Apparatus and method for voltage distribution

Abstract

Apparatus and methods for regulated voltage distribution are disclosed. Distribution elements can pass a regulated voltage provided by a single voltage regulator to thereby distribute the regulated voltage. A distribution element of the distribution elements can be included in a feedback path that provides a feedback signal to an input of the voltage regulator. The voltage regulator can be a low dropout voltage regulator, for example. The regulated voltage can be used in a variety of applications, for example, as a bias voltage for a power amplifier.

1 . (canceled) 
     
     
         2 . An electronic system with voltage distribution, the electronic system comprising:
 a low dropout voltage regulator including an error amplifier and a pass transistor electrically connected to an output of the error amplifier, the pass transistor configured to provide a regulated voltage; and   a voltage distribution circuit configured to receive the regulated voltage from the pass transistor, the voltage distribution circuit including a first distribution element and a second distribution element, the first distribution element configured to pass the regulated voltage in a first mode, the first distribution element being included in a feedback loop to an input of the low voltage dropout regulator in the first mode, and the second distribution element configured to pass the regulated voltage in a second mode.   
     
     
         3 . The electronic system of  claim 2  further comprising a first power amplifier and a second power amplifier, the first power amplifier electrically connected to the first distribution element, and the second power amplifier electrically connected to the second distribution element. 
     
     
         4 . The electronic system of  claim 2  further comprising a variable voltage control element configured to receive the regulated voltage from the first distribution element and to generate a variable regulated voltage by varying the regulated voltage responsive to a control signal. 
     
     
         5 . The electronic system of  claim 2  wherein the feedback loop includes a resistor of a voltage divider. 
     
     
         6 . The electronic system of  claim 2  wherein the first mode is a first power mode and the second mode is a second power mode. 
     
     
         7 . The electronic system of  claim 2  wherein the first distribution element includes a field effect transistor. 
     
     
         8 . The electronic system of  claim 2  wherein the first distribution element includes a first transistor and the second distribution element includes a second transistor, and the first transistor and the second transistor are configured to receive different control signals. 
     
     
         9 . The electronic system of  claim 2  further comprising a switch electrically coupled between the distribution element and the input of the low dropout regulator. 
     
     
         10 . A method of regulated voltage distribution, the method comprising:
 generating a regulated voltage with a low dropout regulator, the low dropout regulator including an error amplifier and a pass transistor electrically connected to an output of the error amplifier;   passing the regulated voltage with a first distribution element in a first mode, the first distribution element configured to receive the regulated voltage from the pass transistor;   providing a feedback signal to an input of the low dropout regulator with a feedback loop in the first mode, the feedback loop including the first distribution element; and   passing the regulated voltage with a second distribution element in a second mode, the second distribution element configured to receive the regulated voltage from the pass transistor.   
     
     
         11 . The method of  claim 10  further comprising varying the regulated voltage with a variable voltage control element to generate a variable regulated voltage in the first mode, the variable voltage control element electrically connected to the first distribution element. 
     
     
         12 . The method of  claim 11  further comprising biasing a power amplifier with the variable regulated voltage. 
     
     
         13 . The method of  claim 11  further comprising varying the regulated voltage with a second variable voltage control element to generate a second variable regulated voltage in the second mode, the second variable voltage control element electrically connected to the second distribution element. 
     
     
         14 . The method of  claim 10  wherein the first distribution element is electrically connected to a first power amplifier, and the second distribution element is electrically connected to a second power amplifier. 
     
     
         15 . The method of  claim 10  wherein the feedback loop includes a switch electrically coupled between the first distribution element and the input of the low dropout regulator. 
     
     
         16 . The method of  claim 15  wherein the feedback loop includes a resistor of a voltage divider. 
     
     
         17 . An electronic apparatus with variable voltage distribution, the electronic apparatus comprising:
 means for generating a regulated voltage based on a power supply voltage and a comparison of a reference voltage with a feedback signal generated based on the regulated voltage, the reference voltage being different than the power supply voltage;   means for generating variable regulated voltages from the regulated voltage, the variable regulated voltages being at different voltage levels when one or more loads configured to receive at least one of the variable regulated voltages operate in different power modes; and   means for selectively distributing the regulated voltage to the means for generating the variable regulated voltages, the means for selectively distributing configured to electrically couple the regulated voltage to only a portion of the one or more loads via the means for generating the variable regulated voltages in a selected one of the different power modes.   
     
     
         18 . The electronic apparatus of  claim 17  wherein the means for selectively distributing include a distribution element included in a feedback loop in which the feedback signal is generated in at least one of the different power modes. 
     
     
         19 . The electronic apparatus of  claim 17  wherein the means for selectively distributing include a first distribution element and a second distribution element, the first distribution element configured to close a feedback loop in a first mode of the different power modes, the second distribution element configured to close the feedback loop in a second mode of the different power modes, the feedback loop being configured to provide the feedback signal. 
     
     
         20 . The electronic apparatus of  claim 17  wherein the means for selectively distributing are configured to selectively provide the regulated voltage to different variable voltage control elements of the means for generating variable regulated voltages in the different power modes. 
     
     
         21 . The electronic apparatus of  claim 17  wherein the one or more loads include a plurality of power amplifiers.