Method and circuit for base current compensation
AssigneeTexas Instruments Incorporated
InventorsDavid A. Gammie, Jeffery B. Parfenchuck, Jerry L. Doorenbos
Life of this patent
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Abstract
A base current compensation circuit is configured for injecting base current to the base of a transistor device to compensate for the lost current demanded by a transistor base. The base current compensation circuit is configured to inject current into the base of the transistor without the headroom requirements, as well as being less complex than other approaches. An exemplary base current compensation circuit comprises a sampling circuit and a current mirror feedback circuit configured for providing multiples of the base current demanded by the transistor device.
Claims25
An integrated circuit comprising:
- a supply voltage terminal;
- an amplifier circuit comprising at least one transistor having a base terminal configured to receive a base current;
- and
- a base current compensation circuit coupled to said supply voltage terminal and said amplifier circuit, said base current compensation circuit configured for compensation of losses in said base current of said at least one transistor through injection of a compensation current at a compensation node coupled to said base terminal.
An amplifier circuit configured with a base current compensation circuit for reducing losses in the base current of a transistor in said amplifier circuit, said base current compensation circuit comprising:
- a current mirror circuit coupled to said amplifier circuit;
- a sampling circuit configured to sample multiples of the base current for injecting a compensation current, said sampling circuit coupled with said current mirror circuit to said amplifier circuit, said sampling circuit comprising a first sampling component and a second sampling component;
- and
- a compensation node coupled to a base terminal of the transistor of said amplifier circuit, wherein said base current compensation circuit is configured for compensation of losses in said base current through injection of said compensation current into said compensation node.
A base current compensation circuit for compensating for losses in base current in a transistor in an amplifier circuit, said base current compensation circuit comprising:
- a sampling circuit configured to sample multiples of the base current for injecting a compensation current, said sampling circuit comprising a first sampling component for sampling and a second sampling component, said first sampling component configured for sampling collector current of the transistor of the amplifier circuit, and said second sampling component is configured for sampling base current of the transistor of the amplifier circuit;
- and
- wherein said base current compensation circuit is configured for compensation of losses in the base current through injection of a compensation current into a compensation node.
A method for compensation of losses in base current of a transistor within an amplifier circuit, said method comprising the steps of:
- sampling a collector current of said transistor in a first sampling component;
- mirroring said sampled collector current to a second sampling component;
- sampling a base current of said transistor in said second sampling component;
- and
- injecting a compensation current comprising a multiple of the base current of said transistor into a compensation node coupled to the base of said transistor.
Dependencies are inferred from the claim text.