin Multiplexing
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode or Software Shutdown
      2. 7.4.2 Active Mode
      3. 7.4.3 Software Reset
    5. 7.5 Programming
      1. 7.5.1 Control Serial Interfaces
        1. 7.5.1.1 I2C Control Interface
          1. 7.5.1.1.1 General I2C Operation
          2. 7.5.1.1.2 I2C Single-Byte and Multiple-Byte Transfers
            1. 7.5.1.1.2.1 I2C Single-Byte Write
            2. 7.5.1.1.2.2 I2C Multiple-Byte Write
            3. 7.5.1.1.2.3 I2C Single-Byte Read
            4. 7.5.1.1.2.4 I2C Multiple-Byte Read
    6. 7.6 Register Maps
      1. 7.6.1 Page 0 Registers
      2. 7.6.2 Page 1 Registers
      3. 7.6.3 Programmable Coefficient Registers
        1. 7.6.3.1 Programmable Coefficient Registers: Page 2
        2. 7.6.3.2 Programmable Coefficient Registers: Page 3
        3. 7.6.3.3 Programmable Coefficient Registers: Page 4
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Four-Channel Digital PDM Microphone Recording
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Example Device Register Configuration Script for EVM Setup
        3. 8.2.1.3 Application Curves
    3. 8.3 What to Do and What Not to Do
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.6.4 Programmable Digital High-Pass Filter

To remove the DC offset component and attenuate the undesired low-frequency noise content in the record data, the device supports a programmable high-pass filter (HPF). The HPF is not a channel-independent filter setting but is globally applicable for all the channels. This HPF is constructed using the first-order infinite impulse response (IIR) filter, and is efficient enough to filter out possible DC components of the signal. Table 7-13 shows the predefined –3-dB cutoff frequencies available that can be set by using the HPF_SEL[1:0] register bits of P0_R107. Additionally, to achieve a custom –3-dB cutoff frequency for a specific application, the device also allows the first-order IIR filter coefficients to be programmed when the HPF_SEL[1:0] register bits are set to 2'b00. Figure 7-17 illustrates a frequency response plot for the HPF filter.

Table 7-13 HPF Programmable Settings
P0_R107_D[1:0] : HPF_SEL[1:0]-3-dB CUTOFF FREQUENCY SETTING-3-dB CUTOFF FREQUENCY AT 16-kHz SAMPLE RATE-3-dB CUTOFF FREQUENCY AT
48-kHz SAMPLE RATE
00Programmable 1st-order IIR filterProgrammable 1st-order IIR filterProgrammable 1st-order IIR filter
01 (default)0.00025 × fS4 Hz12 Hz
100.002 × fS32 Hz96 Hz
110.008 × fS128 Hz384 Hz

 

GUID-3DA4891F-9467-4644-921B-98474D40A913-low.gifFigure 7-17 HPF Filter Frequency Response Plot

Equation 1 gives the transfer function for the first-order programable IIR filter:

Equation 1. GUID-467C00D0-DF25-47F8-AFD0-8FA0B6BCEFC3-low.gif

The frequency response for this first-order programmable IIR filter with default coefficients is flat at a gain of 0 dB (all-pass filter). The host device can override the frequency response by programming the IIR coefficients in Table 7-14 to achieve the desired frequency response for high-pass filtering or any other desired filtering. If HPF_SEL[1:0] are set to 2'b00, the host device must write these coefficients values for the desired frequency response before powering-up any PDM channel for recording. These programmable coefficients are 32-bit, two’s complement numbers. Table 7-14 shows the filter coefficients for the first-order IIR filter.

Table 7-14 1st-Order IIR Filter Coefficients
FILTERFILTER COEFFICIENTDEFAULT COEFFICIENT VALUECOEFFICIENT REGISTER MAPPING
Programmable 1st-order IIR filter (can be allocated to HPF or any other desired filter)N00x7FFFFFFFP4_R72-R75
N10x00000000P4_R76-R79
D10x00000000P4_R80-R83