Solid-state voltage reference providing a regulated voltage having a high magnitude

• US 4,352,056 A
• Filed: 12/24/1980
• Issued: 09/28/1982
• Est. Priority Date: 12/24/1980
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Cave, David L., Zobel, Don W., Harris, Steven L.
• Primary Examiner(s): BEHA JR, WILLIAM
• Application Number:
  US06/220,207
• Time in Patent Office: 643 Days
• Field of Search: 323/311-316, 323/907, 323/231, 307/310, 307/318, 330/297
• US Class Current: 323/314
• CPC Class Codes: G05F 3/265 using bipolar transistors only
• CPC Class Codes: Y10S 323/907 Temperature compensation of semiconductor

Abstract

A two transistor voltage reference circuit controls the ratio of the current densities of two transistors by a negative feedback loop. A voltage corresponding to the difference in the base-to-emitter voltages of the two transistors is developed which has a positive temperature coefficient (TC) and which is connected in series with the base-to-emitter voltage of one of the two transistors having a negative TC. The circuit parameters are selected so that the resultant combined voltage has a predetermined, composite TC. A zener diode is included in the negative feedback loop and arranged to have a TC which cancels the predetermined composite TC to develop a reference voltage having a high magnitude that has minimal variation with temperature change.

Claims

1. A voltage reference for providing an output voltage at an output terminal thereof having independently adjustable temperature coefficient and magnitude, wherein the magnitude of the output voltage is of a relatively high level, including in combination:

first and second transistors, each having emitter, base, and collector electrodes;

a negative feedback loop interconnecting said first and second transistors and the output terminal of the voltage reference, said feedback loop enabling the currents through said first and second transistors to have a predetermined non-unity ratio of current densities;

means connected to said emitter electrodes of said first and second transistors for developing a voltage having a positive temperature coefficient in response to said non-unity ratio of current densities;

said voltage having said positive temperature coefficient combining with the emitter-to-base voltage of one of said first and second transistors to produce a combined voltage in said negative feedback loop having a predetermined variation with temperature; and

further means coupled in said negative feedback loop providing a voltage having a predetermined variation with temperature which cooperates with said combined voltage to provide a reference voltage having a predetermined temperature coefficient at the output terminal of the voltage reference.

2. The voltage reference of claim 1 further including additional means connecting said base electrodes of said first and second transistors together so that equal base potentials are applied thereto.

3. The voltage reference of claim 1 further including current mirror means connected between said collector electrodes of said first and second transistors.

4. The voltage reference of claim 1 wherein said means includes a voltage divider means having two resistors with a junction therebetween, said two resistors being connected in series with said emitter electrode of one of said first and second transistors and said junction being connected to said emitter electrode of the other of said first and second transistors.

5. The voltage reference of claim 1 further including a voltage divider means coupled in said negative feedback loop and zener diode means coupled in series with said voltage divider means.

6. The voltage reference of claim 5 wherein said zener diode means includes an implanted zener diode.

8. The voltage reference supply of claim 5, further including means connecting said base electrodes of said first and second transistors together to provide equal base potentials.

7. A solid-state temperature-compensated voltage reference supply for providing a regulated voltage having a high magnitude, comprising:

first and second transistors each having emitter, base and collector electrodes;

resistive means connected between said emitter electrodes of said first and second transistors;

conductor means for furnishing supply potentials to said first and second transistors to develop current flow therethrough;

means for sensing the magnitudes of the respective currents flowing through said first and second transistors;

amplifier means coupled to said base electrodes of said first and second transistors and responsive to said means for sensing to adjust the base potentials of said transistors to maintain the magnitudes of said transistor currents at levels which provide a predetermined non-unity ratio of current densities within said first and second transistors to thereby cause the current through said resistive means to vary positively with respect to the temperature of said first and second transistors;

means for developing a first voltage proportional to said current of said resistive means and for combining said first voltage with a second voltage which varies negatively with temperature to produce a combined voltage having a predetermined variation with temperature;

a voltage-dividing network including a zener diode, said zener diode providing a third voltage having a further variation with temperature which substantially cancels said predetermined variation with temperature of said second voltage, said voltage-dividing network being coupled to the output terminal of said amplifier means and further having a network terminal providing a voltage reference which is a predetermined fraction of the output voltage of the amplifier means to enable said voltage reference supply to provide an output voltage having a high magnitude; and

means coupling said network terminal to the base electrodes of said first and second transistors.

9. The solid state temperature compensated voltage reference supply of claim 7 wherein said zener diode includes an implanted zener diode.

10. A solid state temperature-compensated voltage supply for providing a regulated output voltage, comprising:

first and second transistors each having emitter, base and collector electrodes;

resistive means having first and second ends, said first end being connected to said emitter electrode of said first transistor, said second end being connected to said emitter electrode of said second transistor;

feedback means coupled between said collector electrodes and said base electrodes of said first and second transistors, said feedback means being responsive to said collector currents of said first and second transistors and operable to adjust the base potentials of said first and second transistors to maintain the magnitudes of the emitter currents of said first and second transistors at levels which provide a predetermined non-unity ratio of emitter current densities between said first and second transistors to thereby cause the current through said resistive means to vary positively with respect to the temperature of said first and second transistors;

circuit means for developing a first voltage proportional to said current through said resistive means and for combining said first voltage with a second voltage which varies negatively with respect to temperature to provide a combined voltage having a predetermined variation with respect to temperature; and

further circuit means coupled to said circuit means, said further circuit means providing a third voltage having a further variation with temperature which substantially cancels said predetermined variation with temperature of said combined voltage, said further circuit means enabling the voltage supply to provide a temperature compensated regulated output voltage.

11. The voltage supply of claim 10 wherein said feedback means includes an amplifier and a voltage divider, and said further circuit means includes a zener diode coupled in series with said voltage divider.

12. The voltage supply of claim 11 wherein said zener diode includes an implanted zener diode.