CONTROLLER AND METHOD FOR USING A DC-DC CONVERTER IN A MOBILE HANDSET

• US 20120064953A1
• Filed: 09/12/2011
• Published: 03/15/2012
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Dagher, Elias, Juan, Kevin, Ku, Man H., Rozenblit, Dmitriy
• Granted Patent: US 8,639,200 B2
• Time in Patent Office: Days
• US Class Current: 455/571
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A controller enables the integration of a DC-DC converter in an amplitude modulation power control loop in a mobile handset. The controller includes an input conditioner and an event sensor. The input conditioner uses a peak detector to track the output of a regulator and responds to available baseband input signals. The event sensor controls a switch that connects the DC-DC converter to a battery in response to a bypass event. The controller bypasses the DC-DC-converter when a transmitter is not enabled. The DC-DC converter is enabled prior to a transmission burst. A target voltage is determined from a series of detected peak voltages from the output of the regulator. The controller commands the DC-DC converter to transition to the target voltage until the end of a transmission burst.

Claims

1. A method for using a DC-DC converter in a mobile handset, comprising:

applying a DC-DC converter between a voltage source and a regulator, the regulator having an output connected to a power amplifier;

enabling the DC-DC converter in response to a transmission burst;

detecting a plurality of peaks from the regulator output;

determining a target voltage in response to the plurality of peaks;

commanding the DC-DC converter to transition to the target voltage; and

commanding the DC-DC converter to a bypass mode in response an end of the transmission burst.

2. The method of claim 1 wherein commanding the DC-DC converter to the bypass mode includes coupling the DC-DC converter to a battery, the battery providing a battery voltage.

3. The method of claim 1 wherein enabling the DC-DC converter includes responding to a transmitter switch signal.

4. The method of claim 1 wherein detecting the plurality of peaks from the regulator output includes coupling the output of the regulator to a peak detector.

5. The method of claim 4 further comprising:

waiting a desired time for the peak detector to settle.

6. The method of claim 5 wherein waiting a desired time includes using an adjustable delay element.

7. The method of claim 5 wherein waiting a desired time includes waiting for a predetermined time.

8. The method of claim 1 wherein determining the target voltage includes determining a target voltage that is higher than a function of the plurality of peaks.

9. The method of claim 8 further comprising:

commanding the DC-DC converter to the bypass mode when a magnitude of a peak in the regulator output exceeds the target voltage.

10. The method of claim 1 wherein commanding the DC-DC converter to the bypass mode includes commanding the DC-DC converter in response to a pedestal voltage.

11. The method of claim 10 wherein the pedestal voltage is associated with a regulator input signal.

12. The method of claim 2 wherein determining the target voltage further includes limiting the voltage gap between the battery voltage and the target voltage.

13. The method of claim 1 further comprising:

using the steps of commanding the DC-DC converter in a bypass mode, enabling, detecting, determining and commanding the DC-DC converter to transition to the target voltage to communicate a multi-slot transmission burst with amplitude modulation.

14. The method of claim 1 further comprising:

commanding the DC-DC converted in the bypass mode when a transmitter is not enabled.

15. A power amplifier controller, comprising:

an input conditioner connected to a regulator and a DC-DC converter, the input conditioner including a peak detector responsive to an output of the regulator and a mode selector responsive to input signals from a baseband subsystem; and

an event sensor configured to direct coupling between a voltage source and the DC-DC converter in response to a bypass event.

16. The controller of claim 15 wherein the input conditioner further includes an offset for determining a target voltage that is higher than a function of a series of peak voltages detected by the peak detector.

17. The system of claim 16 wherein the bypass event includes a peak voltage that exceeds the target voltage.

18. The system of claim 16 wherein the bypass event includes a signal condition indicative of an end of a transmission burst.

19. The controller of claim 15 wherein the input conditioner further includes a low-voltage limiter configured to limit the voltage gap between the battery voltage and a target voltage.

20. The controller of claim 15 further comprising:

a switching node for controlling the frequency of the output from the DC-DC converter.

21. The controller of claim 15 wherein the mode selector is responsive to an under voltage lockout detector.

22. A wireless device, comprising:

a transmitter circuit;

a receiver circuit;

an antenna configured to transmit signals from the transmitter circuit and to receive signals for the receiver circuit;

a power amplifier configured to amplify at least some of the signals, the power amplifier being powered via a DC-DC converter and a regulator; and

a power amplifier controller having an input conditioner and an event sensor, the input conditioner connected to the regulator and the DC-DC converter and including a peak detector responsive to an output of the regulator and a mode selector responsive to input signals from a baseband subsystem, the event sensor configured to direct coupling between a voltage source and the DC-DC converter in response to a bypass event.

23. An input conditioner module for using a DC-DC converter in a mobile handset, the input conditioner comprising:

a mode selector configured to be responsive to input signals from a baseband system; and

a peak detector configured to be responsive to a regulator output.