part identification on an i2s to AES converter board

[jmibk]

Hi,

I got this i2s to AES audio converter board and like to use this on my own projects - so I have to identify all parts on it:


Can't get any hint on U2 (the smaller IC 20 pin)

On the left side, this is an WM8805 => https://statics.cirrus.com/pubs/proDatasheet/WM8805_v4.5.pdf
Middle top, this is an DS8921M => https://www.ti.com/lit/ds/symlink/ds8921.pdf
right side, this is an transformer PE-65612NL => https://www.mouser.at/datasheet/2/336/-370369.pdf
the unknown part is an P44AD, V244


It seems to be some kind of buffer.
On side pins 1-10:
Pin1 goes to the 2 row pin header and is labeled "OSD_ON"
Vias go to the 4 drill holes left of the chip marked "I2S".
The 4 lines to the 2 row pin header  are labeled also with I2S on the bottom side.
pin 10 is ground
pins 11 - 20:
4 lines through melf resistors are I2S lines (output on the P44AD, input on the WM8805)
pin 19 goes to the JMP2 and is connected to ground. JMP3 is open and connects Pin 19 to Pin1 if closed.
pin 20 is VCC 3V3

Maybe someone any hint about this part U2?

[2N3055]

74V244 (FAIRCHILD)

some sort of 74244 buffer.... probably something like 74VHC244

[jmibk]

probably something like 74VHC244

Thanks, that fits. Sometimes the parts are so simple and you can't spot the right thing. Thanks man!

For those that are interested in the circuit, here is the schematic (designators don't match with the board!) and some pics of the pcb's.

http://www.audiowerk.at/downloads/temp/eev/i2s_aes/Schematic_I2S_TO_AES_2021-01-08.pdf
http://www.audiowerk.at/downloads/temp/eev/i2s_aes/board1.jpg
http://www.audiowerk.at/downloads/temp/eev/i2s_aes/board2.jpg