Patent ID: 6060950
Filing Date: 2000-05-09
Classification: H03G

Abstract:
Gain control apparatus for selectively amplifying an input signal, said gain control apparatus comprising:a variable gain amplifier having selectable gain characteristics and coupled to receive electrical signals representative of the input signal, said variable gain amplifier for amplifying the electrical signals with a selected gain characteristic;a delta sigma modulator coupled to said variable gain amplifier in a gain control loop and exhibiting a signal transfer function and a noise transfer function, the signal transfer function and the noise transfer function exhibiting dissimilar characteristics said delta sigma modulator for generating a gain control signal of values which, when applied to said variable gain amplifier, are determinative of the selected gain characteristic by which the electrical signals are amplified, said delta sigma modulator for shaping a noise component of the gain control signal, such that the noise component is of frequencies offset in frequency by a frequency offset at least a selected amount relative to a fundamental frequency of the noise component.