IAN CANADA HDMIPI PRO III I2S LVDS HDMI Interface

The Ian Canada HdmiPi Pro III is a digital transport interface dedicated to the transmission of I2S and DSD signals over HDMI. Its output stage uses discrete 1-bit LVDS drivers, combined with a secondary reclocking circuit that is also discrete, in order to limit noise and jitter during transfer to an external DAC. Operating exclusively in synchronous clock mode, it must be paired with a FifoPiMa, FifoPiQ7, FifoPiQ3 board or another compatible reclocking circuit.

The board uses a four-layer printed circuit board with dedicated shielding planes, impedance control of the LVDS lines and wideband power filtering networks, while its LDO-regulator-free design allows the direct use of a 3.3V power supply via supercapacitor or battery. This architecture supports PCM streams up to 1536kHz and native DSD up to DSD1024, with switches allowing the HDMI format to be adapted to the various DACs that accept I²S over HDMI, including those that do not follow the PS Audio pinout. The dedicated MUTE/DSDEN connector can be connected directly to FifoPiQ7II boards and later versions.

Compared to the previous generation, the HdmiPi Pro III features optimized clock drivers, with an added phase jitter rated approximately 50% lower, as well as a signal path adapted to high sampling rates, notably in PCM 768kHz and DSD1024. An MCLK master clock input in U.FL format is also placed under the board to reduce the length of the signal path, while enhanced local filtering, very low ESR capacitors and high-bandwidth networks limit power supply noise on sensitive circuits. Finally, the HDMI receiver power supply can be enabled or disabled via the S3 jumper, and a dedicated mechanical support stabilizes the HDMI connector when integrating into a device or a DIY project.