Power amplifier with digital power control and associated methods

• US 7,502,601 B2
• Filed: 12/22/2003
• Issued: 03/10/2009
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Black Sand Technologies, Inc. (Qualcomm, Inc.)
• Inventors: Dupuis, Timothy J.
• Primary Examiner(s): Nguyen; Duc M
• Application Number:
  US10/743,218
• Publication Number:
  US 20050136865A1
• Time in Patent Office: 1,905 Days
• Field of Search: 455/127.2, 455/127.4, 455/252.1, 330/250, 330/307, 330/272, 330/259, 330/278, 702/57
• US Class Current: 455/127.2
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/0244 Stepped control
• CPC Class Codes: H03F 2200/504 the supply voltage or current being continuously controlled by a controlling signal, e.g. the controlling signal of a transistor implemented as variable resistor in a supply path for, an IC-block showed amplifier
• CPC Class Codes: H03G 3/001 Digital control of analog signals
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals

Abstract

In a power amplifier, a serial bus interface is provided for sending and receiving information to other devices, such as a baseband controller. The power amplifier includes several control pins that can be used as a serial interface, or alternately, with a direct pin control interface. The serial bus interface can be used with digital power control techniques that provide various advantages over conventional power amplifiers.

Claims

1. A method of amplifying RF signals comprising:

providing an RF power amplifier formed on an integrated circuit;

storing a plurality of ramp profiles in the integrated circuit;

receiving one or more digital control signals containing power control data from a controller that is external to the integrated circuit, wherein the control signals are received over a digital interface; and

selecting one of the ramp profiles using a digital signal processor to vary the output power of the RF power amplifier based on a desired output power level relating to one or more of the digital control signals from the controller.

2. The method of claim 1, further comprising sensing one or more properties related to the integrated circuit.

3. The method of claim 2, wherein one of the one or more properties sensed is the temperature of the integrated circuit.

4. The method of claim 2, wherein one of the one or more properties sensed is the voltage of a battery.

5. The method of claim 2, wherein the ramp profile is selected based on a received power control signal and a sensed property.

6. The method of claim 1, further comprising using the selected ramp profile to generate a power control signal for controlling the output power of the RF power amplifier.

7. The method of claim 6, further comprising providing a digital to analog convener for generating the power control signal.

8. The method of claim 1, further comprising generating a clock signal for use by the digital signal processor.

9. The method of claim 8, further comprising dividing an RF input signal to generate the clock signal.

10. A method of controlling a wireless communication device comprising:

providing a baseband controller;

providing an integrated circuit having an RF power amplifier, memory, a digital interface, and an RF input, all formed using the integrated circuit;

forming a digital signal processor using the integrated circuit;

storing a plurality of ramp profiles in the memory formed using the integrated circuit;

sending a digital power control signal from the baseband controller to the integrated circuit using the digital interface, wherein the digital power control signal relates to a desired output power level;

selecting one of the plurality of ramp profiles based on the digital power control signal received from the baseband controller; and

using the selected ramp profile to control the output power of the RF power amplifier.

11. The method of claim 10, further comprising providing a digital interface between the baseband controller and the integrated circuit.

12. The method of claim 10, further comprising providing a serial interface between the baseband controller and the integrated circuit.

13. The method of claim 10, further comprising:

sensing the temperature of the integrated circuit; and

selecting the ramp profile based on the power control signal and the sensed temperature.

14. The method of claim 10, further comprising:

sensing the battery voltage of the wireless communication device; and

selecting the ramp profile based on the power control signal and the sensed battery voltage.

15. The method of claim 10, wherein the digital signal processor selects one of the plurality of ramp profiles.

16. The method of claim 10, further comprising downloading ramp profiles to the digital signal processor.

17. The method of claim 10, further comprising providing a digital to analog converter using the integrated circuit for generating a control signal based on the selected ramp profile.