SBAU363A February   2021  – March 2022 PCM1820 , PCM1820-Q1 , PCM1821 , PCM1821-Q1 , PCM1822 , PCM1822-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Power Supply
  4. 3Hardware Configuration
  5. 4PCM182xEVM /PCM182xQ1EVM Inputs
    1. 4.1 Onboard Microphone Inputs
    2. 4.2 Line Inputs
  6. 5Layer Plots
  7. 6Schematics
  8. 7Bill of Materials
  9. 8Revision History

4 PCM182xEVM /PCM182xQ1EVM Inputs

The PCM1820/PCM1820-Q1 device is intended to be driven with differential line or microphone inputs. Each of the inputs has a 1-µF AC coupling film capacitor. Coupled with the 2.5-kΩ input impedance of PCM1820/PCM1820-Q1 , this sets the high pass filter cutoff frequency at approximately 63-Hz. PCM1821/PCM1821-Q1 has an input impedance of 10-kΩ, setting the cutoff frequency at 16-Hz. This can be adjusted by replacing the input AC coupling capacitors on the EVM if necessary. Figure 4-1 shows the architecture of the inputs to the evaluation module. The EVM supports a differential full scale input range of 2 VRMS with an AVDD of 3.3 V.

Please Note: PCM1822EVM/PCM1822Q1EVM is set up to support single ended inputs.

Figure 4-1 PCM182x /PCM182x-Q1 Input Architecture