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PCM5102A

README.md

PCM 5102A interface for Raspberry PI

PCM5102A DAC board

This board essentially consists of a PCM5102A DAC and TPA6132A2 amplifier ICs.

PCM5102A IC is used in PLL operation schematic. It means SCK pin is not used and frequency generation happens internally, using phase-locked loop control system. According to the datasheed, this configuration is not in any way bad and even slightly reduces electromagnetic interference. I am using PCM5102A because it has high sound quality and mute circuitry. Also, I ordered a board with this chip to test with Raspberry Pi before starting my own one.

I added TPA6132A2 headphone amplifier to isolate DAC from other devices. It is used in a single-ended input signal mode. I have concerns about damaging the DAC with short circuit, so that's why there's a tiny amplifier IC.

Current 2-ldo schematic is inspired by "GY" board from AliExpress. I got a working one at WavGat store.

There are also 3-ldo versions of the same schematic by AiDiy.cc. I guess it has a separate digital, analog and charge pump LDO, and it's a well-known AMS-1117-3.3, at that! It will be nice to test if there is any difference in sound later.

This board is designed in KiCad 5.1.6. It has 5V input voltage and 3.3V I²S voltage. Issues and advices are welcome!

Progress

  • I checked schematic using two datasheets paying as much attention as I can. It is still possible to encounter some issues and I haven't tested the board design yet.
  • I found out my 5V label is not related to the signal. RaspberryPi signal level is 3.3V. Changes are not required, since board is based on a design, tested with RaspberryPi.

To-Do

  • Do a toner-transfer method test
  • Test with jumpers
  • Remove excess power wiring from the layout
  • Do a second toner-transfer method test board
  • Add labels on the board to mark inputs and outputs
  • Order a test batch at PCBWay / JLCPCB / etc.
  • Add labels after the best board layout is established
  • It will be nice to have optocouples to control the DAC and AMP mute circuitry after the prototype is working. (Analyze ChipDip mute circuit below)
  • It will be interesting to test 1 and 3 LDO configuration later. It seems the datasheet relies on one LDO, while AiDiy schematic relies on three.
  • Add a MUTE pin controlling optocouples for DAC and AMP ICs

UPD: TPA6132 breakout board is here, so I can test it before I do toner-transfer. Sep 10, 2020.

Datasheets

Other links