US 8,525,595 B2Granted

Vramp limiting using resistors

AssigneeRF Micro Devices, Inc.

InventorsJean-Christophe Berchtold, Erik Pedersen

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Abstract

Power amplification devices are described, which are configured to amplify a radio frequency (RF) transmission signal. The power amplification device includes a voltage regulation circuit and a power amplification circuit. The voltage regulation circuit includes a voltage regulator that is operable to generate a regulated voltage from the supply voltage and a feedback circuit that sets a voltage adjustment gain of the voltage regulation circuit. To help prevent the voltage regulation circuit from saturating, the feedback circuit reduces the voltage adjustment gain in response to a voltage difference reaching a threshold voltage level. The voltage difference is between a voltage regulator control signal level of a voltage regulator control signal and the regulated voltage level of the regulated voltage. This configuration can be utilized to reduce a drop-out voltage level of the voltage regulator and get better performance despite supply voltage degradation and variations in operational conditions, such as temperature.

Claims20

Dependent claims

A power amplification device configured to amplify a radio frequency (RF) transmission signal using a supply voltage, comprising:

a voltage regulation circuit having a voltage adjustment gain, wherein the voltage regulation circuit comprises:
a differential amplifier configured to receive a voltage control signal and a feedback signal;
a voltage regulator configured to receive a voltage regulator control signal and generate a regulated voltage from the supply voltage, wherein a regulated voltage level of the regulated voltage is set in accordance with a voltage regulator control signal level of the voltage regulator control signal;
the voltage regulator being operably associated with the differential amplifier so that the differential amplifier is operable to generate the voltage regulator control signal wherein the voltage regulator control signal level adjust the regulated voltage level in accordance with the voltage adjustment gain and a first voltage difference between a voltage control signal level of the voltage control signal and a feedback signal level of the feedback signal;
a feedback circuit coupled so as to generate the feedback signal from the regulated voltage and provide the feedback signal to the differential amplifier and so as to set the voltage adjustment gain of the voltage regulation circuit, wherein the feedback circuit is responsive to a second voltage difference between the voltage regulator control signal level and the regulated voltage level such that the voltage adjustment gain is reduced once the second voltage difference reaches a threshold voltage level;
and
a power amplification circuit operable to amplify the RF transmission signal in accordance with an amplification gain wherein the power amplification circuit is operably associated with the voltage regulation circuit such that the amplification gain of the power amplification circuit is adjusted by the regulated voltage level of the regulated voltage.

4 more elements

A method of controlling an amplification gain of a power amplification circuit configured to amplify a radio frequency (RF) transmission signal wherein the amplification gain is adjusted by a regulated voltage level of a regulated voltage, the method comprising:

receiving a voltage control signal such that a voltage control signal level of the voltage control signal is increased from a minimum voltage control signal level to a maximum voltage control signal level during a ramp-up period;
during the ramp-up period, generating the regulated voltage having the regulated voltage level with a voltage regulator;
during the ramp-up period, generating a feedback signal having a feedback signal level from the regulated voltage;
during the ramp-up period, providing a voltage regulator control signal to the voltage regulator wherein the voltage regulator control signal has a voltage regulator control signal level that adjust the regulated voltage level of the regulated voltage in accordance a voltage adjustment gain and a first voltage difference between the voltage control signal level and the feedback signal level;
during the ramp-up period, providing the regulated voltage to the power amplification circuit;
and
during the ramp-up period and once a second voltage difference between the voltage regulator control signal level and the regulated voltage level reaches a threshold voltage level, reducing the voltage adjustment gain.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/360,094Filed 27 Jan 2012 · us provisional application
Priority: 27 Jan 2011
Published: US 2013/0021099 A124 Jan 2013
Granted: 3 Sep 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

H03G 3/004
Gain control in amplifiers or frequency changers: control by varying the supply voltage
H03F 1/0238
By using a signal derived from the output signal, e.g. bootstrapping the voltage supply: using supply converters
H03F 3/195
With semiconductor devices only: in integrated circuits
H03F 3/245
Of transmitter output stages: with semiconductor devices only