Hardware/Parallelport/Audio ADC DAC

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Audio ADC DAC board

The board bases on 2 different chips.

  • ADC Chip is a BB PCM1804 full differential analog input 24-BIT, 192-kHz stereo A/D converter.
  • DAC Chip is a BB PCM1793 24-BIT, 192kHz Stereo D/A converter.
Version Photo Schematics Description
V1.0 HEB ADC-DAC Mezza ADC DAC Schematic PDF ADC & DAC parallelport board

Both the ADC and DAC Chips are supplied by +5V. These power is generated in two steps from the +3.3V power supply from the FPGA-EBS. In the first step with a steup up from +3.3V to ~+5.5V and in a second step, for the DAC and the ADC separably, a VLDO to +5V.


ADC-DAC board with soldered resistors for DAC DC-offset

The DAC is designed for audio applications, and therefore cancels out any DC-offset. If you need a DC-offset for your application, you have to solder a pull-up resistor on the negative input of the OpAmp, which then forms a voltage divider with the 3k3 Ω resistor (i.e. optimally a 6k6 Ω resistor).

See the schematic for further information regarding offset and gain for the ADC and gain and LPF for the DAC.


Filiere Promotions for the EMVS Day
(Potential) future students can build a Class-D Audio Amplifier.
The DAC links the triangle signal generated by an FPGA to the mirror driver board.
The ADC converts the signal received from the optical sensor for processing by an FPGA.

Audio Amp Test

  • Use FPGA-EBS v2.x
  • Connect the AD-DA board via parallel cable
  • Connect the Rotary Switch board via parallel cable
  • Connect Mezzanine Audio Adapter board
  • Power the FPGA via the Mezzanine connector
  • Connect Step-Up with a coax cable
  • Connect H-Bridge with the 1 Pin parallel cable
  • Connect Step-Up with the H-bridge
  • Connect H-Bridge with the Lowpass filter for the Loudspeaker
  • Connect the Loudspeaker
  • Power Step-up and H-Bridge with +12V - Gnd

Test of the PP HEB ADC DAC Board

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