Patent ID: 7061987
Filing Date: 2006-06-13
Classification: H04L,H04M,H04Q

Abstract:
1. A wideband analog front-end (AFE) circuit for digital subscriber line (DSL) systems, comprising: a current-steering digital to analog converter (DAC) configured to receive a set of digital data bits at an AFE input and to provide a first current output that is a representation of the set of digital data bits at a DAC output; a current-to-voltage converter coupled to the DAC output, the converter configured to receive the first current output and to provide a first voltage output that is a representation of the first current output at a converter output; a transmit amplifier TXAMP coupled to the converter output, the TXAMP configured to provide a voltage gain to the first voltage output at an amplifier output; a smoothing filter TXF SMF coupled to the amplifier output, the TXF SMF configured to remove unwanted frequency components from the first voltage output and to provide a first filtered output signal at a filter output; an asymmetric digital subscriber line (ADSL) transmit filter ADSL TXF coupled to the filter output, the ADSL TXF configured to remove frequency components existing outside an ADSL transmit frequency spectrum in the first filtered output signal and to provide an ADSL transmit signal at a second filter output; a transmit buffer TXBUFFER coupled to the second filter output, the TXBUFFER configured to receive the ADSL transmit signal and to provide a buffered signal output at an AFE output; a hybrid amplifier HYBRID AMP configured to receive an analog DSL signal from a second AFE input, and to provide an amplified DSL signal at a hybrid amplifier output; a receive filter RXF coupled to the hybrid amplifier output, the RXF configured to remove unwanted frequency components from the amplified DSL signal and to provide a filtered receive signal at a receive filter output; a programmable-gain-amplifier PGA an ADSL receive filter AAF ADSL RXF coupled to the PGA output, the AAF ADSL RXF configured to receive the amplified receive signal, remove unwanted frequency components from the amplified receive signal and to provide a second filtered receive signal at an AAF output; a Rausch filter amplifier AAF ADSL PGA coupled to the AAF output, the AAF ADSL PGA configured to receive the second filtered receive signal, remove unwanted frequency components from the second filtered receive signal and to provide a third filtered receive signal at a Rausch output; an analog-to-digital converter (ADC) buffer coupled to the Rausch output, the buffer configured to receive the third filtered receive signal and to provide a buffered receive signal at a receive buffer output; and an analog-to-digital converter (ADC) coupled to the receive buffer output, the ADC configured to receive the buffered receive signal and to provide a digital representation of the buffered receive signal at a second AFE output.