Granted Patent B2

US 7,720,448 · App. 10/748,735 · Granted May 18, 2010

Abstract

Claims (39)

1. A system for use in a portable communications device comprising:

a digital signal processor (DSP) for processing a digital source input and providing a digital processed bit stream;

a digital-to-analog converter (DAC) for converting the digital processed bit stream and providing at least one analog signal; and

a power management controller within the DSP configured to control power consumption of the portable communications device and for interpreting a plurality of control parameters and dynamically adjusting a bias current used by the DAC based on minimal signal requirements of the at least one analog signal,

wherein the control parameters include reference capacitance requirements for a predetermined slew rate.

2. A system as in claim 1 , wherein the control parameters further include one or more of a digital multiple access protocol (MA), noise requirements, and intermodulation distortion (IMD).

3. A system as in claim 1 , further comprising:

at least one DAC filter for adjusting the at least one analog signal to a desired frequency response.

4. A system as in claim 3 , further comprising:

a mixer for providing an intermediate frequency (IF) signal from the at least one analog signal; and

a power amplifier for amplifying the IF signal from the mixer.

5. A system as in claim 4 , wherein the bias current of the DAC filter, mixer and power amplifier can be dynamically controlled by the power management controller in order to minimize current drain of the portable communications device.

6. A Previously Presented system as in claim 4 , wherein the IF signal operates at radio frequency (RF).

7. A system as in claim 4 , wherein the power management controller is further for adjusting control parameters of the DAC, the at least one DAC filter, the mixer and the power amplifier based upon digital protocol received by the DSP and analog signal requirements for the portable communications device.

8. A system as in claim 4 , wherein the power management controller dynamically adjusts the bias current used by the DAC based upon one or more of a digital multiple access protocol (MA), noise requirements, and intermodulation distortion (IMD) requirements of the portable communications device.

9. A system as in claim 4 , wherein one or more control parameters for, respectively, the DAC, the at least one DAC filter, the mixer and the power amplifier may be independently controlled.

10. A system as in claim 4 , wherein the power management controller further controls supply bias to an audio processing system in a receiver of the portable communications device.

11. A power management control system for use with signal generation components in a portable communications device comprising:

a digital signal processor (DSP) for processing a digital bit stream and providing a processed digital signal therefrom;

a digital-to-analog converter (DAC) for converting the processed digital signal and providing a modulated analog signal;

at least one DAC filter for controlling the frequency response of the modulated analog signal to produce a filtered signal;

a mixer for mixing the filter signal with at least one local oscillator signal to produce an intermediate frequency (IF) signal;

a power amplifier for amplifying the IF signal; and

a power management controller located within the DSP for adjusting the control parameters of the DAC, at least one DAC filter, mixer and power amplifier based upon digital protocol received by the DSP and minimum analog signal requirements specified by the portable communications device,

wherein the adjusting control parameters include adjusting supply bias based upon reference capacitance requirements for achieving a predetermined slew rate.

12. A power management control system as in claim 11 , wherein the adjusting control parameters further include adjusting supply bias based upon one or more of a determination of a digital multiple access protocol (MA), system noise requirements, and intermodulation distortion (IMD) requirements.

13. A power management control system as in claim 11 , wherein control parameters for the DAC, the at least one DAC filter, mixer and power amplifier may be independently controlled.

14. A power management control system as in claim 11 , wherein the power management controller further controls supply bias to an audio processing system in a receiver of the portable communications device.

15. A method for managing power to a communications system having at least one digital-to-analog converter (DAC) comprising the steps of:

initializing the components used within a portable communications system;

receiving an incoming digital input stream at a digital signal processor (DSP);

determining the digital multiple access protocol (MA) used in the digital input stream;

generating a processed digital signal from the DSP;

converting the processed digital signal to an analog signal using a DAC; and

controlling a supply bias used by the DAC based upon a reference capacitance in the DAC for controlling slew rate, the MA, and one or more of noise requirements and intermodulation requirements of the portable communications system.

16. A method for managing power to a communications system utilizing a DAC as in claim 15 , wherein the supply bias is controlled by a power management controller in the DSP.

17. A method for managing power to a communications system utilizing a DAC as in claim 16 , wherein the power management controller can adjust the reference capacitance in the DAC for controlling slew rate.

18. A method for managing power to a communications system utilizing a DAC as in claim 17 , wherein the reference capacitance controls noise and slew rate.

19. A method for managing power to a communications system utilizing a DAC as in claim 15 , wherein the DAC is in an audio processing system.

Assignments (17)