TEMPERATURE COMPENSATION CIRCUIT

• US 20100176869A1
• Filed: 01/13/2010
• Published: 07/15/2010
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Horie, Koji, Nagata, Minoru
• Granted Patent: US 8,212,605 B2
• Time in Patent Office: Days
• US Class Current: 327/513
• CPC Class Codes: H03F 1/302 in bipolar transistor amplifiers H03F1/303, H03F1/305, H03F1/307 take precedence
• CPC Class Codes: H03F 2200/447 the amplifier being protected to temperature influence
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/245 with semiconductor devices only

Abstract

A temperature compensation circuit according to an embodiment of the present invention includes a bias circuit configured to output a bias current having a current value increasing in proportion to an absolute temperature in a low-temperature region in which a temperature is lower than a predetermined temperature, and having a greater current value than the current value proportional to the absolute temperature in a high-temperature region in which the temperature is equal to or greater than the predetermined temperature, and a transistor having a control terminal supplied with the bias current. The bias circuit includes a first current generating circuit configured to generate a first current increasing in proportion to the absolute temperature, a second current generating circuit configured to generate a second current that does not flow in the low-temperature region and flows in the high-temperature region, and a control circuit configured to control the second current and having a connection terminal capable of being connected with an external resistor for adjusting a magnitude of the second current, and is configured to generate a third current by adding the first current to the second current, and output the bias current depending on or equal to the third current.

Claims

1. A temperature compensation circuit comprising:

a bias circuit configured to output a bias current having a current value increasing in proportion to an absolute temperature in a low-temperature region in which a temperature is lower than a predetermined temperature, and having a greater current value than the current value proportional to the absolute temperature in a high-temperature region in which the temperature is equal to or greater than the predetermined temperature; and

a transistor having a control terminal supplied with the bias current,

the bias circuit comprising;

a first current generating circuit configured to generate a first current increasing in proportion to the absolute temperature;

a second current generating circuit configured to generate a second current that does not flow in the low-temperature region and flows in the high-temperature region; and

a control circuit configured to control the second current and having a connection terminal capable of being connected with an external resistor for adjusting a magnitude of the second current,

the bias circuit being configured to generate a third current by adding the first current to the second current, and output the bias current that is the third current or a fourth current depending on the third current.

2. The compensation circuit according to claim 1, wherein

the control circuit is configured to control the first and second currents, and

a magnitude of the first current and the magnitude of the second current are capable of being adjusted by the external resistor.

3. The compensation circuit according to claim 1, wherein

only the magnitude of the second current is capable of being adjusted by the external resistor, with respect to a magnitude of the first current and the magnitude of the second current.

4. The compensation circuit according to claim 1, wherein

a height of the predetermined temperature is capable of being adjusted by adjusting the second current with the external resistor.

5. The compensation circuit according to claim 1, wherein

the transistor further includes a first main terminal connected to a power supply terminal, and a second main terminal connected to a ground line to output an output current, and is configured to serve as a power amplifier.

6. The compensation circuit according to claim 1, wherein

the second current generating circuit comprises a differential amplifier configured to generate the second current.

7. A temperature compensation circuit comprising:

a bias circuit configured to output a bias current having a current value increasing in proportion to an absolute temperature in a low-temperature region in which a temperature is lower than a predetermined temperature, and having a greater current value than the current value proportional to the absolute temperature in a high-temperature region in which the temperature is equal to or greater than the predetermined temperature; and

a transistor having a control terminal supplied with the bias current,

the bias circuit comprising;

a first transistor having a control terminal supplied with a first control current or voltage having a current value or a voltage value changing linearly with respect to the absolute temperature;

a second transistor having a control terminal supplied with a second control current or voltage having a current value or a voltage value independent of the absolute temperature;

a third transistor having a control terminal supplied with a third control current or voltage having a current value or a voltage value changing linearly with respect to the absolute temperature;

a fourth transistor having a control terminal supplied with a fourth control current or voltage having a current value or a voltage value changing linearly with respect to the absolute temperature, and having a main terminal through which a first current flows, the first current increasing in proportion to the absolute temperature;

a fifth transistor having a control terminal connected to the main terminal of the second transistor, a first main terminal connected to the main terminal of the third transistor, and a second main terminal;

a sixth transistor having a control terminal connected to the main terminal of the first transistor, a first main terminal connected to the main terminal of the third transistor, and a second main terminal through which a second current flows, the second current not flowing in the high-temperature region and flowing in the low-temperature region; and

a control circuit configured to supply the third control current or voltage to the third transistor, and having a connection terminal capable of being connected with an external resistor for adjusting a magnitude of the second current,

the bias circuit being configured to generate a third current by adding the first current to the second current, and output the bias current that is the third current or a fourth current depending on the third current.

8. The compensation circuit according to claim 7, wherein

the control circuit is configured to supply the third and fourth control currents or voltages to the third and fourth transistors, respectively, and

a magnitude of the first current and the magnitude of the second current are capable of being adjusted by the external resistor.

9. The compensation circuit according to claim 7, wherein

the control circuit is configured to output a fifth control current or voltage having a current value or a voltage value changing linearly with respect to the absolute temperature,

the control circuit is configured to supply the third control current or voltage depending on the fifth control current or voltage to the third transistor, and

the control circuit is configured to supply the fourth control current or voltage depending on the fifth control current or voltage to the fourth transistor.

10. The compensation circuit according to claim 7, wherein

the transistor supplied with the bias current further includes a first main terminal connected to a power supply terminal, and a second main terminal connected to a ground line to output an output current, and is configured to serve as a power amplifier.

11. The compensation circuit according to claim 7, wherein the first control voltage is a bandgap voltage.

12. The compensation circuit according to claim 7, wherein the bias circuit further comprises:

a diode having an anode connected to the main terminals of the first and second transistors, and a cathode connected to a ground line.

13. The compensation circuit according to claim 7, wherein the bias circuit further comprises:

a first resistor provided between the first transistor and the diode;

a second resistor provided between the second transistor and the diode; and

a third resistor provided between the first and second resistors and the diode.

14. The compensation circuit according to claim 13, wherein

the control terminal of the sixth transistor is connected to a first node located between the main terminal of the first transistor and the first resistor, and

the control terminal of the fifth transistor is connected to a second node located between the main terminal of the second transistor and the second resistor.

15. The compensation circuit according to claim 14, wherein

a potential at the first node is kept constant irrespective of the temperature, and

a potential at the second node changes linearly with respect to the absolute temperature.

16. The compensation circuit according to claim 7, wherein the bias circuit further comprises:

a fourth resistor connected between the third transistor and a ground line; and

a fifth resistor connected between the fourth transistor and the ground line.

17. The compensation circuit according to claim 7, wherein the bias circuit further comprises:

a seventh transistor having a main terminal connected to the main terminal of the fourth transistor and the second main terminal of the sixth transistor;

an eighth transistor having a control terminal connected to a control terminal of the seventh transistor;

a ninth transistor having a control terminal connected to a main terminal of the eighth transistor, and a main terminal connected to the control terminal of the transistor supplied with the bias current; and

a tenth transistor having a control terminal connected to the main terminal of the ninth transistor, and a main terminal connected to the control terminal of the ninth transistor.

18. The compensation circuit according to claim 17, wherein the bias circuit further comprises:

a sixth resistor connected between the control terminal of the ninth transistor and the main terminal of the tenth transistor; and

a seventh resistor connected between the sixth resistor and the control terminal of the transistor supplied with the bias current.

19. The compensation circuit according to claim 7, wherein the control circuit comprises:

an operational amplifier having a first input terminal supplied with a voltage changing linearly with respect to the absolute temperature, and a second input terminal connected to the connection terminal;

an eleventh transistor having a control terminal connected to an output terminal of the operational amplifier, and a main terminal connected to the connection terminal;

a twelfth transistor having a control terminal connected to the output terminal of the operational amplifier;

a thirteenth transistor having a main terminal connected to a main terminal of the twelfth transistor, and control terminal connected connected to the control terminals of the third and fourth transistors; and

a fourteenth transistor having a control terminal connected to the main terminal of the thirteenth transistor, and a main terminal connected to the control terminal of the thirteenth transistor.

20. The compensation circuit according to claim 19, wherein the control circuit further comprises:

an eighth resistor connected between the first input terminal of the operational amplifier and a ground line; and

a ninth resistor connected between the thirteenth transistor and the ground line.