Pseudo-envelope following power management system

• US 8,493,141 B2
• Filed: 04/19/2011
• Issued: 07/23/2013
• Est. Priority Date: 04/19/2010
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Khlat, Nadim, Kay, Michael R.
• Primary Examiner(s): NGUYEN, PATRICIA T
• Application Number:
  US13/089,917
• Publication Number:
  US 20120293253A1
• Time in Patent Office: 826 Days
• Field of Search: 330/127, 330/297, 327/536
• US Class Current: 330/127
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H03F 1/0238 using supply converters
• CPC Class Codes: H03F 1/0244 Stepped control
• CPC Class Codes: H03F 1/025 by using a signal derived from the input signal
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit
• CPC Class Codes: H03F 2200/375 Circuitry to compensate the offset being present in an amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/555 A voltage generating circuit being realised for biasing different circuit elements
• CPC Class Codes: H03F 3/189 High-frequency amplifiers, e.g. radio frequency amplifiers
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/21 with semiconductor devices only H03F3/245 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03G 3/004 Control by varying the supply voltage

Abstract

Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Claims

1. A power management system for an RF power amplifier comprising:

a parallel amplifier including a supply input configured to receive a direct current input voltage and an amplifier in communication with a power amplifier supply voltage; and

a multi-level charge pump buck converter including a supply input configured to receive the direct current input voltage and a switching voltage output in communication with the power amplifier supply voltage, wherein the multi-level charge pump buck converter is configured to shunt the switching voltage output to ground in a first operational state, provide the direct current input voltage to the switching voltage output in a second operational state, provide 1.5 times the direct current input voltage to the switching voltage output in a third operational state, and provide 2 times the direct current input voltage to the switching voltage output in a fourth operational state.

2. The power management system of claim 1 wherein the multi-level charge pump buck converter is further configured to provide 0.5 times the direct current input voltage to the switching voltage output in a fifth operational state.

3. The power management system of claim 1 further comprising a power inductor coupled between the switching voltage output and the power amplifier supply voltage;

and

a bypass capacitor coupled between the power amplifier supply voltage and ground.