A first terminal receives a first DC voltage. A switch selectively couples the first terminal to a second terminal providing an output. A control circuit selectively actuates the switch in response to a comparison of the first DC voltage to a second DC voltage. A low-dropout (LDO) linear voltage regulator, connected between the first and third terminals, operates to provide the second DC voltage from the first DC voltage.

Provided is a reverse current switch. The reverse current switch includes: a comparison unit including a first input end, a second input end, and a first output end; and a switch resistance unit, where a first end of the switch resistance unit is connected to the first input end, a second end of the switch resistance unit is connected to the second input end, and a third end of the switch resistance unit is connected to the output end of the comparison unit, and the switch resistance unit is controlled by a voltage of the first output end. This reverse current switch has a simple structure and can implement working under low voltage conditions.

A capacitive-coupled level shifter includes a capacitive divider circuit having a first capacitive divider branch configured to couple a first input terminal to a first comparator terminal and a second capacitive divider branch configured to couple a second input terminal to a second comparator terminal. The first capacitive divider branch and the second capacitive divider branch are symmetric so as to cancel out a common mode voltage of a modulated signal input to the capacitive divider circuit. A level shifter system which includes the capacitive-coupled level shifter is also described.

A circuit arrangement is disclosed for controlling the switching of a field effect transistor (FET). A current controlled amplifier may be configured to amplify a current in a current sense device to generate an amplified current, wherein the current in the current sense device indicates a current through the FET. A comparator may be coupled to the current sense amplifier to compare a voltage corresponding to the amplified current with a voltage reference and to generate a comparator output based on the comparison, wherein the comparator output controls whether the FET is on or off.

To provide a hysteresis comparator having a small circuit area and low power consumption. The hysteresis comparator includes a comparator, a switch, a first capacitor, a second capacitor, and a logic circuit. A first terminal of the switch is electrically connected to one of a pair of conductive regions of the first capacitor, one of a pair of conductive regions of the second capacitor, and a first input terminal of the comparator. An output terminal of the comparator is electrically connected to an input terminal of the logic circuit. An output terminal of the logic circuit is electrically connected to the other of the pair of conductive regions of the second capacitor. The logic circuit has a function of generating an inverted signal of a signal input to the input terminal of the logic circuit and outputting the inverted signal to the output terminal of the logic circuit. A reference potential is input to the first input terminal of the comparator and the reference potential is held by the switch. Due to change in the potential of the output terminal of the comparator, the reference potential is changed by capacitive coupling of the second capacitor.

A sensing circuit includes: a comparison circuit for comparing an input signal to a corresponding limit threshold; and a control circuit for periodically selecting the limit threshold and sampling a comparison result to execute an interval determination step, thus determining an interval of the input signal. The interval determination step includes steps S100 and S200. Step S100: when the input signal is higher than an ascending upper limit threshold for consecutive plural times, assigning a higher adjacent interval as a following interval; when the input signal is lower than a descending lower limit threshold for consecutive plural times, assigning a lower adjacent interval as a following interval; and executing the interval determination step corresponding to the following interval. Step S200: When no adjacent interval is assigned as the following interval, generating an interval output signal corresponding to the interval and entering the corresponding step S100.

Control circuitry for controlling a current through an inductor of a power converter, the control circuitry comprising: comparison circuitry configured to compare a measurement signal, indicative of a current through the inductor during a charging phase of the power converter, to a signal indicative of a target average current through the inductor for the charging phase and to output a comparison signal based on said comparison; detection circuitry configured to detect, based on the comparison signal, a crossing time indicative of a time at which the current through the inductor during the charging phase is equal to the target average current for the charging phase; and current control circuitry configured to control a current through the inductor during a subsequent charging phase based on the crossing time.

A semiconductor device includes: a first input to which an input signal is input; a second input to which a reference signal is input; and a comparison stage which includes a current source connected to a first potential and first and second current path parts connected between the current source and a second potential different from the first potential and performing a comparison operation in response to the input signal and the reference signal, wherein the first and second current path parts respectively include first and second input circuits which are connected to the current source and first and second load circuits which are connected between the second potential and the first and second input circuits, wherein the first input circuit includes a first signal transistor and a first reference transistor, and wherein the second input circuit includes a second signal transistor and a second reference transistor.

A controller for a switching converter has a hysteresis generating circuit to provide an upper hysteresis limit and a lower hysteresis limit based on an output voltage, a switching control circuit for providing a switching control signal, and a frequency locking circuit for adjusting one of the upper hysteresis limit and the lower hysteresis limit based on the switching control signal and a clock signal. When the switching converter is in a first mode, a main switch of the switching converter is turned ON by comparing a current sense signal representative of a current flowing through the main switch with the lower hysteresis limit, and is turned OFF by comparing the current sense signal with the upper hysteresis limit. When the switching converter is in a second mode, the main switch is turned ON based on the clock signal, and is turned OFF based on the current sense signal.

An apparatus includes a first control circuit having an output and including a first comparator and a second control circuit coupled to the output of the first control circuit. The second control circuit includes a second comparator configured to: compare a first value to a reference frequency value, the first value indicating a frequency of a signal at the output of the first control circuit; and provide an adjustment value to change a hysteresis window of the first comparator.