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.

The present disclosure presents a current limiter, a method of operating the same, and a hotswap module comprising the same. The current limiter comprises: a current limiting module having an input terminal, an output terminal, and a control terminal, and configured to limit a current, which is input via its input terminal, within a current limiting range; and a range controlling module having a control terminal coupled top the control terminal of the current limiting module and a sensing terminal coupled to the output terminal of the current limiting module, and configured to generate a control signal at least based on the current which is output via the output terminal of the current limiting module and which is sensed at the sensing terminal, and output the control signal via its control terminal, such that the current limiting range is dynamically adjustable based on the control signal.

An apparatus includes a power transistor to conduct a load current from a supply voltage node to an output node and a current sense circuit coupled to the power transistor. The current sense circuit generates a current sense current proportional to the load current. A temperature sense circuit is included to generate a temperature sense voltage proportional to the temperature of the power FET. A thermal limit circuit is coupled to the temperature sense circuit. A current limit circuit is coupled to the current sense circuit and to the thermal limit circuit. The current limit circuit generates a control signal on a current limit circuit output node. The control signal is responsive to the current sense current and to a first current from the thermal limit circuit. The current limit circuit output node is coupled to a control input of the power transistor.

An apparatus includes a power transistor to conduct a load current from a supply voltage node to an output node and a current sense circuit coupled to the power transistor. The current sense circuit generates a current sense current proportional to the load current. A temperature sense circuit is included to generate a temperature sense voltage proportional to the temperature of the power FET. A thermal limit circuit is coupled to the temperature sense circuit. A current limit circuit is coupled to the current sense circuit and to the thermal limit circuit. The current limit circuit generates a control signal on a current limit circuit output node. The control signal is responsive to the current sense current and to a first current from the thermal limit circuit. The current limit circuit output node is coupled to a control input of the power transistor.

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.

Embodiments include techniques for automatically restarting a voltage foldback circuit, the techniques include operating a circuit, and detecting a condition of the circuit. The techniques also include performing a foldback operation based at least in part on the condition of the circuit, subsequently detecting the condition of the circuit. The techniques include initiating a timer of the circuit based at least in part on the subsequent detection of the circuit, and returning the circuit to normal operation based on the timer.

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.

An overcurrent protection circuit includes, for example, a first node to which the first electrode of an overcurrent sense resistor is connected, a second node to which the second electrode of the overcurrent sense resistor and the main electrode of an output transistor are connected, a third node to which the control electrode of the output transistor is connected, a voltage source generating a reference voltage by adding or subtracting an offset voltage to or from the terminal voltage at the first node, a hysteresis setting resistor and an overcurrent protection transistor connected in series between the second node and the third node to output a sense voltage from a fourth node between them, and an operational amplifier controlling the overcurrent protection transistor according to the difference between the reference voltage and the sense voltage.

A constant voltage generator circuit includes a first amplifier circuit that drives a transistor controlling an output current based on a reference voltage; a second amplifier circuit that drives the transistor based on the reference voltage from the power source; a protection circuit that limit an output current flowing through the load from the transistor; and a control circuit that controls operation of the second amplifier circuit. The control circuit controls the second amplifier circuit to operate or not to operate based on a relationship between the output current and predetermined first or second threshold. The second amplifier circuit further includes a first operation voltage potential fixing circuit that fixes an operation voltage potential of an internal node of the second amplifier circuit during non-operation thereof.

A power supply circuit includes an amplifier and first and second transistors. The amplifier is configured to provide a drive potential at its output. The first transistor is coupled between a voltage supply terminal and an output terminal, and has a first control terminal coupled to the amplifier output, and is configured to receive at least a portion of the drive potential at the first control terminal. The second transistor is coupled between the first control terminal and the output terminal, and has a second control terminal coupled to the amplifier output. A threshold voltage of the first transistor is lower than a threshold voltage of the second transistor. The second transistor can operate to adaptively reduce the portion of the drive potential at the first control terminal, for example, by the second transistor turning on responsive to a voltage at the output terminal being lower than a voltage level.