Back to results
US 3,942,046 AGranted
Low output impedance voltage divider network
AssigneeRCA Corporation
InventorAllen LeRoy Limberg
Life of this patent
Estimating the term…
Abstract
A low output impedance precision dynamic voltage divider network having low power dissipation and particularly suited for fabrication on a monolithic integrated circuit chip.
Claims15
A dynamic potential divider having first and second terminals for application of potentials and a third terminal to provide intermediate potential output comprising:
- first and second resistors;
- a first transistor having an emitter electrode coupled by said first resistor to said first terminal, a collector electrode direct current conductively coupled to said second terminal by a first current path including said second resistor, a base electrode, and a base-emitter junction between said base and emitter electrodes to be maintained in forward bias to permit common-emitter amplifier operation thereof;
- third and fourth resistors in series connection, their interconnection with each other being direct current conductively coupled to said base electrode of said first transistor by a third current path, the end of said fourth resistor remote from said interconnection returned to said first terminal;
- and
- a second transistor having an emitter electrode direct current conductively coupled to said interconnection by means including said third resistor, a collector electrode direct current conductively coupled to said second terminal, a base electrode direct current conductively coupled to the collector electrode of said first transistor, whereby a second current path is established between the collector of said first transistor and the end of the third resistor remote from said interconnection, and a base-emitter junction between its said base and emitter electrodes to be maintained in forward bias to permit operation as a common-collector amplifier stage, said third terminal being connected at a point in the recited circuitry coupling the collector and base electrodes of said first transistor;
- the ratio of the resistance of said second resistor to that of said first resistor being a positive number equal to the sum of (1) the number of forward biased semiconductor junctions in said first current path;
- (2) the number of forward biased semiconductor junctions in said second current path;
- (3) the number of forward biased semiconductor junctions in said third current path;
- and (4) the number of forward biased semiconductor junctions in said third current path multiplied by the ratio of the resistances of said third resistor to said fourth resistor, whereby the potential at the base electrode of said first transistor is rendered substantially independent of variations in the offset potentials of said forward biased semiconductor junctions caused by temperature changes.
6 more elements
A dynamic potential divider network having first and second terminals for application of a source of potential and a third terminal to provide intermediate potential output comprising:
- a first transistor having emitter, base and collector electrodes;
- first and second resistors, said first resistor coupling the emitter electrode of said first transistor to said first terminal, said second resistor coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal, the base of said second transistor being coupled to the collector of said first transistor;
- third and fourth resistors coupled in series, their common connection being coupled to the base electrode of said first transistor, the end of said fourth resistor remote from said common connection being coupled to said first terminal, the end of said third resistor remote from said common connection being connected to the emitter of said second transistor;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU32## for providing an output voltage greater than one-half of said source of potential between said third and first terminals, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor, said output voltage being independent of temperature and being a predetermined portion of said source of potential according to said resistor ratios.
3 more elements
A dynamic potential divider network having first and second terminals for application of a source of potential and a third terminal to provide intermediate potential output and comprising:
- a first transistor having emitter, base and collector electrodes;
- first and second resistors, said first resistor coupling the emitter electrode of said first transistor to said first terminal, said second resistor coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal;
- third and fourth resistors coupled in series, their common connection being coupled to the base electrode of said first transistor, the end of said fourth resistor remote from said common connection being coupled to said first terminal, the end of said third resistor remote from said common connection being connected to the emitter of said second transistor;
- a third transistor having emitter, base and collector electrodes, the collector electrode of said third transistor being coupled to said second terminal, the emitter electrode being coupled to the base of said second transistor and means coupling said emitter electrode of said third transistor to said first terminal, the base electrode of said third transistor being coupled to the collector electrode of said first transistor;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU33## for providing an output voltage greater than one-half of said source of potential between said third and first terminals, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor.
4 more elements
A dynamic potential divider network having first and second terminals for application of potentials and a third terminal to provide intermediate potential output and comprising:
- a first transistor having emitter, base and collector electrodes;
- first and second resistors, said first resistor coupling the emitter electrode of said first transistor to said first terminal, said second resistor coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal, the base of said second transistor being coupled to the collector of said first transistor;
- third and fourth resistors coupled in series to provide a common connection, the end of said fourth resistor remote from said common connection being coupled to said first terminal, the end of said third resistor remote from said common connection being connected to the emitter of said second transistor;
- a third transistor having emitter, base and collector electrodes, the collector electrode of said third transistor being coupled to said second terminal, the emitter of said third transistor being coupled to the base of said first transistor and means coupling the emitter of said third transistor to said first terminal, the base electrode of said third transistor being coupled to the common connection of said third and fourth resistor;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU34## for providing an output voltage greater than one-half of said source of potential between said third and first terminal, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor.
4 more elements
A dynamic potential divider network having first and second terminals for application of a source of potential and a third terminal to provide intermediate potential output comprising:
- a first transistor having emitter, base and collector electrodes;
- a first resistor coupling the emitter electrode of said first transistor to said first terminal;
- means including a second resistor coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal, the base of said second transistor being coupled to the collector of said first transistor;
- voltage divider means, including third and fourth resistors having a common connection and two remote ends, said common connection being coupled to the base electrode of said first transistor, the first remote end of said voltage divider means being coupled to said first terminal, the second remote end of said voltage divider means being connected to the emitter of said second transistor for providing a portion of the voltage appearing between the emitter of said second transistor and said first terminal;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU35## for providing an output voltage greater than one-third of said source of potential between said third and first terminals, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor, said output voltage being independent of temperature and being a predetermined portion of said source of potential according to said resistor ratios.
4 more elements
A dynamic potential divider network having first and second terminals for application of a source of potential and a third terminal to provide intermediate potential output comprising:
- a first transistor having emitter, base and collector electrodes;
- a first resistor coupling the emitter electrode of said first transistor to said first terminal;
- means including a second resistor and a diode serially coupled thereto coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal, the base of said second transistor being coupled to the collector of said first transistor;
- voltage divider means, including third and fourth resistors having a common connection and two remote ends, said common connection being coupled to the base electrode of said first transistor, the first remote end of said voltage divider means being coupled to said first terminal, the second remote end of said voltage divider means being connected to the emitter of said second transistor for providing a portion of the voltage appearing between the emitter of said second transistor and said first terminal;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU36## for providing an output voltage greater than one-third of said source of potential between said third and first terminals, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor, said output voltage being independent of temperature and being a predetermined portion of said source of potential according to said resistor ratios.
4 more elements
A dynamic potential divider network having first and second terminals for application of a source of potential and a third terminal to provide intermediate potential output comprising:
- a first transistor having emitter, base and collector electrodes;
- a first resistor coupling the emitter electrode of said first transistor to said first terminal;
- means including a second resistor coupling the collector electrode of said first transistor to said second terminal;
- a second transistor having emitter, base and collector electrodes, the collector electrode of said second transistor being coupled to said second terminal, the base of said second transistor being coupled to the collector of said first transistor;
- voltage divider means, including third and fourth resistors having a common connection and two remote ends, and a diode serially coupled with said third resistor, coupled between the emitter of said second transistor and said common connection, said fourth resistor being coupled between said common connection and said first terminal, said common connection being coupled to the base electrode of said first transistor, the first remote end of said voltage divider means being coupled to said first terminal, the second remote end of said voltage divider means being connected to the emitter of said second transistor for providing a portion of the voltage appearing between the emitter of said second transistor and said first terminal;
- and
- said first, second, third, and fourth resistors being selected according to the expressions, ##EQU37## for providing an output voltage greater than one-third of said source of potential between said third and first terminals, said third terminal being coupled to a point in the circuit path between the collector and base electrodes of said first transistor, said output voltage being independent of temperature and being a predetermined portion of said source of potential according to said resistor ratios.
4 more elements
Dependencies are inferred from the claim text.