RF switching converter with ripple correction

• US 9,484,797 B2
• Filed: 10/26/2012
• Issued: 11/01/2016
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Khlat, Nadim
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Torres-Rivera, Alex
• Application Number:
  US13/661,227
• Publication Number:
  US 20130106378A1
• Time in Patent Office: 1,467 Days
• Field of Search: 323/268, 323/272, 323/274, 323/275, 323/279, 323/282, 323/283, 323/284, 323/285, 323/286, 323/288, 323/290
• US Class Current: 1/1
• CPC Class Codes: H02M 1/15 using active elements
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

This disclosure relates generally to radio frequency (RF) switching converters and RF amplification devices that use RF switching converters. In one embodiment, an RF switching converter includes a switching circuit operable to receive a power source voltage, a switching controller configured to switch the switching circuit so that the switching circuit generates a pulsed output voltage from the power source voltage, and an RF filter configured to convert the pulsed output voltage into a supply voltage, wherein the RF filter includes a decoupling capacitor configured to receive the supply voltage. The switching controller is configured to generate a ripple correction current that is injected into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current. The decoupling capacitor outputs the ripple correction current such that the ripple correction current reduces a ripple variation in a supply current level of a supply current resulting from the supply voltage.

Claims

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 configured to convert the pulsed output voltage into a supply voltage, wherein the RF filter has a decoupling capacitor configured to receive the supply voltage;

a switching controller configured to;

switch the switching circuit so that the switching circuit generates the pulsed output voltage;

generate a ripple correction current;

inject the ripple correction current into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current to provide a filtered ripple correction current, wherein the decoupling capacitor outputs the filtered ripple correction current such that the filtered ripple correction current reduces a ripple variation in a supply current level of a supply current resulting from the supply voltage;

receive a Resource Block (RB) parameter that indicates an integer number of RBs;

generate a control signal in an activation state when the RB parameter indicates that the integer number is less than an RB threshold value, and in a deactivation state when the RB parameter indicates that the integer number is greater than or equal to the RB threshold value; and

transmit the control signal to a switch, wherein the switch is configured to be closed in response to the control signal being in the activation state, and the switch is configured to be opened in response to the control signal being in the deactivation state;

wherein the decoupling capacitor has a first capacitance and the switching controller further comprises a shunt-coupled circuit, the shunt-coupled circuit comprising;

a second decoupling capacitor having a second capacitance that is smaller than the first capacitance of the decoupling capacitor; and

the switch coupled in series with the second decoupling capacitor, wherein the switch is configured to be opened and closed; and

wherein the shunt-coupled circuit is coupled in shunt with respect to the decoupling capacitor such that the second decoupling capacitor further filters the filtered ripple correction current when the switch is closed, and does not further filter the filtered ripple correction current when the switch is open.

2. The RF switching converter of claim 1 wherein the switching controller comprises a bang-bang controller (BBC) configured to switch the switching circuit so that the switching circuit generates the pulsed output voltage.

3. The RF switching converter of claim 1 wherein the switching controller is further configured to:

generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current; and

adjust the sense signal level of the current sense signal in response to a change in a supply voltage level of the supply voltage at the decoupling capacitor, such that the sense signal level varies in accordance with the ripple variation in the supply current level of the supply current.

4. The RF switching converter of claim 1 wherein the switching controller comprises a current sense detector configured to generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current and adjust the sense signal level of the current sense signal in response to a change in a supply voltage level of the supply voltage at the decoupling capacitor.

5. The RF switching converter of claim 4 wherein the switching controller further comprises a ripple current correction circuit configured to generate the ripple correction current based on the supply current level of the supply current, the ripple current correction circuit being coupled to inject the ripple correction current into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current to provide the filtered ripple correction current.

6. The RF switching converter of claim 1 wherein the switching controller comprises a ripple current correction circuit configured to generate the ripple correction current, the ripple current correction circuit being coupled to inject the ripple correction current into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current to provide the filtered ripple correction current.

7. The RF switching converter of claim 1 wherein the RB parameter indicates the integer number of RBs for a time slot.

8. The RF switching converter of claim 7 wherein the switching controller comprises a current sense detector, the current sense detector being configured to generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current resulting from the supply voltage and adjust the sense signal level of the current sense signal in response to a change in a supply voltage level of the supply voltage at the decoupling capacitor, the current sense detector having a comparator and a feedback circuit wherein:

the feedback circuit is configured to generate a feedback voltage having a feedback voltage level indicative of the supply voltage level of the supply voltage;

the comparator comprises a first input terminal configured to receive an input voltage, a second input terminal configured to receive the feedback voltage from the feedback circuit, and an output terminal configured to generate an output voltage based on the input voltage and the feedback voltage; and

the decoupling capacitor is further coupled to receive the output voltage.

9. The RF switching converter of claim 8 wherein the feedback circuit includes the shunt-coupled circuit.

10. The RF switching converter of claim 1 wherein the switching converter is further configured to:

generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current resulting from the supply voltage; and

adjust the sense signal level of the current sense signal in response to a change in a supply voltage level of the supply voltage at the decoupling capacitor, such that the sense signal level varies in accordance with the ripple variation in the supply current level of the supply current;

wherein the switching controller is configured to generate the ripple correction current based on the sense signal level of the current sense signal so that the ripple correction current is an estimated mirror of the supply current.

11. 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 configured to convert the pulsed output voltage into a supply voltage;

a decoupling capacitor coupled to receive the supply voltage;

a switching controller configured to switch the switching circuit so that the switching circuit generates the pulsed output voltage by being configured to;

switch the switching circuit so that the switching circuit generates the pulsed output voltage;

generate a ripple correction current;

inject the ripple correction current into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current to provide a filtered ripple correction current, wherein the decoupling capacitor outputs the filtered ripple correction current such that the filtered ripple correction current reduces a ripple variation in a supply current level of a supply current resulting from the supply voltage;

receive a Resource Block (RB) parameter that indicates an integer number of RBs;

generate a control signal in an activation state when the RB parameter indicates that the integer number is less than an RB threshold value, and in a deactivation state when the RB parameter indicates that the integer number is greater than or equal to the RB threshold value; and

transmit the control signal to a switch, wherein the switch is configured to be closed in response to the control signal being in the activation state, and the switch is configured to be opened in response to the control signal being in the deactivation state;

wherein the decoupling capacitor has a first capacitance and the switching controller further comprises a shunt-coupled circuit, the shunt-coupled circuit comprising;

a second decoupling capacitor having a second capacitance that is smaller than the first capacitance of the decoupling capacitor; and

the switch coupled in series with the second decoupling capacitor, wherein the switch is configured to be opened and closed

wherein the shunt-coupled circuit is coupled in shunt with respect to the decoupling capacitor such that the second decoupling capacitor further filters the filtered ripple correction current when the switch is closed, and does not further filter the filtered ripple correction current when the switch is open; and

a ripple current correction circuit configured to generate the ripple correction current, the ripple current correction circuit being coupled so as to inject the ripple correction current into the decoupling capacitor such that the decoupling capacitor filters the ripple correction current to provide the filtered ripple correction current, wherein the decoupling capacitor outputs the filtered ripple correction current such that the filtered ripple correction current reduces a ripple variation in a supply current level of a supply current resulting from the supply voltage.

12. The RF switching converter of claim 11 further comprising a current sense detector configured to:

generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current; and

adjust the sense signal level of the current sense signal in response to a change in a supply voltage level of the supply voltage at the decoupling capacitor, such that the sense signal level varies in accordance with the ripple variation in the supply current level of the supply current; and

wherein the ripple current correction circuit is configured to generate the ripple correction current based on the sense signal level of the current sense signal.

13. The RF switching converter of claim 12 wherein:

the switching controller includes the current sense detector and the ripple current correction circuit; and

the RF filter includes the decoupling capacitor.

14. The RF switching converter of claim 11 wherein the RB parameter indicates the integer number of RBs for a time slot.

15. The RF switching converter of claim 11 comprising a current sense detector having a comparator and a feedback circuit wherein:

the feedback circuit is configured to generate a feedback voltage having a feedback voltage level indicative of a supply voltage level of the supply voltage;

the comparator comprises a first input terminal configured to receive an input voltage, a second input terminal configured to receive the feedback voltage from the feedback circuit, and an output terminal, wherein the comparator is configured to generate an output voltage from the output terminal based on the input voltage and the feedback voltage; and

the decoupling capacitor is further coupled to receive the output voltage such that a capacitor voltage across the decoupling capacitor has a voltage level directly related to a voltage difference between the supply voltage level of the supply voltage and an output voltage level of the output voltage.

16. The RF switching converter of claim 15 wherein the feedback circuit includes the shunt-coupled circuit.

17. The RF switching converter of claim 15 further comprising the current sense detector configured to generate a current sense signal having a sense signal level set so as to indicate the supply current level of the supply current, and to adjust the sense signal level of the current sense signal in response to a change in the supply voltage level of the supply voltage at the decoupling capacitor such that the sense signal level varies in accordance with the ripple variation in the supply current level of the supply current wherein the switching controller is configured to generate the ripple correction current based on the sense signal level of the current sense signal so that the ripple correction current is an estimated mirror of the supply current.