Low-impedance voltage reference

Claim 2

A voltage reference which provides a reference voltage between a first terminal and a second termrnal at variable voltage the voltage reference comprising: a diode having a first electrode and a second electrode that form a rectifying junction; a bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor.

Claim 3

A voltage reference as in claim 1 further including at least one further diode serially coupled between the second electrode and the base in the forward conductive direction of the base-emitter junction.

Claim 4

A voltage reference as in claim 1 wherein the diode is a Schottky diode.

Claim 5

A voltage reference as in claim 3 wherein the transistor is an NPN transistor.

Claim 6

A voltage reference as in claim 4 further including a Schottky diode having its anode coupled to the node and its cathode coupled to the collector

Claim 7

A voltage reference as in claim 4 wherein the transistor lies in a semiconductor body along a surface thereof and is a vertical transistor generally oriented perpendicular to the surface.

Claim 8

A circuit comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; and a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor.

Claim 9

A circuit comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; and a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor.

Claim 10

A circuit as in claim 7 wherein the magnitude of the forward voltage across the diode when it is conductive is less than the magnitude of the forward voltage across the base-emitter junction of any of the transistors when they are also conductive.

Claim 11

A circuit as in claim 8 further including: a resistor coupled between the first terminal and the voltage supply; and a resistor coupled between the second terminal and the voltage supply.

Claim 12

A circuit as in claim 9 wherein the terminals are at variable voltages.

Claim 13

A circuit as in claim 7 wherein the diode is a Schottky diode.

Claim 14

A circuit as in claim 11 wherein the collector of the second transistor is directly connected to the voltage supply.

Claim 15

A circuit as in claim 12 further including: a resistor coupled between the first terminal and the voltage supply; and a resistor coupled between the second terminal and the voltage supply.

Claim 16

A circuit as in claim 13 further including a Schottky diode having its anode coupled to the node and its cathode coupled to the collector of the first transistor.

Claim 17

A circuit as in claim 13 wherein the terminals are at variable voltages.

Claim 18

A gate comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a Schottky diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor; at least one input diode coupled to the first terminal so as to be back-to-back with the base-emitter junction of the second transistor; and a like-polarity output bipolar transistor having a collector, an emitter coupled to a second voltage supply, and a base coupled to the emitter of the third transistor.

Claim 19

A gate comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a Schottky diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor; at least one input diode coupled to the first terminal so as to be back-to-back with the base-emitter junction of the second transistor; and a like-polarity output bipolar transistor having a collector, an emitter coupled to a second voltage supply, and a base coupled to the emitter of the third transistor.

Claim 20

A gate as in claim 16 wherein the terminals are at variable voltages.

Claim 21

A gate comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a Schottky diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor; at least one input diode coupled to the first terminal so as to be back-to-back with the base-emitter junction of the second transistor; a resistor coupled between the first terminal and the first voltage supply; a like-polarity fourth bipolar transistor having a collector, an emitter, and a base coupled to the emitter of the second transistor; a resistor coupled between the collector of the fourth transistor and the first voltage supply; and a like-polarity output bipolar transistor having a collector, an emitter coupled to a second voltage supply, and a base coupled to the emitters of the third and fourth transistors.

Claim 22

A gate comprising: a voltage reference which provides a reference voltage between a first terminal and a second terminal, the reference comprising (1) a Schottky diode having a first electrode and a second electrode that form a rectifying junction and (2) a first bipolar transistor having a collector coupled to a node between the first terminal and the first electrode, an emitter coupled to the second terminal, and a base coupled to the second electrode such that the diode is oriented in the forward conductive direction of the base-emitter junction of the transistor; a like-polarity second bipolar transistor having a collector coupled to a first voltage supply, an emitter, and a base coupled to the first terminal; a like-polarity third bipolar transistor having a collector coupled to the second terminal, an emitter, and a base coupled to the emitter of the second transistor; at least one input diode coupled to the first terminal so as to be back-to-back with the base-emitter junction of the second transistor; a resistor coupled between the first terminal and the first voltage supply; a like-polarity fourth bipolar transistor having a collector, an emitter, and a base coupled to the emitter of the second transistor; a resistor coupled between the collector of the fourth transistor and the first voltage supply; and a like-polarity output bipolar transistor having a collector, an emitter coupled to a second voltage supply, and a base coupled to the emitters of the third and fourth transistors.

Claim 23

A gate as in claim 18 wherein the collector of the second transistor is directly connected to the first voltage supply.

Claim 24

A gate as in claim 19 wherein the terminals are at variable voltages.