According to a first aspect of the present disclosure, a power switching circuit is provided, comprising: a bandgap reference circuit configured to receive an input voltage and to generate a reference voltage in response to receiving said input voltage; a supply selection circuit configured to receive at least two supply voltages, to select the highest voltage of said supply voltages and to provide said highest voltage to the bandgap reference circuit. According to a second aspect of the present disclosure, a corresponding method of operating a power switching circuit is conceived.

Embodiments disclosed herein include combining power from isolated power paths for powering remote units in distributed antenna systems (DASs). In one example, a remote unit(s) is configured to include multiple input power ports for receiving power from multiple power paths. The received power from each input power port is combined to provide a combined output power for powering the remote unit. Thus, a remote unit can be powered by the combined output power. To avoid differences in received power on the multiple input power ports causing a power supply to supply higher power than designed or regulated, the input power ports in the remote unit are electrically isolated from each other. Further, the received power on the multiple power inputs ports can be controlled to be proportionally provided to the combined output power according to the maximum power supplying capabilities of the respective power supplies.

A semiconductor device which controls output of a plurality of voltages is provided. A power supply control circuit which drives the semiconductor device includes a reference voltage generating circuit and a stabilized power supply circuit. The stabilized power supply circuit has a function of outputting a voltage input from a sample-and-hold circuit and amplified by the amplifier circuit. A control circuit has a function of setting an output voltage of the power supply control circuit. The sample-and-hold circuit in the stabilized power supply circuit includes a transistor whose on/off state is controlled. In such a configuration, a voltage set by the control circuit can be held and output.

A semiconductor device which controls output of a plurality of voltages is provided. A power supply control circuit which drives the semiconductor device includes a reference voltage generating circuit and a stabilized power supply circuit. The stabilized power supply circuit has a function of outputting a voltage input from a sample-and-hold circuit and amplified by the amplifier circuit. A control circuit has a function of setting an output voltage of the power supply control circuit. The sample-and-hold circuit in the stabilized power supply circuit includes a transistor whose on/off state is controlled. In such a configuration, a voltage set by the control circuit can be held and output.

A voltage generation circuit includes: a periodic wave generator that generates an on/off signal that is periodically enabled/disabled, where at least one between a period and a duty cycle of the on/off signal is controlled based on at least one information among temperature information, capacitance information, leakage current information, speed information, and voltage level information; and an internal voltage generator that is enabled/disabled in response to the on/off signal and generates an internal voltage.

A voltage generation circuit includes: a periodic wave generator that generates an on/off signal that is periodically enabled/disabled, where at least one between a period and a duty cycle of the on/off signal is controlled based on at least one information among temperature information, capacitance information, leakage current information, speed information, and voltage level information; and an internal voltage generator that is enabled/disabled in response to the on/off signal and generates an internal voltage.

A power supply control device for a communication network includes: a monitoring module (11) and N voltage-adjustable Direct Current/Direct Current (DC/DC) modules (121, 122 . . . 12N). The monitoring module is configured to detect circuit data of each of power supply circuits (1,2, . . . i), compare the circuit data with each other, calculate an average value, analyse required output circuit data of each of the power supply circuits, and transmit the required output circuit data of the power supply circuits to respective the voltage-adjustable DC/DC modules. The voltage-adjustable DC/DC modules are configured to receive the required output circuit data of the power supply circuits, and adjust output voltages of the power supply circuits according to the output circuit data. Output ends of all of the voltage-adjustable DC/DC modules are connected in parallel to supply power to a subordinate electro-load. Also disclosed is a power supply control method for the communication network.

A power supply control device for a communication network includes: a monitoring module (11) and N voltage-adjustable Direct Current/Direct Current (DC/DC) modules (121, 122 . . . 12N). The monitoring module is configured to detect circuit data of each of power supply circuits (1,2, . . . i), compare the circuit data with each other, calculate an average value, analyse required output circuit data of each of the power supply circuits, and transmit the required output circuit data of the power supply circuits to respective the voltage-adjustable DC/DC modules. The voltage-adjustable DC/DC modules are configured to receive the required output circuit data of the power supply circuits, and adjust output voltages of the power supply circuits according to the output circuit data. Output ends of all of the voltage-adjustable DC/DC modules are connected in parallel to supply power to a subordinate electro-load. Also disclosed is a power supply control method for the communication network.

An electronic device 2 has circuitry 4 which operates in a first voltage domain 6 supplied with a first voltage level VDD1 and a reference voltage level. A voltage regulator 14 generates the first voltage level VDD1 from a second voltage level VDD2 higher than the first voltage level VDD1. At least one power gate 20, 30 is provided for selectively coupling the circuitry 4 to one of the first voltage level VDD1 or the reference level. The control signal 22 for the power gate 20, 30 is generated in a second voltage domain supplied with a higher voltage level VDD2 or VDD3 derived from the second voltage level VDD2 supplied to the voltage regulator 14. Hence, an existing high voltage source within the device 2 can be reused for applying a boosted voltage to power gates to improve efficiency of power gating.

An electronic device 2 has circuitry 4 which operates in a first voltage domain 6 supplied with a first voltage level VDD1 and a reference voltage level. A voltage regulator 14 generates the first voltage level VDD1 from a second voltage level VDD2 higher than the first voltage level VDD1. At least one power gate 20, 30 is provided for selectively coupling the circuitry 4 to one of the first voltage level VDD1 or the reference level. The control signal 22 for the power gate 20, 30 is generated in a second voltage domain supplied with a higher voltage level VDD2 or VDD3 derived from the second voltage level VDD2 supplied to the voltage regulator 14. Hence, an existing high voltage source within the device 2 can be reused for applying a boosted voltage to power gates to improve efficiency of power gating.