Abstract: Voltage regulators for battery operated systems are provided. In certain implementations, a voltage regulator is operable in a regulating mode and a bypass mode. In the regulating mode, an input voltage greater than a selected value can be regulated so as to yield a desired output voltage. In the bypass mode, an input voltage at or less than the selected value can be regulated so as to yield an output voltage that substantially tracks the input voltage. Such a capability of switching between two modes can provide advantageous features such as reducing the likelihood of damage in a powered circuit due to high input voltage, and extending the operating duration of a power source such as a rechargeable battery. Also disclosed are examples of how the foregoing features can be implemented in different products and methods of operation and fabrication.

Abstract: Apparatus and methods for reducing inductor ringing of a voltage converter are provided. In certain configurations, a voltage converter includes an inductor connected between a first node and a second node, a plurality of switches, and a bypass circuit having an activated state and a deactivated state. The switches includes a first switch connected between a battery voltage and the first node, a second switch connected between the first node and a ground voltage, a third switch connected between the second node and the ground voltage, and a fourth switch connected between the second node and the output. The bypass circuit includes a first pair of transistors connected between the first node and the second node and configured to turn on to bypass the inductor in the activated state and to turn off in the deactivated state.

Abstract: Voltage regulators for battery operated systems are provided. In certain implementations, a voltage regulator is operable in a regulating mode and a bypass mode. In the regulating mode, an input voltage greater than a selected value can be regulated so as to yield a desired output voltage. In the bypass mode, an input voltage at or less than the selected value can be regulated so as to yield an output voltage that substantially tracks the input voltage. Such a capability of switching between two modes can provide advantageous features such as reducing the likelihood of damage in a powered circuit due to high input voltage, and extending the operating duration of a power source such as a rechargeable battery. Also disclosed are examples of how the foregoing features can be implemented in different products and methods of operation and fabrication.

Abstract: Methods for fabricating an integrated circuit with a voltage regulator are provided. In some implementations, a method includes forming a primary regulator on a semiconductor substrate, including fabricating a switch, fabricating an amplifier for controlling the switch, and fabricating a voltage generator for biasing the amplifier to operate the primary regulator in a bypass mode or in a regulating mode. The method further includes forming an input terminal and an output terminal of the primary regulator on the semiconductor substrate, forming a secondary regulator on the substrate, forming an input terminal and an output terminal of the secondary regulator on the semiconductor substrate, and forming an electrical connection between the output terminal of the primary regulator and the input terminal of the secondary regulator.

Abstract: Apparatus and methods for reducing inductor ringing of a voltage converter are provided. In certain configurations, a voltage converter includes an inductor connected between a first node and a second node, a plurality of switches, and a bypass circuit having an activated state and a deactivated state. The switches includes a first switch connected between a battery voltage and the first node, a second switch connected between the first node and a ground voltage, a third switch connected between the second node and the ground voltage, and a fourth switch connected between the second node and the output. The bypass circuit includes a first pair of transistors connected between the first node and the second node and configured to turn on to bypass the inductor in the activated state and to turn off in the deactivated state.

Abstract: Envelope tracking for radio-frequency applications. In some embodiments, a low frequency loss correction circuit can include a signal error detection circuit configured to produce an error signal in response to detecting one or more frequency components of a tracking signal below a cutoff frequency that are substantially attenuated through a capacitive path. The low frequency loss correction circuit can further include a drive circuit configured to convert the error signal into a low frequency correction signal, and provide the low frequency correction signal to a voltage supply line, the low frequency correction signal including at least some of the one or more frequency components of the tracking signal below a cutoff frequency that are substantially attenuated through the capacitive path.

Abstract: Apparatus and methods for voltage regulation are provided. In some implementations, a voltage regulator circuit includes a field-effect transistor including a source that receives a battery voltage from an input node and a drain coupled to an output node, an amplifier including an output coupled to a gate of the field-effect transistor, and a voltage generator that receives the battery voltage from the input node and provides a reference voltage and one or more bias voltages to the amplifier. The voltage generator controls the amplifier to operate the voltage regulator circuit in a regulation mode or in a bypass mode based on a voltage level of the battery voltage. The amplifier and the field-effect transistor regulate the battery voltage in the regulation mode to provide a regulated voltage at the output node, and the amplifier turns on the field-effect transistor in the bypass mode to provide a bypass voltage substantially equal to the battery voltage at the output node.

Abstract: Voltage regulator circuits for wireless devices are provided. In some implementations, a transceiver module includes a transceiver circuit that generates a radio frequency (RF) signal, a power amplifier circuit that receives the RF signal and generates an amplified RF signal, and a voltage regulator circuit that receives an input voltage and provides a desired voltage to the power amplifier circuit. The voltage regulator circuit is operable in a regulation mode in which the desired voltage includes a regulated voltage and in a bypass mode in which the desired voltage includes a bypass voltage. The voltage regulator circuit includes a field-effect transistor (FET) electrically connected between the input voltage and the desired voltage, an amplifier that controls the FET, and a voltage generator that receives the input voltage and biases the amplifier.

Abstract: Apparatus and methods for reducing inductor ringing of a voltage converter are provided. In certain configurations, a voltage converter includes an inductor connected between a first node and a second node, a plurality of switches, and a bypass circuit having an activated state and a deactivated state. The switches includes a first switch connected between a battery voltage and the first node, a second switch connected between the first node and a ground voltage, a third switch connected between the second node and the ground voltage, and a fourth switch connected between the second node and the output. The bypass circuit includes a first pair of transistors connected between the first node and the second node and configured to turn on to bypass the inductor in the activated state and to turn off in the deactivated state.

Abstract: A low frequency loss correction circuit that improves the efficiency of a power amplifier at near-DC low frequencies The low frequency loss correction circuit can include a signal error detection circuit configured to produce an error signal in response to detecting one or more frequency components of a tracking signal below a cutoff frequency that are substantially attenuated through a capacitive path. The low frequency loss correction circuit can include a drive circuit configured to convert the error signal into a low frequency correction signal, and provide the low frequency correction signal to a voltage supply line, the low frequency correction signal including at least some of the one or more frequency components of the tracking signal below a cutoff frequency that are substantially attenuated through the capacitive path.

Abstract: Apparatus and methods for reducing inductor ringing of a voltage converter are provided. In certain configurations, a voltage converter includes an inductor connected between a first node and a second node, a plurality of switches, and a bypass circuit having an activated state and a deactivated state. The switches includes a first switch connected between a battery voltage and the first node, a second switch connected between the first node and a ground voltage, a third switch connected between the second node and the ground voltage, and a fourth switch connected between the second node and the output. The bypass circuit includes a first pair of transistors connected between the first node and the second node and configured to turn on to bypass the inductor in the activated state and to turn off in the deactivated state.

Abstract: Apparatus and methods for negative voltage generation with reduced clock feed-through are provided. In certain configurations, a method of negative voltage generation in a wireless device is provided. The method includes generating a regulated voltage from a battery voltage using a voltage regulator, powering a first charge pump and a second charge pump using the regulated voltage, generating a first negative voltage based on timing of a first clock phase using the first charge pump, generating a second negative voltage based on the first negative voltage and on timing of a second clock phase using the second charge pump, and generating the first clock phase and the second clock phase with different phases using a poly-phase oscillator such that the first charge pump and the second charge pump draw from the regulated voltage at different points in time.

Abstract: Apparatus and methods for bypassing an inductor of a voltage converter are provided. In one embodiment, a voltage converter includes an inductor and a bypass circuit that selectively bypasses the inductor based on a state of a bypass control signal. The inductor includes including a first end electrically connected to a first node and a second end electrically connected to a second node. The bypass circuit includes a first p-type field effect transistor and a second p-type field effect transistor electrically connected in series between the first node and the second node. The first p-type field effect transistor includes a body electrically connected to a first voltage, and the second p-type field effect transistor includes a body electrically connected to a second voltage greater than the first voltage.

Abstract: Methods for fabricating an integrated circuit with a voltage regulator are provided. In some implementations, a method includes forming a primary regulator on a semiconductor substrate, including fabricating a switch, fabricating an amplifier for controlling the switch, and fabricating a voltage generator for biasing the amplifier to operate the primary regulator in a bypass mode or in a regulating mode. The method further includes forming an input terminal and an output terminal of the primary regulator on the semiconductor substrate, forming a secondary regulator on the substrate, forming an input terminal and an output terminal of the secondary regulator on the semiconductor substrate, and forming an electrical connection between the output terminal of the primary regulator and the input terminal of the secondary regulator.

Abstract: Apparatus and methods for voltage regulation are provided. In some implementations, a voltage regulator circuit includes a field-effect transistor including a source that receives a battery voltage from an input node and a drain coupled to an output node, an amplifier including an output coupled to a gate of the field-effect transistor, and a voltage generator that receives the battery voltage from the input node and provides a reference voltage and one or more bias voltages to the amplifier. The voltage generator controls the amplifier to operate the voltage regulator circuit in a regulation mode or in a bypass mode based on a voltage level of the battery voltage. The amplifier and the field-effect transistor regulate the battery voltage in the regulation mode to provide a regulated voltage at the output node, and the amplifier turns on the field-effect transistor in the bypass mode to provide a bypass voltage substantially equal to the battery voltage at the output node.

Abstract: Voltage regulator circuits for wireless devices are provided. In some implementations, a transceiver module includes a transceiver circuit that generates a radio frequency (RF) signal, a power amplifier circuit that receives the RF signal and generates an amplified RF signal, and a voltage regulator circuit that receives an input voltage and provides a desired voltage to the power amplifier circuit. The voltage regulator circuit is operable in a regulation mode in which the desired voltage includes a regulated voltage and in a bypass mode in which the desired voltage includes a bypass voltage. The voltage regulator circuit includes a field-effect transistor (FET) electrically connected between the input voltage and the desired voltage, an amplifier that controls the FET, and a voltage generator that receives the input voltage and biases the amplifier.

Abstract: Circuits and methodologies related to high-voltage tolerant regulators are disclosed. In some implementations, a voltage regulator can be configured to be capable of being in a regulating state and a bypass state. In the regulating state, an input voltage greater than a selected value can be regulated so as to yield a desired output voltage such as a substantially constant voltage. In the bypass state, an input voltage at or less than the selected value can be regulated so as to yield an output voltage that substantially tracks the input voltage. Such a capability of switching between two modes can provide advantageous features such as reducing the likelihood of damage in a powered circuit due to high input voltage, and extending the operating duration of a power source such as a rechargeable battery. Also disclosed are examples of how the foregoing features can be implemented in different products and methods of operation and fabrication.

Abstract: Apparatus and methods for negative voltage generation with reduced clock feed-through are provided. In certain configurations, a method of negative voltage generation in a wireless device is provided. The method includes generating a regulated voltage from a battery voltage using a voltage regulator, powering a first charge pump and a second charge pump using the regulated voltage, generating a first negative voltage based on timing of a first clock phase using the first charge pump, generating a second negative voltage based on the first negative voltage and on timing of a second clock phase using the second charge pump, and generating the first clock phase and the second clock phase with different phases using a poly-phase oscillator such that the first charge pump and the second charge pump draw from the regulated voltage at different points in time.

Abstract: Implementations of radio frequency switch controllers within the scope of the appended claims are configured to reduce the impact of the clock signal induced spurs. In particular, implementations of switch controllers described herein include a poly-phase clocking scheme, as opposed to a single phase to clock the charge pump stages of an negative voltage generator. In some implementations poly-phase clocking schemes reduce the clock signal induced spurs and may preclude the need for additional on-chip or off-chip decoupling capacitors that add to the cost and physical size of a complete front end module solution.

Abstract: Implementations of radio frequency switch controllers within the scope of the appended claims are configured to reduce the impact of the clock signal induced spurs. In particular, implementations of switch controllers described herein include a poly-phase clocking scheme, as opposed to a single phase to clock the charge pump stages of an negative voltage generator. In some implementations poly-phase clocking schemes reduce the clock signal induced spurs and may preclude the need for additional on-chip or off-chip decoupling capacitors that add to the cost and physical size of a complete front end module solution.