Switching regulator circuits and methods with reconfigurable inductance

Patent metadata

Field	Value
Publication number	US-2016294284-A1
Application number	US-201514675354-A
Country	US
Kind code	A1
Filing date	Mar 31, 2015
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

The present disclosure includes switching regulator circuits and methods having reconfigurable inductance. In one embodiment, a circuit comprises a switching regulator, the switching regulator receiving a switching signal having a switching frequency, a monitor circuit to monitor the switching frequency, and a reconfigurable inductance at an output of the switching regulator, wherein the monitor circuit changes the reconfigurable inductance between a plurality of inductance values based on the switching frequency. In envelope tracking applications, an envelope tracking signal frequency and switching frequency are monitored to adjust a switching stage inductance.

First claim

What is claimed is:

1 . A circuit comprising:
a switching regulator, the switching regulator receiving a switching signal having a switching frequency; a monitor circuit to monitor the switching frequency; and a reconfigurable inductance at an output of the switching regulator, wherein the monitor circuit changes the reconfigurable inductance between a plurality of inductance values based on the switching frequency.

2 . The circuit of claim 1 wherein the reconfigurable inductance comprises a plurality of inductors and a plurality of switches.

3 . The circuit of claim 1 wherein when the switching frequency is a first frequency, the reconfigurable inductance has a first inductance value, and wherein when the switching frequency is a second frequency greater than the first frequency, the reconfigurable inductance has a second inductance value less than the first inductance value.

4 . The circuit of claim 1 wherein, in a first configuration, the reconfigurable inductance comprises a plurality of inductors in parallel, and wherein, in a second configuration, the reconfigurable inductance comprises a plurality of inductors in series.

5 . The circuit of claim 4 wherein, in the first configuration, the reconfigurable inductance comprises two inductors in parallel, and wherein, in a second configuration, the reconfigurable inductance comprises said two inductors in series.

6 . The circuit of claim 1 further comprising:
an amplifier to receive an envelope tracking signal, wherein an output of the amplifier is coupled to an output of the switching regulator to provide a power supply voltage; and
a switching generator circuit to produce the switching signal based on the envelope tracking signal,
wherein the monitor circuit compares a frequency of the envelope tracking signal to the switching frequency of the switching signal, and in accordance therewith, changes the reconfigurable inductance.

7 . The circuit of claim 6 wherein the estimator circuit alternately changes the reconfigurable inductance between a plurality of discrete inductance values when the frequency of the envelope tracking signal is less than the switching frequency of the switching signal to produce an average inductance, and wherein the average inductance is decreased as the frequency of the envelope tracking signal increases.

8 . The circuit of claim 6 wherein the estimator circuit comprises:
a first detector circuit to produce a first clock signal based on a time difference between peaks in the envelope tracking signal and valleys in the envelope tracking signal;
a second detector circuit to produce a second clock signal based on edges of the switching signal; and
a frequency comparison circuit to compare a frequency of the first clock signal to the frequency of the second clock signal, and in accordance therewith, produce a logic signal to change the reconfigurable inductance.

9 . A method comprising:
monitoring a switching frequency of a switching regulator; and reconfiguring an inductance at an output of the switching regulator between a plurality of inductance values based on the switching frequency.

10 . The method of claim 9 wherein the inductance is reduced as the switching frequency increases.

11 . The method of claim 9 wherein reconfiguring the inductance comprises alternately changing the inductance between a plurality of discrete inductance values to produce an average inductance.

12 . The method of claim 9 wherein the inductance comprises a plurality of inductors coupled together by a plurality of switches, and wherein reconfiguring the inductance comprises turning on one or more switches and turning off one or more other switches.

13 . The method of claim 9 wherein, in a first configuration, the inductance comprises a plurality of inductors configured in parallel, and wherein, in a second configuration, the inductance comprises a plurality of inductors configured in series.

14 . The method of claim 13 wherein, in the first configuration, the reconfigurable inductance comprises two inductors in parallel, and wherein, in a second configuration, the reconfigurable inductance comprises said two inductors in series.

15 . The method of claim 9 further comprising:
receiving an envelope tracking signal at an input of an amplifier, wherein an output of the amplifier is coupled to an output of the switching regulator to provide a power supply voltage;
generating the switching signal based on the envelope tracking signal; and
comparing a frequency of the envelope tracking signal to the switching frequency of the switching signal, and in accordance therewith, changing the inductance.

16 . The method of claim 15 further comprising:
detecting a time difference between peaks in the envelope tracking signal and valleys in the envelope tracking signal to produce a first clock signal;
detecting edges of the switching signal to produce a second clock signal; and
comparing a frequency of the first clock signal to a frequency of the second clock signal, and in accordance therewith, producing a signal to reconfigure the inductance.

17 . A circuit comprising:
a switching regulator, the switching regulator receiving a switching signal having a switching frequency; reconfigurable inductance means at an output of the switching regulator; and means for monitoring a switching frequency and changing the reconfigurable inductance means between a plurality of inductance values based on the switching frequency.

18 . The circuit of claim 17 wherein the inductance is reduced as the switching frequency increases.

19 . The circuit of claim 17 further comprising:
an amplifier to receive an envelope tracking signal, wherein an output of the amplifier is coupled to an output of the switching regulator to provide a power supply voltage; and
means for generating the switching signal based on the envelope tracking signal; and
means for comparing a frequency of the envelope tracking signal to the switching frequency of the switching signal, and in accordance therewith, changing the reconfigurable inductance.

20 . The circuit of claim 17 wherein, in a first configuration, the reconfigurable inductance means comprises a plurality of inductors in parallel, and wherein, in a second configuration, the reconfigurable inductance means comprises a plurality of inductors in series.

Assignees

• Qualcomm Inc

Inventors

• Lerdworatawee Jongrit
• Shi Chunlei

Classifications

• H03F1/0227

  using supply converters · CPC title

• H02M3/155 Primary

  using semiconductor devices only · CPC title

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title

• H03F3/2173

  of the bridge type · CPC title

• H03F2200/432

  Two or more amplifiers of different type are coupled in parallel at the input or output, e.g. a class D and a linear amplifier, a class B and a class A amplifier · CPC title