Patent ID: 8228132
Filing Date: 2012-07-24
Classification: H03B

Abstract:
1. A voltage-controlled oscillator (VCO) robust against power noise, comprising: a regulating unit configured to serve a stable virtual supply voltage based on a reference voltage to a VCO core circuit; a power noise removal unit configured to remove power noise of the virtual supply voltage provided by the regulating unit; and the VCO core circuit, wherein the regulating unit comprises a first NMOS transistor and a first amplifier, wherein the first NMOS transistor has a source terminal connected with the VCO core circuit, a drain terminal connected with a supply voltage, and a gate terminal connected with an output terminal of the first amplifier so that a cascoded state is established; and wherein the first amplifier has differential input terminals connected with a source terminal of the first NMOS transistor and a reference voltage respectively, and an output terminal connected to a gate terminal of the first NMOS transistor, where the reference voltage is a positive input of the first amplifier and the source terminal of the first NMOS transistor is a negative input of the first amplifier so that the first NMOS transistor and the first amplifier form a closed-circuit loop.