Patent ID: 6114981
Filing Date: 2000-09-05
Classification: H03M

Abstract:
An over-sampling D/A converter, comprising:(a) a .SIGMA. .DELTA. modulator for receiving a multibit digital signal to which a DC offset value is added, and outputting a first one-bit digital signal;(b) a signal generator for receiving the first one-bit digital signal and a clock signal, generating a second digital signal, which is a logical multiplication of the first one-bit digital signal and the clock signal, and a third digital signal, which is a logical addition of the first one-bit digital signal and an inverted signal of the clock signal, and adding the second digital signal to the third digital signal to thus output a fourth digital signal; and(c) an analog filter for receiving the fourth digital signal and outputting an analog signal;wherein the analog filter includes a mute unit which short-circuits a feedback resistor element in a filter amplifier constituting the analog filter and sets a potential of the analog signal as a reference potential of the filter amplifier, andthe reference potential is set substantially equal to an average DC potential of the fourth digital signal.