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US 4,059,793 AGranted
Semiconductor circuits for generating reference potentials with predictable temperature coefficients
AssigneeRCA Corporation
InventorAdel Abdel Aziz Ahmed
Life of this patent
Estimating the term…
Abstract
A positive-temperature-coefficient difference between the emitter-to-base potentials of two transistors in particular configuration is scaled up and added to one of the emitter-to-base potentials to develop a potential, a multiple of which is supplied as the reference potential.
Claims7
A reference potential generator comprising:
- first and second and third terminals;
- bias means for tending to increase the potential between said first and said second terminals;
- first and second transistors of the same conductivity type, each having base and emitter electrodes with a base-emitter junction therebetween and having a collector electrode, each of their emitter electrodes being directly connected without substantial intervening impedance to said first terminal;
- a first resistive element having a first end which connects to the base electrode of said first transistor and having a second end which connects to the base electrode of said second transistor and has the collector electrode of said first transistor connected thereto;
- a second resistive element having a first end connected to said second terminal and having a second end connected to the first end of said first resistive element;
- a third resistive element having a first end connected to said second terminal and having a second end connected to a third terminal and to the collector electrode of said second transistor;
- means for sensing when the potential between said first and third terminals exceeds a predetermined threshold value to decrease the potential between said first and said second terminals, thereby to generate a reference potential;
- and
- means applying between said first and said second terminals a fixed portion of said reference potential, thereby completing a feedback loop for regulating said reference potential to prescribed value.
6 more elements
A solid-state temperature-compensated voltage supply comprising:
- first and second transistors;
- a resistor connected between the base of said first transistor and the base of said second transistor;
- circuit mears for furnishing supply voltage to said two transistors to develop current flow therethrough with a current through said first transistor also flowing through said resistor;
- means for sensing the magnitude of the respective currents flowing through said two transistors;
- voltage-control means responsive to the currents sensed by said sensing means and operable to adjust the emitter potentials of said transistors to maintain the magnitude of said transistor currents at levels which provide a predetermined non-unity ratio of current densities within the two transistors responsive to which they exhibit a difference in their emitter-to-base offset potentials that is applied to said resistor connected between their bases to cause the current through said resistor to vary positively with respect to the temperature of said two transistors;
- means for developing a first voltage proportional to said resistor current and for combining said first voltage with a second voltage which varies negatively with respect to said temperature to produce a combined voltage having minimal overall variation with respect to said temperature;
- and
- output means coupled to said last named means and including an output terminal providing an output voltage proportional to said combined voltage.
5 more elements
Dependencies are inferred from the claim text.