Back to results
US 6,265,941 B1Granted
Balanced differential amplifier having common mode feedback with kick-start
AssigneeAgere Systems Guardian Corp.
InventorDouglas D. Lopata
Life of this patent
Estimating the term…
Abstract
A differential amplifier including a balanced differential amplifier circuit having common-mode feedback with input stage tail current servoing now includes a kickstart circuit that ensures that the circuit will always start up and operate in its intended operating region, thus eliminating any latch-up or dead zone problems.
Claims23
A differential amplifier circuit, comprising:
- a balanced differential amplifier circuit including first and second input ports and first and second output ports;
- a common-mode feedback circuit connected to the first and second output ports of the differential amplifier circuit and generating a common-mode feedback signal, the common-mode feedback signal being coupled back to a predetermined circuit node of the balanced differential amplifier circuit and forming a common-mode servo loop thereby;
- a kick-start circuit connected to the common-mode feedback circuit and generating a kick-start feedback signal, the kick-start feedback signal being coupled to a predetermined circuit node of the differential amplifier circuit to ensure that the circuit will start up and operate in an intended region of operation;
- and
- a differential feedback circuit connecting the first output port to the second input port and the second output port to the first input port.
2 more elements
A differential amplifier circuit, comprising:
- a balanced differential amplifier circuit including first and second input ports and first and second output ports;
- a common-mode feedback circuit including an electrical impedance network connected across the first and second output ports of the differential amplifier circuit and generating a common-mode feedback signal at a circuit node thereof, the common-mode feedback signal being coupled back to said circuit node of the balanced differential amplifier circuit and forming a common-mode servo loop thereby;
- and
- a kick-start circuit connected to the common-mode feedback circuit and generating a kick-start feedback signal, the kick-start feedback signal being coupled to a predetermined circuit node of the differential amplifier circuit to ensure that the circuit will start up and operate in an intended region of operation,
- said kick-start circuit including first and second kick-start feedback circuit elements coupled to said electrical impedance network and being responsive to said common-mode signal for generating and coupling first and second kick-start feedback signals to first and second circuit nodes of said intermediate output stage.
2 more elements
Dependencies are inferred from the claim text.