Mediatek Corporation

Tsung-Kai Kao

Tien-Yu Lo

Chan-Hsiang Weng

Stacy Ho

Patrick Cooney

The invention provides an anti-aliasing filter (AAF) for discretization at a sampling period. The AAF may include an operational amplifier having an input terminal and an output terminal, a first capacitor coupled between the input terminal and the output terminal, a second capacitor, and a first switch coupled between the first capacitor and the second capacitor. During a first phase, the first switch may conduct the second capacitor to the first capacitor. During a second phase, the first switch may stop conducting the second capacitor to the first capacitor. The first phase may last for one said sampling period.

Anti-aliasing filter

Apparatus and methods for reducing noise and distortion in current digital-to-analog converters (IDACs). Compensating capacitors may be connected to current sources in an IDAC. The compensating capacitors may be driven with signalsderived from the output of the IDAC to cancel transient current spikes that would otherwise occur on the output of the IDAC.

Error cancellation in a current digital-to-analog converter of a continuous-time sigma-delta modulator

An analog-to-digital conversion that converts an input signal to an output signal by using multiple analog-to-digital converting circuits. A first analog-to-digital converting circuit generates a first signal based on the input signal and further outputs a feature signal of a first quantization error of the first analog-to-digital converting circuit. A second analog-to-digital converting circuit generates a second signal based on the input signal and the feature signal. The output combiner combines the first signal and the second signal to generate the output signal and thereby to reduce a quantization error factor in the output signal that is due to the first quantization error.

Growing community of inventors

Jhubei, Taiwan

Tsung-Kai Kao