Teardown HD-901T2 DVB-T2
That DTV stick is basically almost same than RTL2832U + R820T reference design, but there is one big difference - external DVB-T/T2/C demodulator. It is also a little bit bizarre as it advertises unofficial SDR (provided by RTL2832P).
Looks like device is build upon some new Realtek reference design, whilst it may different somehow. Windows drivers are near Realtek drivers, but those are still customized (?) for that device. Drivers that are coming with the device, are in a quite bad shape as even standard BDA interface didn't work. Own Windows application is only application which could be used currently.
Initial Linux support is about to go in Kernel 3.13, or in a bad luck 3.14 as Kernel merge window is very near to open. Kernel driver has only DVB-T support at the moment, due to missing external DVB-T/T2/C demodulator driver.
Rafael Micro R828D
|RTL2832P, MN88472, R828D|
There is own 20.500 MHz crystal, which offers clock source for demodulator. TS bus (between RTL2832P and MN88472) is hardly visible. It is not clear whether it is connected using serial or parallel bus, though serial mode could be good guess, as there is no 8+ wires clearly visible needed for parallel mode.
I2C control bus is connected to RTL2832P I2C adapter.
Rafael Micro R828D
|Rafael Micro R828D|
Tuner IF bus is connected to both MN88472 and RTL2832P. Control bus, I2C, is wired to RTL2832P I2C adapter only (RTL2832P I2C adapter is property of integrated RTL2832 demodulator).
Only chip visible is 24C08 8k serial eeprom. It contains USB configuration information, e.g. device USB ID and manufacturer strings. It is connected to RTL2832P via I2C.
Black 3-leg component is IR-receiver. It is connected also to RTL2832P, which offers RAW mode remote controller signals.
Crystal "Y2", 22.500 MHz, for MN88472.
Crystal "Y3", 28.800 MHz, for RTL2832P.