SBAA497B May   2021  – April 2022 PCM3120-Q1 , PCM5120-Q1 , PCM6120-Q1 , TLV320ADC3120 , TLV320ADC5120 , TLV320ADC6120

 

  1.   Trademarks
  2. 1Introduction
  3. 2Infinite Impulse Response Filters
    1. 2.1 Digital Biquad Filter
  4. 3TLV320ADCx120 and PCMx120-Q1 Digital Biquad Filters
    1. 3.1 Filter Design Using PurePath Console
      1. 3.1.1 Example Generating Programmable Biquad Coefficients Using PurePath Console
    2. 3.2 How to Generate N0, N1, N2, D1, and D2 Coefficients with a Digital Filter Design Package
    3. 3.3 Avoid Overflow Conditions
    4. 3.4 Digital Biquad Filter Allocation to Output Channel
    5. 3.5 Programmable Coefficient Registers for Digital Biquad Filters 1–6
    6. 3.6 Programmable Coefficient Registers for Digital Biquad Filters 7–12
  5. 4How to Program the Digital Biquad Filters on the TLV320ADCx120 and PCMx120-Q1
  6. 5Typical Audio Applications for Biquad Filtering
    1. 5.1 Parametric Equalizers
  7. 6Crossover Networks
  8. 7Voice Boost
  9. 8Bass Boost
  10. 9Removing 50 Hz–60 Hz Hum With Notch Filters
  11.   A Digital Filter Design Techniques
    1.     A.A Analog Filters
  12.   B Related Documentation
  13.   B Revision History

4 How to Program the Digital Biquad Filters on the TLV320ADCx120 and PCMx120-Q1

Coefficients of Digital Biquad Filters can be implemented by running a command script to send an I2C command to the EVM. The following script segment shows how to program the coefficients for a set of filters for 5-dB boost at 500 Hz with a bandwidth of 400 Hz, cut –5 dB at 2 kHz with 3-kHz bandwidth, and a Notch filter at 60 Hz with 50-Hz bandwidth for channel 1.


# Select Page 2
w 9C 00 02
# Write Coefficient N0, N1, N2, D1, D2 for Biquad Filter 1
w 9C 08 7f ff ff ff 85 dc e2 7d 74 cc 68 8f 7c 77 a7 18 86 87 f4 ee 
# Write Coefficient N0, N1, N2, D1, D2 for Biquad Filter 5
w 9C 58 71 80 7d b6 a4 5b f4 41 4c 3e c3 29 5b a4 0b bf c2 40 bf 20
# Select Page 3
w 9C 00 03
# Write Coefficient N0, N1, N2, D1, D2 for Biquad Filter 9
w 9C 30 7f 95 1d c9 80 6b e4 18 7f 95 1d c9 7f 94 1b e8 80 d5 c4 6d