A power supply controller used in a DC/DC converter includes a feedback control unit that generates a pulse-shaped PWM signal having a first level that is one of a high level and a low level and a second level that is the other of the high level and the low level, on the basis of a feedback voltage based on an output voltage of the DC/DC converter; a low voltage detection unit that detects a low voltage of the feedback voltage; and a selection unit that chooses, as a chosen clock signal, a first clock signal having a high duty when the low voltage is not detected by the low voltage detection unit, and chooses a second clock signal having a low duty when the low voltage is detected by the low voltage detection unit. The feedback control unit includes a reset signal generation unit that generates a pulse-shaped reset signal having the first level and the second level, based on the feedback voltage, and a PWM signal generation unit that generates the PWM signal at the first level during a period that is an overlap between a period during which the reset signal is at the first level and a period during which the chosen clock signal is at the first level.

The present disclosure describes various aspects of adaptive current control in switching power regulators for fast transient response. In some aspects, a clock of a switching power regulator is prevented, in response to detecting a transient load, from affecting application of current to an inductor of the regulator. A first switch device applies current to the inductor of the regulator until inductor current reaches a maximum current level. A second switch device then enables the current to flow through the inductor until the inductor current reaches a current control signal based on an output voltage of the switching power regulator. In some aspects, an offset is also applied to the current control signal to further increase average inductor current. These operations may be repeated without interruption from the clock to quickly increase the inductor current, and thus current provided to the regulator output in response to the transient load.

A bi-directional voltage converter of a smart card includes switching elements connected between an input node and an output node and a start-up transistors whose channel width over channel length is smaller than a channel width over channel length of the switching element. The bi-directional voltage converter stores a driving voltage applied to an output node in a storage capacitor during a booting operation and provides the voltage stored in the storage capacitor to an input node. The bi-directional voltage converter may boost another driving voltage at the input node step-wisely and may perform bi-directional voltage converting with reduced occupied area and high efficiency.

A circuit device includes a pulse signal output circuit and a driving circuit. The pulse signal output circuit, when a detection voltage has decreased below a reference voltage, changes a pulse signal to an active level at which a switching element is turned on. The pulse signal output circuit, after the detection voltage has decreased below the reference voltage, performs monitoring as to whether or not the detection voltage has exceeded the reference voltage, and upon detecting that the detection voltage has exceeded the reference voltage, changes the pulse signal to an inactive level at which the switching element is turned off. The driving circuit outputs a driving signal based on the pulse signal to the switching element.

A control circuit for a switching converter, where: in a first operation state, the control circuit controls a switching period of the switching converter to remain unchanged, controls a turn-on time of a power transistor in the switching converter to be not less than a minimum turn-on time in each switching period, and controls a turn-off time of the power transistor to be not less than a minimum turn-off time; in a second operation state, the control circuit controls the turn-on time of the power transistor to be the minimum turn-on time in each switching period, and adjusts the switching period to further reduce a duty cycle; and in a third operation state, the control circuit controls the turn-off time of the power transistor to be the minimum turn-off time in each switching period, and adjusts the switching period to further increase the duty cycle.

The invention relates to a switching power supply converter, which comprising a transformer including a primary winding and a secondary winding, a power switch circuit and a voltage input circuit, a voltage output circuit, an auxiliary winding, a control circuit, and a voltage sensing circuit; the control circuit performs that in a first turn-off period of the power switch circuit, acquiring a first time duration from a preset delay after the power switch circuit turning off until the sensed voltage corresponding to a preset condition, and acquiring a difference between the first time duration and a preset time duration as a second time duration; in a second turn-off period of the power switch circuit, acquiring the sensed voltage at the time point corresponding to the end of the second time duration starting from the preset delay after the power switch circuit turning off as an effective sample.

An example controller for a flyback power converter includes a secondary-side circuit comprising a secondary-side controller. The secondary-side controller is configured to sense an electrical characteristic of a secondary-side output of the flyback power converter, select, based on the sensed electrical characteristic, a power mode, and transmit, over a communication channel, a control message specifying the selected power mode. A primary-side circuit of the controller includes a primary-side controller. The primary-side controller is configured to receive, over the communication channel, the control message specifying the selected power mode and control primary-side flyback drive circuitry of the primary-side circuit to drive a primary-side output of the flyback power converter according to the selected power mode so as to control a value of the electrical characteristic of the secondary-side output of the flyback power converter.

A power converter having a smooth transition control mechanism is provided. An oscillator circuit outputs a clock signal. A control circuit receives the clock signal from the oscillator circuit and outputs a control signal based on the clock signal. A driver circuit outputs a high-side conduction signal and a low-side conduction signal according to the control signal. A high-side switch is turned on or off according to the high-side conduction signal from the driver circuit. A low-side switch is turned on or off according to the low-side conduction signal from the driver circuit. The oscillator circuit receives the high-side conduction signal from the driver circuit. The oscillator circuit, according to the high-side conduction signal, determines whether or not the clock signal outputted to the control circuit needs to be adjusted.

A semiconductor device, for controlling a power supply which generates and outputs a driving pulse, includes: a clock generating circuit with an oscillating circuit in which a frequency can be changed and which generates a clock signal; a voltage/electric current control circuit which provides timing to turn off a switching element; a setting terminal to provide setting information from outside; a switch between a first power supply terminal and a second power supply terminal; and an internal power supply voltage control circuit which controls the switch. When voltage of the setting terminal is lower than a first voltage value, the device advances to a first stop mode in which output of a driving pulse is stopped. When voltage of the setting terminal is higher than the first voltage value, the device advances to a second stop mode in which the output of the driving pulse is stopped.

A system includes a switching converter, an input voltage source coupled to an input of the switching converter, and a load coupled to an output of the switching converter. The system also includes a load sense circuit coupled to the load and configured to provide a load sense signal. The system also includes an oscillator coupled to the switching converter and configured to provide a spread spectrum modulated (SSM) clock signal to the switching converter, wherein a frequency of the SSM clock signal varies as a function of the load sense signal.