Abstract: An analog front-end circuit and method that supports multiple digital subscriber line (DSL) standards, including asymmetric digital subscriber line (ADSL) and very-high speed digital subscriber line (VDSL) is disclosed. The circuit incorporates multiple circuit blocks that can be selectively included into the transmit and receive paths of a DSL signal. It also permits selectable gain settings for signal amplifiers, and frequency bandwidth for signal filters that may be included in the transmit and receive paths. The receive path includes an analog-to-digital converter (ADC) that operates close to and exceeds the Nyquist sampling rate.

Abstract: The present invention provides a programmable ADC with bit conversion optimization and method therefor. The programmable ADC includes an amplifier, a programmable clock generator, a comparator, a successive approximation logic, a digital-to-analog converter, and a voltage converter. The amplifier is arranged to sample and hold an input analog signal to be converted into N digital data bits. The programmable clock generator generates a clock signal for each of the N-bits to trigger setting of one of the N-bit digital data bits such that each of the N bits is set during a time optimized for each bit. The comparator is coupled to receive and compare the input analog signal with a successively approximated analog signal to generate a digital output signal. The successive approximation logic is configured to successively set each of the N-bits in response to the digital output signal and the clock signal to generate a successively approximated N-bit digital data.