Patent ID: 6324230
Filing Date: 2001-11-27
Classification: H03G,H04B

Abstract:
A multimode fast attack Automatic Gain Control (AGC) circuit having a forward transmission path with an amplifier stage responsive to receipt of a control signal that alters the amplifier stage gain component and a down mixer for providing a baseband signal at an output, the multimode fast attack AGC circuit comprising:an analog feedback loop at an output of the forward transmission path for generating an analog feedback control signal;a digital feedback loop at the output of the forward transmission path, including a digital to analog converter means for generating a digital feedback control signal;first switch means for alternatively coupling the analog feedback control signal or the digital feedback control signal to the amplifier stage;preset circuit means for setting the analog feedback control signal to known value; andsecond switch means for alternatively coupling the preset circuit means to the digital to analog converter means or a reference voltage.