Mikael M Gustavsson

6614374, Sep 2, 2003

May 14, 2001

09/855080

Mikael Gustavsson - Eatontown NJ
Nianxiong Tan - Newport Beach CA

Globespanvirata, Inc. - Red Bank NJ

H03M 300

341143, 341118, 341120, 341144

A SINC filter for an oversampling Sigma-Delta digital to analog converter (OSDAC) having a cascaded construction that results in reduced sensitivity to capacitor mismatch. Specifically, the SINC filter circuit filter may be defined by a transfer function H(z), which is further defined by first constituent transfer functions H (z) and H (z). The constituent transfer functions may be implemented in a cascaded fashion. Preferably, one of the cascaded sections includes a resistor string that defines a plurality of reference voltages. A plurality of switching elements are configured to controllably switch these reference voltages to a capacitor of a tap.

62688154, Jul 31, 2001

Mar 3, 2000

9/517979

Mikael Gustavsson - Eatontown NJ
Nianxiong Tan - Howell NJ

Globespan, Inc. - Red Bank NJ

H03M 300

341143

An improved SC filter for OSDACs for asynchronous digital subscriber line (ADSL) applications. More specifically, an improved switched-capacitance (SC) filter for an over-sampled digital to analog converter intended for use in a multi-mode analog front end for a host of ADSL applications. The SC filter is configured for low power consumption and for a low-ambient noise floor across the frequencies of interest. The SC filter is further configured to drive a resistive load of a few kohms and for low signal distortion. The SC filter lowers power consumption by decimating the input waveform and reducing the number of operational amplifiers in the circuit.