Patent ID: 7205831
Filing Date: 2007-04-17
Classification: G05F

Abstract:
1. A noise canceling circuit, comprising: a first source terminal; a second source terminal; an output terminal; a reference voltage generator for generating a reference voltage, having an input connected to said first source terminal, and an input connected to said second source terminal, and an output; a bias current generator for generating a bias current determining an operating current, having a first source input, a second source input, and an output; a voltage-current generator for generating an output of a power circuit, having a first input connected to said first source terminal, a second input, and an output connected to said output terminal; a voltage divider for detecting a fluctuation of an output voltage at the output terminal, having an input connected to said second source terminal, an input connected to said output terminal, and an output; and an error amplifier for amplifying an error voltage between said reference voltage and an output voltage from said output of said voltage divider, having an input connected to said first source terminal, an input connected to said second source terminal, an input connected to said output of said reference voltage generator, an input connected to said output of said bias current generator, an input connected to said output of said voltage divider, and an output connected to said second input of said voltage-current generator, wherein said error amplifier comprises an input part, a load part, a noise suppression part, and a phase compensation capacitor, wherein said input part comprises a pair of first type semiconductor elements, wherein said load part comprises a pair of second type semiconductor elements, and wherein said noise suppression part (i) is disposed between said input part and said load part, (ii) has an input connected to said first source terminal, and (iii) comprises a pair of the first type semiconductor elements of different dimension in length or width.