Low impedance automatic gain control circuit
Patent 5012202 Issued on April 30, 1991. Estimated Expiration Date: 
March 15, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 15, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesOptical receiver with improved dynamic range Nonintegrating receiver AGC circuit including a precision voltage clamp and method Patent #: 4718119 InventorApplicationNo. 494077 filed on 03/15/1990US Classes:330/284, Having attenuation means in signal transmission path250/214A, Amplifier type250/214AG, Automatic gain control330/308Including atomic particle or radiant energy impinging on a semiconductorExaminersPrimary: Mullins, James B.Attorney, Agent or FirmForeign Patent References
International ClassesH03F 003/08H03G 003/30 H01J 040/14 AbstractAn optical receiver circuit for an incoming optical signal having a variable power level includes an optical detector for receiving the optical signal and generating a current therefrom which varies with the optical signal power level. The current so generated is applied to a transimpedance amplifier. An automatic gain control (AGC) drive circuit is connected around the amplifier thereby increasing its dynamic range. The AGC drive circuit drives a FET which has one side thereof connected to the transimpedance amplifier for shunting current from the input thereof. A negative feedback circuit comprising an amplifier is connected across the FET, which comprises the resistive feedback element, thus reducing the FET resistance by a factor of 1+T, where T is the feedback circuit loop gain. | |
