Abstract: A power supply switch circuit includes a first transistor that switches supplying of a first power supply voltage to a power supply terminal of a power amplifier, a switch controller that controls the first transistor and to which a second power supply voltage is applied, and a voltage selector that selects a higher voltage among the first power supply voltage and the second power supply voltage. The selected higher voltage is applied to a body terminal of the first transistor or a gate terminal of the first transistor.

Abstract: A charge pump system includes a charge pump circuit including an input terminal configured to receive an input voltage and an output terminal configured to output an output voltage, and configured to convert the input voltage to the output voltage; a first resistor including one terminal connected to a reference voltage; a second resistor connected between another terminal of the first resistor and the charge pump circuit output terminal; a third resistor including one terminal connected to the reference voltage; a fourth resistor connected between another terminal of the third resistor and a ground; an amplifier including a first input terminal connected to the other terminal of the first resistor, a second input terminal connected to the other terminal of the third resistor; and a first transistor including a control terminal connected to an amplifier output terminal, and a first terminal connected to the charge pump circuit input terminal.

Abstract: An envelope tracking bias circuit that generates a bias current to a power amplifier that amplifies a radio frequency (RF) signal is provided. The envelope tracking bias circuit includes an envelope detector configured to detect an envelope signal of the RF signal; an envelope bandwidth detector configured to detect a frequency band of the envelope signal; and a bias output circuit that generates a bias current based on an average magnitude of the envelope signal when the frequency band of the envelope signal is greater than or equal to a predetermined frequency, and generates a bias current in response to the envelope signal when the frequency band of the envelope signal is lower than the predetermined frequency.

Abstract: A power amplifier is provided. The power amplifier includes a power transistor configured to amplify and output an input radio frequency (RF) signal; a first transistor including a first terminal that provides a bias current to the power transistor; and a second transistor including a first terminal connected to a control terminal of the first transistor and a control terminal connected to the first terminal of the first transistor. Herein, the second transistor is configured to sink a first current from the control terminal of the first transistor when an output current of the power transistor exceeds a threshold value.

Abstract: A power amplifier includes: a power transistor to receive a power voltage; a first transistor including a first terminal to provide a bias current to the power transistor; and an overpower protection circuit to generate a first current corresponding to the power voltage and to provide the first current to a second terminal of the first transistor. The overpower protection circuit includes: a limiting current source to provide a limiting current to the second terminal of the first transistor; and a sink current generating circuit including a second transistor that includes a control terminal to which a voltage corresponding to the power voltage is applied and a first terminal connected to the second terminal of the first transistor, and to sink a second current from the limiting current.

Abstract: An overcurrent protection circuit includes a variable voltage source configured to generate a first voltage which that in response to a variable current; an amplifier comprising a first input terminal to which the first voltage is applied; and a limit current source connected to a second input terminal of the amplifier and configured to generate a limit current corresponding to the first voltage.

Abstract: A power supply switch circuit is disclosed. The power supply switch circuit includes a first switch configured to switch a supply of a first power supply voltage to a power supply terminal of a power amplifier; and a switch driving circuit including a first transistor configured to turn on the first switch, and a second transistor configured to turn off the first switch. The switch driving circuit may further include a first resistor that is positioned on a turn-on path formed between the first transistor and the first switch when the first transistor is turned on.

Abstract: A power amplifier includes a power transistor configured to amplify an input radio-frequency (RF) signal, and a bias circuit configured to provide a bias current to the power transistor, and in a first power mode, detect a first signal corresponding to a first level or more in the input RF signal and generate the bias current corresponding to the first signal, or detect a second signal corresponding to a second level or less in the input RF signal and generate the bias current corresponding to the second signal, and in a second power mode, detect a third signal corresponding to a third level or more in the input RF signal and generate the bias current corresponding to the third signal, or detect a fourth signal corresponding to a fourth level or less in the input RF signal and generate the bias current corresponding to the fourth signal.

Abstract: A power supply switch circuit includes a first switch configured to supply a first power supply voltage to a power supply terminal of a power amplifier, a control voltage generator configured to compare a first voltage of the power supply terminal with a predetermined first reference voltage to generate a first control voltage higher than the first power supply voltage, and a switch controller configured to use the first control voltage to generate a switching driving signal controlling the first switch.

Abstract: A power supply switch circuit includes: a first switch to switch supply of a first power supply voltage to a power supply terminal of a power amplifier; a control voltage generator to generate a first control voltage through a charge pump operation, and to control the charge pump operation by comparing the first power supply voltage to a first voltage, which is a voltage of the power supply terminal; and a switch controller to generate a switching driving signal to control the first switch using the first control voltage.

Abstract: A power supply switch circuit includes a switch circuit including a first switch configured to switch a first power source voltage to a power supply terminal of a power amplifier, and a second switch configured to switch a second power source voltage to the power supply terminal; a switch controller configured to control the switch circuit; and a power supply circuit configured to supply a third power source voltage to the power supply terminal when a first voltage of the power supply terminal is lower than a predetermined second voltage.

Abstract: A power source switch circuit and an operation method thereof are provided. The power source switch circuit may include a switch circuit that includes a first switch configured switch a supply of a voltage from a first power supply circuit to a power supply terminal of a power amplifier, and a second switch configured to switch a supply of a voltage from a second power supply circuit to the power supply terminal of the power amplifier; and a switch controller configured to control the switch circuit to set the first switch and the second switch in a turned-on state during a first period when the first switch is turned off and the second switch is turned on.

Abstract: A power supply switch circuit includes a first transistor that switches supplying of a first power supply voltage to a power supply terminal of a power amplifier, a switch controller that controls the first transistor and to which a second power supply voltage is applied, and a voltage selector that selects a higher voltage among the first power supply voltage and the second power supply voltage. The selected higher voltage is applied to a body terminal of the first transistor or a gate terminal of the first transistor.

Abstract: A bias timing control circuit includes a current source, a bias switch circuit, a duty cycle sensing circuit, and a switching control circuit. The bias switch circuit includes a first path switch, connected between an output node of the current source and a bias amplifying circuit, and a second path switch, connected between the output node of the current source and a temperature compensation circuit. The duty cycle sensing circuit is configured to generate a timing control signal based on a duty cycle of a transmission enable signal. The switching control circuit is configured to control a first turn-on time of the first path switch during an initial startup period, and a second turn-on time of the second path switch during a normal driving period subsequent to the initial startup period to adjust a warm-up time of a power amplifying circuit based on the timing control signal.

Abstract: An amplifying apparatus is provided. The amplifying apparatus comprises an amplifying circuit comprising a power amplifier and a bias circuit, the bias circuit is configured to detect an ambient temperature of the power amplifier to output a temperature voltage and regulate an internal current based on an input control signal to supply a bias current obtained by the regulation to the power amplifier; and a temperature control circuit that generates the control signal based on the temperature voltage during initial driving from a transmission mode starting point in time to an input point in time at which an input signal is input and outputting the control signal to the amplifying circuit.

Abstract: A power amplifier device includes a bias circuit to generate a startup current, which is based on an internal voltage and a startup voltage, during a startup time prior to a steady driving time point, and to generate a bias current, which is based on the internal voltage, after the steady driving time point, and a startup circuit to supply the bias circuit with the startup voltage during the startup time.

Abstract: A bias timing control circuit includes a current source, a bias switch circuit, a duty cycle sensing circuit, and a switching control circuit. The bias switch circuit includes a first path switch, connected between an output node of the current source and a bias amplifying circuit, and a second path switch, connected between the output node of the current source and a temperature compensation circuit. The duty cycle sensing circuit is configured to generate a timing control signal based on a duty cycle of a transmission enable signal. The switching control circuit is configured to control a first turn-on time of the first path switch during an initial startup period, and a second turn-on time of the second path switch during a normal driving period subsequent to the initial startup period to adjust a warm-up time of a power amplifying circuit based on the timing control signal.

Abstract: A road damage control system of the present invention includes a load detector that detects a load applied to a road from a vehicle on the road, and a server including a hardware processor that calculates road damage from the load obtained by the load detector, accumulates the calculated road damage to calculate accumulated road damage, estimates a road life from an allowable total road damage amount and the accumulated road damage, and outputs information about traffic regulation to be performed on the road to extend the estimated road life.

Abstract: A road damage calculation system of the present invention includes a load detector that detects a load applied to a road from a vehicle on the road, and a server including a hardware processor that calculates road damage from the load obtained by the load detector and accumulates the calculated road damage to calculate accumulated road damage.

Abstract: An amplifying apparatus is provided. The amplifying apparatus comprises an amplifying circuit comprising a power amplifier and a bias circuit, the bias circuit is configured to detect an ambient temperature of the power amplifier to output a temperature voltage and regulate an internal current based on an input control signal to supply a bias current obtained by the regulation to the power amplifier; and a temperature control circuit that generates the control signal based on the temperature voltage during initial driving from a transmission mode starting point in time to an input point in time at which an input signal is input and outputting the control signal to the amplifying circuit.