A current-limiting protection circuit and an electronic device are provided. The current-limiting protection circuit includes a power supply chip and a current-limiting circuit that is electrically connected to the power supply chip. The current-limiting circuit is configured to detect a charging current, and output a feedback voltage to the power supply chip. The power supply chip is configured to when the feedback voltage is greater than a second reference voltage, reduce an output voltage until the charging current reaches a preset value, where the second reference voltage is a preset internal voltage of the power supply chip.

Disclosed is a low dropout linear voltage regulator and a control circuit thereof. The control circuit comprises an error amplifier, a foldback current-limiting protection circuit, an undershoot suppression circuit and an output detection circuit. The foldback current-limiting protection circuit limits the output current of power transistor and performs short circuit protection, the undershoot suppression circuit pulls the control terminal of the power transistor to low voltage level when the output voltage undershoots. The output detection circuit judges whether the output voltage rises to a preset voltage value in the startup stage, and before the output voltage rises to the preset voltage value, disables the undershoot suppression circuit and the foldback characteristic of the foldback current-limiting protection circuit, which can prevent normal startup of the circuit from being affected by a maloperation of the foldback current-limiting protection circuit and the undershoot suppression circuit during the startup process, improve on-load startup ability.

A method and apparatuses for power regulation using an extended current limit are disclosed. The power regulator detects an occurrence of an output current of the regulator exceeding a first current limit, triggers an extended current limit timer based on the detected occurrence, regulates the output current according to a second current limit higher than the first current limit based on a duration of the extended current limit timer, and regulates the output current according to the first current limit based on an expiration of the duration of the extended current limit timer.

A circuit is provided with inrush current protection through control of the output current at start-up by a current source that does not rely on the output capacitor and which provides a smooth transition from a controlled current mode during a start-up phase to a voltage regulation mode.

Apparatus disclosed herein implement a fast transient precision current limiter such as may be included in an electronic voltage regulator. The current limiter includes two current sense element/current clamp control loops. A fast response time control loop first engages and clamps a current spike. A precision control loop then engages to more accurately clamp the output current to a programmed set point. The precision clamping loop includes an inner loop to linearize the precision current sense element. The inner loop forces the drain-to-source voltage (VDS) of the precision sense element to track the VDS of the regulator pass element. A more precise clamping operation results. Overall speed is not sacrificed as the fast response time clamping loop operates in parallel to protect circuitry while the precision clamping loop engages.

A module level power electronics (MLPE) photovoltaic system and a method for photovoltaic string control are provided. The method is applied to a control unit in the MLPE photovoltaic system. The control unit detects an output current of each photovoltaic string in the MLPE photovoltaic system, and then controls, for photovoltaic strings connected in parallel to a same inverter in the MLPE photovoltaic system, a voltage of a photovoltaic string with larger output current to be reduced, or controls a voltage of a photovoltaic string with smaller output current to be increased, so that backflow current can be reduced to preset range tolerable for MLPE device. The method is from a perspective of the MLPE photovoltaic system, the backflow current is limited by controlling voltage change of associated photovoltaic string without additional hardware cost, effectively protecting MLPE device in the MLPE photovoltaic system.

A method and apparatuses for power regulation using an extended current limit are disclosed. The power regulator detects an occurrence of an output current of the regulator exceeding a first current limit, triggers an extended current limit timer based on the detected occurrence, regulates the output current according to a second current limit higher than the first current limit based on a duration of the extended current limit timer, and regulates the output current according to the first current limit based on an expiration of the duration of the extended current limit timer.

Examples are disclosed herein that relate to automatically limiting an output current of a voltage regulator circuit responsive to detecting that the voltage regulator is in a current overload mode. In one example, a voltage regulator circuit includes an amplifier stage and a current limiter stage electrically connected to an output of the amplifier stage. The amplifier stage is configured to output a DC voltage based on a reference voltage and feedback from an output voltage. The current limiter stage is configured to operate in a quiescent mode and an overload mode. In the quiescent mode, the current limiter stage is configured to operate as a buffer stage that forms a closed feedback loop to an input of the amplifier stage. In the overload mode, the current limiter stage is configured to act as a current source that clamps an output current to a designated current.

Examples are disclosed herein that relate to automatically limiting an output current of a voltage regulator circuit responsive to detecting that the voltage regulator is in a current overload mode. In one example, a voltage regulator circuit includes an amplifier stage and a current limiter stage electrically connected to an output of the amplifier stage. The amplifier stage is configured to output a DC voltage based on a reference voltage and feedback from an output voltage. The current limiter stage is configured to operate in a quiescent mode and an overload mode. In the quiescent mode, the current limiter stage is configured to operate as a buffer stage that forms a closed feedback loop to an input of the amplifier stage. In the overload mode, the current limiter stage is configured to act as a current source that clamps an output current to a designated current.

A module level power electronics (MLPE) photovoltaic system and a method for photovoltaic string control are provided. The method is applied to a control unit in the MLPE photovoltaic system. The control unit detects an output current of each photovoltaic string in the MLPE photovoltaic system, and then controls, for photovoltaic strings connected in parallel to a same inverter in the MLPE photovoltaic system, a voltage of a photovoltaic string with larger output current to be reduced, or controls a voltage of a photovoltaic string with smaller output current to be increased, so that backflow current can be reduced to preset range tolerable for MLPE device. The method is from a perspective of the MLPE photovoltaic system, the backflow current is limited by controlling voltage change of associated photovoltaic string without additional hardware cost, effectively protecting MLPE device in the MLPE photovoltaic system.