Integrated power detector with temperature compensation

• US 6,531,860 B1
• Filed: 06/14/2001
• Issued: 03/11/2003
• Est. Priority Date: 06/14/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Persico, Charles J., Zhou, Jianjun, Klaren, Jonathan
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): NGUYEN, TRUNG Q
• Application Number:
  US09/882,443
• Publication Number:
  US 20030042885A1
• Time in Patent Office: 635 Days
• Field of Search: 324/95, 324/600, 324/72.5, 324/760, 324/648, 324/721, 324/431, 324/441, 324/508, 324/516, 324/771, 324/133, 323/369, 323/907, 322/40, 368/203, 762/61, 762/60, 762/44, 714/14, 714/22, 714/36
• US Class Current: 324/105
• CPC Class Codes: G01R 21/14 Compensating for temperature change
• CPC Class Codes: H03G 3/04 in untuned amplifiers
• CPC Class Codes: H03G 3/3036 in high-frequency amplifiers or in frequency-changers H03G3/3052, H03G3/32, H03G3/34 take precedence

Abstract

A power detector (50) detects a power level of an amplified signal (S20) produced by a power amplifier (16) on the same integrated circuit (100). The power detector compensates for an effect of temperature variations on the magnitude of the detected power level.

Claims

1. An integrated circuit (100) comprising a power amplifier (16) configured and arranged to receive an input signal (S10) and to produce an amplified signal (S20) based on the input signal, characterized in that the integrated circuit further comprises:

a power detector (50) coupled to the power amplifier and configured and arranged to detect a power level of the amplified signal,

wherein the power detector is further configured and arranged to output a temperature-compensated indication (S30) of the power level of the amplified signal and wherein the temperature-compensation indication comprises a compensation circuit that injects a proportional to absolute temperature (PTAP) current into a compensator which produces the temperature-compensation indication.

2. The integrated circuit according to claim 1, wherein the power detector is AC coupled to the power amplifier.

3. The integrated circuit according to claim 1, wherein the power detector comprises a detecting circuit (110) and a reference circuit (120).

4. The integrated circuit according to claim 3, wherein each among the detecting circuit and the reference circuit includes a nonlinear device, the two nonlinear devices (Q1 and Q2) being matched devices.

5. The integrated circuit according to claim 4, wherein the power detector further comprises a compensation circuit (130) configured and arranged to produce the temperature-compensated indication of the power level of the amplified signal.

6. The integrated circuit according to claim 5, wherein the compensation circuit comprises a buffer (210) configured and arranged to receive an output of the detecting circuit (S110) and a compensation current (S130) substantially proportional to absolute temperature over an operating temperature range of the integrated circuit.

7. The integrated circuit according to claim 5, wherein the compensation circuit comprises an operational amplifier (220).

8. The integrated circuit according to claim 5, wherein the wherein the power detector further comprises a compensation current source (140) configured and arranged to produce the compensation current.

9. The integrated circuit according to claim 5, wherein the compensation circuit receives a selected one of a plurality of compensation currents substantially proportional to absolute temperature over an operating temperature range of the integrated circuit.

10. The integrated circuit according to claim 9, wherein the wherein the power detector further comprises a plurality of compensation current sources configured and arranged to produce the plurality of compensation currents.

11. The integrated circuit according to claim 3, wherein the detecting circuit includes a nonlinear device (Q1).

12. The integrated circuit according to claim 11, wherein the nonlinear device has at least one PN junction.

13. A process of power detection comprising receiving an input signal and, within an integrated circuit (100), producing an amplified signal based on the input signal, characterized in that said process further comprises:

within the integrated circuit, detecting a power level of the amplified signal; and

within the integrated circuit, producing a temperature-compensated indication of the power level of the amplified signal proportional to absolute temperature.

14. The process of power detection according to claim 13, wherein detecting a power level of the amplified signal includes applying the amplified signal to a nonlinear device.

15. The process of power detection according to claim 13, wherein producing a temperature-compensated indication of the power level of the amplified signal includes receiving a compensation current substantially proportional to absolute temperature over an operating temperature range of the integrated circuit.

16. The process of power detection according to claim 15, wherein producing a temperature-compensated indication of the power level of the amplified signal includes receiving a detection signal.

17. The process of power detection according to claim 15, said method further comprising, within the integrated circuit, generating the compensation current.

18. The process of power detection according to claim 13, wherein producing a temperature-compensated indication of the power level of the amplified signal includes selecting one among a plurality of compensation currents substantially proportional to absolute temperature over an operating temperature range of the integrated circuit.

19. A use of an integrated circuit (100) to output a temperature-compensated indication (S30) of the power level of an amplified signal, said integrated circuit comprising a power amplifier (16) configured and arranged to receive an input signal (S10) and to produce the amplified signal (S20) based on the input signal, characterized in that the integrated circuit further comprises:

a power detector (50) coupled to the power amplifier and configured and arranged to detect a power level of the amplified signal,

wherein the power detector is further configured and arranged to output the temperature-compensated indication of the power level of the amplified signal and wherein the temperature-compensation indication comprises a compensation circuit that injects a proportional to absolute temperature (PTAP) current into a compensator which produces the temperature-compensation indication.

20. The use of an integrated circuit according to claim 19, wherein the power detector further comprises a compensation circuit (130) configured and arranged to receive a compensation current (S130) substantially proportional to absolute temperature over an operating temperature range of the integrated circuit and to produce the temperature-compensated indication of the power level of the amplified signal.