Average power tracking controller

Patent metadata

Field	Value
Publication number	US-9280163-B2
Application number	US-201313747725-A
Country	US
Kind code	B2
Filing date	Jan 23, 2013
Priority date	Dec 1, 2011
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

First claim

What is claimed is:

1. A radio frequency (RF) switching converter comprising:
a switching circuit operable to receive a power source voltage, the switching circuit being switchable so as to generate a pulsed output voltage from the power source voltage;
an RF filter coupled to receive the pulsed output voltage from the switching circuit and operable to convert the pulsed output voltage from the switching circuit into a supply voltage having a supply voltage level with a ripple variation;
a bang-bang controller (BBC) operable to receive an Average Power Tracking (APT) signal and configured to switch the switching circuit based on an APT signal level of the APT signal so that the switching circuit generates the pulsed output voltage and so that the supply voltage level of the supply voltage has an average DC supply voltage level set in accordance with a DC offset signal level of the APT signal; and
an APT controller operable to receive a supply control input signal having a supply control input signal level, the APT controller being configured to:
generate the APT signal such that the APT signal level varies from the DC offset signal level of the APT signal in accordance with the ripple variation of the supply voltage level of the supply voltage; and
set the DC offset signal level of the APT signal in accordance with the supply control input signal level of the supply control input signal.

2. The RF switching converter of claim 1 wherein:
the supply control input signal level is indicative of a target DC supply voltage level for the average DC supply voltage level; and
the APT controller is configured to set the DC offset signal level of the APT signal in accordance with the supply control input signal level of the supply control input signal so that the average DC supply voltage level is driven by the BBC to the target DC supply voltage level.

3. The RF switching converter of claim 1 wherein the APT controller is further operable to receive a feedback signal having a feedback signal level that is indicative of the supply voltage level of the supply voltage and is configured to:
generate the APT signal from the feedback signal such that the APT signal level corresponds with the feedback signal level of the feedback signal and the APT signal level is provided at the DC offset signal level when the feedback signal level of the feedback signal is provided at a feedback voltage magnitude; and
set the DC offset signal level of the APT signal by establishing the feedback voltage magnitude in accordance with the supply control input signal level of the supply control input signal.

4. The RF switching converter of claim 3 wherein the APT controller is further configured to establish the feedback voltage magnitude as being equal to the supply control input signal level of the supply control input signal.

5. The RF switching converter of claim 1 wherein the APT controller comprises an amplification circuit having an amplification gain, wherein the amplification circuit is operable to receive the supply control input signal and to receive a feedback signal having a feedback signal level indicative of the supply voltage level of the supply voltage, the amplification circuit being configured to:
set the DC offset signal level of the APT signal in accordance with the supply control input signal level of the supply control input signal by generating an error signal having an error signal level set in accordance with a difference between the feedback signal level and the supply control input signal level; and
generate the APT signal from the error signal by amplifying the error signal level in accordance with the amplification gain.

6. The RF switching converter of claim 5 wherein generating the error signal having the error signal level set in accordance with the difference between the feedback signal level and the supply control input signal level provides the DC offset signal level as a quiescent APT signal level of the APT signal when the error signal level is zero.

7. The RF switching converter of claim 5 wherein:
the feedback signal is a feedback voltage and the feedback signal level is a feedback voltage level;
the supply control input signal is a supply control input voltage and the supply control input signal level is a supply control input voltage level;
the error signal is an error voltage and the error signal level is an error voltage level; and
the amplification gain of the amplification circuit is a transconductance gain so that the APT signal is an APT current, the APT signal level is an APT current level, and the DC offset signal level of the APT signal is a DC offset current level.

8. The RF switching converter of claim 7 wherein the difference is from the feedback voltage level to the supply control input voltage level.

9. The RF switching converter of 8 wherein the transconductance gain has a negative value.

10. The RF switching converter of claim 9 wherein:
the switching circuit is switchable so as to provide the pulsed output voltage in a first voltage state, a second voltage state that is higher than the first voltage state, and a third voltage state that is higher than the second voltage state; and
the BBC is operable in a first bang-bang mode and in a second bang-bang mode, the BBC being configured to:
generate a sense voltage from the APT current such that a sense voltage level of the sense voltage is directly proportional to the APT signal level of the APT signal;
generate a first threshold voltage having a first threshold voltage level and a second threshold voltage having a second threshold voltage level that is higher than the first threshold voltage level;
in the first bang-bang mode, switch the switching circuit to change the pulsed output voltage from the first voltage state to the second voltage state in response to the sense voltage level being above the second threshold voltage level;
in the first bang-bang mode, switch the switching circuit to change the pulsed output voltage from the second voltage state to the first voltage state in response to the sense voltage level of the sense voltage being below the first threshold voltage level;
in the second bang-bang mode, switch the switching circuit to change the pulsed output voltage from the second voltage state to the third voltage state in response to the sense voltage level being above the second threshold voltage level; and
in the second bang-bang mode, switch the switching circuit to change the pulsed output voltage from the third voltage state to the second voltage state in response to the sense voltage level of the sense voltage being below the first threshold voltage level.

11. The RF switching converter of claim 10 wherein the first voltage state is set near ground, the second voltage state is set near a power source voltage level of the power source voltage, and the third voltage state is set so as to be boosted with respect to the power source voltage level of the power source voltage.

12. The RF switching converter of claim 1 wherein the APT controller is further configured to generate the APT signal such that a first change in the supply voltage level of the supply voltage results in a second change in the APT signal level, the second change being negatively proportional to the first change.

13. The RF switching converter of claim 12 wherein:
the switching circuit is switchable so as to provide the pulsed output voltage in a first voltage state, a second voltage state that is higher than the first voltage state, and a third voltage state that is higher than the second voltage state; and
the BBC is operable in a first bang-bang mode and in a

Assignees

• Rf Micro Devices Inc

Inventors

• Kay Michael R
• Khlat Nadim

Classifications

• G05F1/46 Primary

  wherein the variable actually regulated by the final control device is DC (G05F1/625 takes precedence) · CPC title

• H03F2200/351

  Pulse width modulation being used in an amplifying circuit · CPC title

• H02M2001/0067

  Electricity · mapped topic

• H03F2200/504

  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 title

• H04B15/005

  Reducing noise, e.g. humm, from the supply · CPC title