TDA18267 is a Full Spectrum Transceiver (FST). This device includes all the key functions to realize the front end of a multiple stream receiver and transmitter for a cable gateway.
The receive function of TDA18267 allows the parallel reception of up to 24 independent cable channels, each of them being at any frequency in the RF band from 42 MHz to 1002 MHz. Each channel can be 6 MHz or 8 MHz wide QAM modulated, according to ITU J/83 annex A, B or C. TDA18267 input is connected to the cable through a cable spectrum pre-processor as TDA18204 that amplifies and corrects the tilt of the cable spectrum. The output of the TDA18267 is connected to the main SoC using two high-speed serial links.
The transmit function of TDA18267 allows generating the return channel of a DOCSIS 3.0 cable modem, based on the signal coming from the main SoC through a high-speed serial link. Output of this section only requires a power amplifier as BGA3031 to drive the cable through a diplexer with the required power level.
TDA18267 realizes the complete 24-channel receive path and 8-channel transmit path using only 2.5 W.
The proprietary highly digitalized architecture enables accurate spectral analysis (from 50 MHz to 1350 MHz RF band) which can be useful for providing remote diagnostic tools to cable operators.