Integrated circuit temperature sensor with a programmable offset

Details Integrated circuit temperature sensor with a programmable offset Integrated circuit temperature sensor with a programmable offset

1995-06-05

1996-05-21

Callahan, Timothy P.

Miscellaneous active electrical nonlinear devices, circuits, and

External effect

Temperature

327539, 307651, 323314, G05F 326

Patent

active

055193544

ABSTRACT:
An IC temperature sensor with a programmable offset generates an output voltage V.sub.o over a desired temperature range that is a PTAT voltage V.sub.PTAT shifted by an offset voltage V.sub.off. A band gap cell generates a basic PTAT voltage across a first resistor to produce a PTAT current I.sub.PTAT. A second resistor is connected from the first resistor to a reference voltage terminal to provide voltage gain. A third resistor is connected across the base-emitter junction of a transistor which is connected from the top of the second resistor to an output terminal at which V.sub.o is generated. The transistor's base-emitter voltage provides a portion of V.sub.off. The third resistor reduces the portion of I.sub.PTAT that flows through the second resistor to provide the remaining portion of V.sub.off. A current source is positioned between the transistor's emitter and the reference voltage terminal to supply its emitter current and the current for the third resistor. The offset voltage V.sub.off is set by trimming the third resistor until V.sub.o equals a voltage applied to the reference voltage terminal at a lower end of the desired temperature range. The desired gain of V.sub.PTAT is then set by trimming the first resistor.

REFERENCES:
patent: 4447784 (1984-05-01), Dobkin
patent: 4497586 (1985-02-01), Nelson
patent: 4652144 (1987-03-01), Gunther et al.
patent: 4683416 (1987-07-01), Bynum
patent: 4797577 (1989-01-01), Hing
patent: 4902959 (1990-02-01), Brokaw
patent: 5430367 (1995-07-01), Whitlock et al.
patent: 5430395 (1995-07-01), Ichimaru
Pease, "A New Fahrenheit Temperature Sensor", IEEE Journal of Solid-State Circuits, vol. SC-19, No. 6, Dec. 1984, pp. 971-977.
LM35/LM35A/LM35C/LM35CA/LM35D "Precision Centigrade Temperature Sensors", National Semi-conductor, Data Acquition Data Book, 1993, pp. 5-12 to 5-15.
LM34/LM34A/LM34C/LM34CA/LM34D "Precision Fahrenheit Temperature Sensors", National Semi-conductor, Data Acquition Data Book, 1993, pp. 5-14 to 5-8.

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