Integrated cable modem

摘要

The present invention is an integrated cable modem tuner. In one embodiment, the upstream path and the downstream path are integrated on a common semiconductor substrate. The down-stream path can include a TV tuner and digital receiver portion that is integrated on a common semiconductor substrate with the power amplifier of the upstream path. In another embodiment, the TV tuner is implemented on a first semiconductor substrate and the digital receiver portion and the power amplifier are configured on a second semiconductor substrate. However, the two substrates are mounted on a common carrier so that the cable modem appears to be a single chip configuration to the user.

主权项

1. An integrated cable modem, comprising:
a down-conversion circuit configured to down-convert a downstream signal in accordance with a quadrature local oscillator signal to generate a plurality of down-converted components; a multiplexer configured to interleave the plurality of down-converted components; an analog-to-digital converter (ADC), coupled to an output of the multiplexer, configured to convert the interleaved plurality of down-converted components into a single data stream; a demodulator circuit configured to generate a plurality of digital outputs based on the single data stream; and an oscillator circuit coupled to an output of the demodulator circuit and to an input of the down-conversion circuit, and wherein the oscillator circuit is configured to:
receive an error signal that is generated based on the plurality of digital outputs,adjust a quadrature component of the quadrature local oscillator signal based on the error signal, andsend the adjusted quadrature local oscillator signal to the down-conversion circuit.