US 4,051,441 AGranted

Transistor amplifiers

AssigneeRCA Corporation

InventorCarl Franklin Wheatley, Jr.

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Abstract

The collector currents of first and second junction transistors which have base electrodes biased at the same quiescent potential and have emitter electrodes connected via respective emitter degeneration resistances to a common point, are adjusted relative to each other. This is done by applying temperature-independent currents in adjustable ratio with each other to the emitter degeneration resistances. The resistances have temperature coefficients of 1/T.sub.O to make the adjustment of the collector currents substantially unchanging for a range of temperatures around T.sub.0.

Claims6

Dependent claims

A transistor amplifier comprising:

first and second transistors of the same conductivity type, both fabricated from the same basic semiconductor material and operated at substantially the same absolute temperature T, each having an emitter-base junction between its emitter and base electrodes and a collector-base junction between its collector and base electrodes;
first and second resistive elements, each operated at substantially said temperature T, each exhibiting a positive coefficient of change in resistance of approximately 1/T.sub.0 per degree of temperature change in a range of absolute temperature including T.sub.0, said first resistive element having a first end connected to the emitter electrode of said first transistor and having a second end, said second resistive element having a first end connected to the emitter electrode of said second transistor and having a second end;
an interconnection of the second ends of said first and said second resistive elements;
means for applying substantially the same quiescent potentials to the base electrodes of said first and said second transistors, of a polarity respective to a potential at said interconnection for forward-biasing the base-emitter junction of said first and said second transistors;
means for applying a quiescent potential to the collector electrode of said first transistor of a value respective to the quiescent potential at its base electrode to prevent substantial forward conduction across the collector-base junction of said first transistor and to condition it for normal transistor operation;
means for applying a quiescent potential to the collector electrode of said transistor of a value respective to the quiescent potential at its base electrode to prevent substantial forward conduction across the collector-base junction of said second transistor and to condition it for normal transistor operation;
and
first and second sources of temperature-independent currents, at last one of which is adjustable, said first current source being connected in loop with said first resistive element and said second current source being connected in loop with said second resistive element.

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Dependencies are inferred from the claim text.

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Abstract

A transistor amplifier comprising:

first and second transistors of the same conductivity type, both fabricated from the same basic semiconductor material and operated at substantially the same absolute temperature T, each having an emitter-base junction between its emitter and base electrodes and a collector-base junction between its collector and base electrodes;
first and second resistive elements, each operated at substantially said temperature T, each exhibiting a positive coefficient of change in resistance of approximately 1/T.sub.0 per degree of temperature change in a range of absolute temperature including T.sub.0, said first resistive element having a first end connected to the emitter electrode of said first transistor and having a second end, said second resistive element having a first end connected to the emitter electrode of said second transistor and having a second end;
an interconnection of the second ends of said first and said second resistive elements;
means for applying substantially the same quiescent potentials to the base electrodes of said first and said second transistors, of a polarity respective to a potential at said interconnection for forward-biasing the base-emitter junction of said first and said second transistors;
means for applying a quiescent potential to the collector electrode of said first transistor of a value respective to the quiescent potential at its base electrode to prevent substantial forward conduction across the collector-base junction of said first transistor and to condition it for normal transistor operation;
means for applying a quiescent potential to the collector electrode of said transistor of a value respective to the quiescent potential at its base electrode to prevent substantial forward conduction across the collector-base junction of said second transistor and to condition it for normal transistor operation;
and
first and second sources of temperature-independent currents, at last one of which is adjustable, said first current source being connected in loop with said first resistive element and said second current source being connected in loop with said second resistive element.

5 more elements