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US 4,284,959 AGranted
Folded-cascode amplifier arrangement with cascode load means
AssigneeRCA Corporation
InventorsWilliam F. Heagerty, Richard L. Pryor
Life of this patent
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Abstract
A folded-cascode amplifier arrangement includes first and second transistors of complementary conductivity type and a constant current generator for supplying quiescent current thereto. Signal current flowing in the first transistor is coupled to the second transistor through current steering at the interconnection between their main conduction paths. The load means for the second transistor includes a cascode-connected third transistor for supplying load current thereto, which third transistor substantially increases the resistance of the load for correspondingly increasing the voltage gain of the amplifier arrangement. The amplifier voltage gain transfer function exhibits a frequency response dominated by a single pole.
Claims21
An amplifier arrangement comprising:
- a folded-cascode configuration including first and second transistors of complementary conductivity type, each having a main conduction path;
- constant current generating means coupled for supplying quiescent current to said folded-cascode configuration;
- means for applying an input signal to said first transistor for causing signal current flows in the main conduction paths of said first and second transistors;
- and
- load means to which said folded-cascode configuration is coupled including
- circuit means for supplying load current,
- a third transistor of like conductivity type to that of said first transistor, having its input electrode coupled for receiving a control signal, and having its main-conduction path coupled in series with said circuit means;
- and
- means for applying said control signal to condition said third transistor for conducting said load current to the output electrode of said folded-cascode configuration substantially unaffected by said input signal.
6 more elements
An amplifier arrangement comprising:
- a first folded-cascode configuration including first and second transistors of complementary conductivity type;
- a second folded-cascode configuration including third and fourth transistors of complementary conductivity type to that of said first and second transistors, respectively;
- a fifth transistor of like conductivity type to that of said first transistor, said first and fifth transistors being connected in a first long-tailed-pair configuration including means for supplying tail current thereto;
- a sixth transistor of like conductivity type to that of said third transistor, said third and sixth transistors being connected in a second long-tailed-pair configuration including means for supplying tail current thereto;
- means for applying input signals between a common connection of the respective input electrodes of said first and third transistors and a common connection of the respective input electrodes of said fifth and sixth transistors;
- means for applying a reference potential to a common connection of the input electrodes of said second and fourth transistors;
- means for connecting the respective output electrodes of said second and fourth transistors for supplying output signals therefrom;
- first and second means coupled to the main-conduction paths of said second and fourth transistors, respectively, for supplying respective quiescent currents thereto.
5 more elements
An amplifier arrangement comprising:
- first and second transistors of complementary conductivity types, each having respective output and common electrodes and a respective main conduction path therebetween, and each having a respective input electrode, the output electrode of said first transistor and the common electrode of said second transistor connecting to a common node;
- means for applying an input signal to the input electrode of said first transistor to cause a signal current flow in the main conduction path thereof;
- means for applying a reference signal to the input electrode of said second transistor;
- constant current generating means coupled to said common node for supplying quiescent current thereto;
- and
- load means for supplying a load current, to which the main conduction path of said second transistor is coupled, including
- a third transistor having output and common electrodes and a main conduction path therebetween, and having an input electrode for receiving a first control signal for establishing a load current flow in its main conduction path;
- and
- a fourth transistor of like conductivity type to that of said first transistor, having input and output electrodes and a main conduction path therebetween serially coupled with the main conduction path of said third transistor, and having an input electrode for receiving a second control signal for conditioning said fourth transistor to conduct said load current.
6 more elements
Dependencies are inferred from the claim text.