Patent ID: 6765520
Filing Date: 2004-07-20
Classification: H03M

Abstract:
An analog-to-digital converter comprising:(a) a delta sigma modulator including i. an input conductor, and a first summing device having a first input coupled to the input conductor, ii. a quantizer for producing a modulator output signal on an output of the quantizer, iii. a plurality of integrators coupled sequentially between an output of the first summing device and an input of the quantizer, and iv. a digital-to-analog converter having an output coupled to a second input of the first summing device for providing feedback representative of signal conditions in one or more of the integrators; (b) a monitor circuit including an input responsive to one of a signal appearing at the quantizer input and a signal appearing at the quantizer output to produce a first control signal in response to occurrence of an instability condition caused by a out-of-range input signal on the input conductor and represented by the one of the signals at the quantizer input and quantizer output, respectively; (c) a logic circuit including a data input coupled to receive the modulator output signal, a data output for conducting a logic circuit output signal, and a first control input coupled to receive the first control signal; and (d) a digital filter including an input coupled to the data output of the logic circuit and an output coupled to an output bus of the analog-to-digital converter.