SLES230A September   2008  – August 2015 PCM2912A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
      1. 7.6.1 ADC Digital Decimation Filter Frequency Response
      2. 7.6.2 ADC Digital High-Pass Filter Frequency Response
      3. 7.6.3 ADC Analog Antialiasing Filter Frequency Response
      4. 7.6.4 DAC Digital Interpolation Filter Frequency Response
      5. 7.6.5 DAC Analog FIR Filter Frequency Response
      6. 7.6.6 DAC Analog Low-Pass Filter Frequency Response
      7. 7.6.7 ADC
      8. 7.6.8 DAC
      9. 7.6.9 Supply Current
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Clock and Reset
      2. 9.3.2  DAC
      3. 9.3.3  ADC
      4. 9.3.4  Microphone Bias
      5. 9.3.5  Microphone Amplifier
      6. 9.3.6  Input PGA
      7. 9.3.7  Sidetone Programmable Attenuator
      8. 9.3.8  Output Programmable Attenuator
      9. 9.3.9  VCOM1 and VCCM2
      10. 9.3.10 Filter Pins
      11. 9.3.11 Interface Sequence
        1. 9.3.11.1 Power-On, Attach, and Play Back Sequence
        2. 9.3.11.2 Play, Stop, and Detach Sequence
        3. 9.3.11.3 Record Sequence
        4. 9.3.11.4 Suspend and Resume Sequence
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 USB Interface
        1. 9.5.1.1 Device Configuration
        2. 9.5.1.2 Interface #0
        3. 9.5.1.3 Interface #1
        4. 9.5.1.4 Interface #2
        5. 9.5.1.5 Endpoints
        6. 9.5.1.6 Internal Regulator
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10 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.

10.1 Application Information

The VBUS alerts the device when it has been plugged to a USB connection port. The /SSPND flag notifies when the USB input is idle for at least 5 ms; this flag can be used to control or notify subsequent circuits. More functional details can be found in Interface Sequence.

10.2 Typical Application

A bus-powered (Hi-power), +20-dB microphone amplifier application example is shown in Figure 37.

PCM2912A headset_les230.gif

NOTE:

X1: 6-MHz crystal resonator
C1, C8, C11, C14, C17, C18: 1 μF ceramic
C2, C3: 10 pF to 33 pF (depending on load capacitance of crystal resonator)
C4, C5: 100 pF ceramic
C6, C10: 3.3 μF
C7: 0.1 μF
C9: 0.22 μF electrolytic (depending on required frequency response for microphone input)
C13, C16: 100 μF electrolytic (depending on required frequency response for headphone output)
R1, R2: 22 Ω to 33 Ω
R3: 1.5 kΩ
R4: 1 MΩ
R5: 1 kΩ (depending on microphone characteristic)
R7, R8, R10, R11: 3.3 kΩ
R12, R13: 820 Ω (depending on LED drive current)
L1: 1 μH (DC resistance < 0.6 Ω)
It is possible to change maximum power if total power of actual application does not require over 100 mA (set POWER = low to configure as low-power device).
Figure 37. USB Headset Application

NOTE

The circuit in Figure 37 is for information only. Total board design should be considered in order to meet the USB specification as a USB-compliant product.

10.2.1 Design Requirements

For this design example, use the parameters listed in Table 7.

Table 7. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Input voltage range 4.35 V to 5.25 V
Current 80 mA to 100 mA
Input clock frequency 11.994 MHz to 12.006 MHz

10.2.2 Detailed Design Procedure

The PCM2912A is a simple design device, as can connect directly to a USB port. The device only requires decoupling capacitors on the voltage source pins and the output filter for the headphone amplifier; a recommended output filter is the one implemented in the PCM2912AEVM, shown in the user's guide (SBAU141).

10.2.3 Application Curves

For the application curves, see the graphs listed in Table 8.

Table 8. Table of Graphs

FIGURE
ADC Digital Decimation Filter Frequency Response Overall Characteristic Figure 1
Stop Band Attenuation Figure 2
Passband Ripple Figure 3
Transient Band Response Figure 4
ADC Digital High-Pass Filter Frequency Response Stop Band Characteristic Figure 5
Passband Characteristic Figure 6
ADC Analog Antialiasing Filter Frequency Response Stop Band Characteristic Figure 7
Passband Characteristic Figure 8
DAC Digital Interpolation Filter Frequency Response Stop Band Attenuation Figure 9
Passband Ripple Figure 10
Transient Band Response Figure 11
DAC Analog FIR Filter Frequency Response Stop Band Characteristic Figure 12
Passband Characteristic Figure 13
DAC Analog Low-Pass Filter Frequency Response Stop Band Characteristic Figure 14
Passband Characteristic Figure 15
ADC THD+N at – 1 dB vs Temperature Figure 16
Dynamic Range and Signal-to-Noise Ratio vs Temperature Figure 17
THD+N at – 1 dB vs Supply Voltage Figure 18
Dynamic Range and Signal-to-Noise Ratio vs Supply Voltage Figure 19
THD+N at – 1 dB vs Sampling Frequency Figure 20
Dynamic Range and Signal-to-Noise Ratio vs Sampling Frequency Figure 21
DAC THD+N at 0 dB vs Temperature Figure 22
Dynamic Range and Signal-to-Noise Ratio vs Temperature Figure 23
THD+N at 0 dB vs Supply Voltage Figure 24
Dynamic Range and Signal-to-Noise Ratio vs Supply Voltage Figure 25
THD+N at 0 dB vs Sampling Frequency Figure 26
Dynamic Range and Signal-to-Noise Ratio vs Sampling Frequency Figure 27
Supply Current Supply Current vs Supply Voltage Figure 28
Supply Current vs Sampling Frequency Figure 29
Supply Current vs Temperature at Suspend Mode Figure 30