Abstract: Embodiments of the present disclosure provide a chopper amplifier circuit that includes an operational amplifier, and a notch filter to be operated by a chopping pulse. The notch filter has a first branch that has a first capacitor, and a second branch that has a second capacitor. A chopping delay switch is connected to the first branch and the second branch of the notch filter. A control circuit is to close the chopping delay switch to short-circuit the first branch and the second branch of the notch filter to each other. The control circuit is to detect establishment of feedback signal at the chopper amplifier. The control circuit is to open the chopping delay switch, responsive to detecting establishment of the feedback signal at the chopper amplifier.

Abstract: Embodiments of the present disclosure provide a chopper amplifier circuit that includes an operational amplifier, and a notch filter to be operated by a chopping pulse. The notch filter has a first branch that has a first capacitor, and a second branch that has a second capacitor. A chopping delay switch is connected to the first branch and the second branch of the notch filter. A control circuit is to close the chopping delay switch to short-circuit the first branch and the second branch of the notch filter to each other. The control circuit is to detect establishment of feedback signal at the chopper amplifier. The control circuit is to open the chopping delay switch, responsive to detecting establishment of the feedback signal at the chopper amplifier.

Abstract: A power supply device that includes a switch circuit to which an input voltage is supplied, a coil coupled between the switch circuit and an output terminal from which an output voltage is outputted. A voltage adding circuit adds a slope voltage to a reference voltage. A control unit compares a feedback voltage corresponding to the output voltage and the reference voltage and switches the switch circuit at a timing corresponding to a comparison result of the feedback voltage and the reference voltage. A slope adjustment circuit differentiates a current flowing in the coil and adjusts a slope amount of the slope based on a differentiation result of the current.

Abstract: A power supply device that includes a switch circuit to which an input voltage is supplied, a coil coupled between the switch circuit and an output terminal from which an output voltage is outputted. A voltage adding circuit adds a slope voltage to a reference voltage. A control unit compares a feedback voltage corresponding to the output voltage and the reference voltage and switches the switch circuit at a timing corresponding to a comparison result of the feedback voltage and the reference voltage. A slope adjustment circuit differentiates a current flowing in the coil and adjusts a slope amount of the slope based on a differentiation result of the current.

Abstract: A power supply device that includes a switch circuit to which an input voltage is supplied, a coil coupled between the switch circuit and an output terminal from which an output voltage is outputted. A voltage adding circuit adds a slope voltage to a reference voltage. A control unit compares a feedback voltage corresponding to the output voltage and the reference voltage and switches the switch circuit at a timing corresponding to a comparison result of the feedback voltage and the reference voltage. A slope adjustment circuit differentiates a current flowing in the coil and adjusts a slope amount of the slope based on a differentiation result of the current.

Abstract: A power supply device that includes a switch circuit to which an input voltage is supplied, a coil coupled between the switch circuit and an output terminal from which an output voltage is outputted. A voltage adding circuit adds a slope voltage to a reference voltage. A control unit compares a feedback voltage corresponding to the output voltage and the reference voltage and switches the switch circuit at a timing corresponding to a comparison result of the feedback voltage and the reference voltage. A slope adjustment circuit differentiates a current flowing in the coil and adjusts a slope amount of the slope based on a differentiation result of the current.

Abstract: A power supply apparatus is provided which includes: a first switch provided between an inductor and a terminal to which a reference voltage is applied; a second switch provided between the inductor and an output terminal; a first comparator circuit that compares an input voltage with a first comparison voltage; a signal generating circuit that outputs a frequency signal according to an output from the first comparator circuit; and a first control circuit that controls the first and second switches based on an output from the signal generating circuit to control an electrical current flowing into the inductor.

Abstract: A power supply circuit includes an output transistor including a source coupled to power supply voltage, and a drain from which output voltage is outputted; a first error amplifier powered by the power supply voltage and outputting a signal based on a potential difference between the output voltage and a reference voltage; a buffer transistor including a gate coupled to the output of the first error amplifier, and a source coupled via a constant current source to the power supply voltage and coupled to a gate of the output transistor; a current detection transistor coupled to the output transistor such that a gate and source are shared; and an overcurrent protection circuit configured to limit the drain current of the buffer transistor based on the increase of the drain current of the current detection transistor and thereby control the output current of the output transistor.

Abstract: A power supply circuit includes an output transistor including a source coupled to power supply voltage, and a drain from which output voltage is outputted; a first error amplifier powered by the power supply voltage and outputting a signal based on a potential difference between the output voltage and a reference voltage; a buffer transistor including a gate coupled to the output of the first error amplifier, and a source coupled via a constant current source to the power supply voltage and coupled to a gate of the output transistor; a current detection transistor coupled to the output transistor such that a gate and source are shared; and an overcurrent protection circuit configured to limit the drain current of the buffer transistor based on the increase of the drain current of the current detection transistor and thereby control the output current of the output transistor.

Abstract: A power supply apparatus is provided which includes: a first switch provided between an inductor and a terminal to which a reference voltage is applied; a second switch provided between the inductor and an output terminal; a first comparator circuit that compares an input voltage with a first comparison voltage; a signal generating circuit that outputs a frequency signal according to an output from the first comparator circuit; and a first control circuit that controls the first and second switches based on an output from the signal generating circuit to control an electrical current flowing into the inductor.

Abstract: A power supply circuit includes an output transistor including a source coupled to power supply voltage, and a drain from which output voltage is outputted; a first error amplifier powered by the power supply voltage and outputting a signal based on a potential difference between the output voltage and a reference voltage; a buffer transistor including a gate coupled to the output of the first error amplifier, and a source coupled via a constant current source to the power supply voltage and coupled to a gate of the output transistor; a current detection transistor coupled to the output transistor such that a gate and source are shared; and an overcurrent protection circuit configured to limit the drain current of the buffer transistor based on the increase of the drain current of the current detection transistor and thereby control the output current of the output transistor.

Abstract: A power supply apparatus is described that includes a first switch, a second switch, a first comparator, a signal generator and a controller. The first switch is provided between an inductor and a terminal having a reference voltage. The second switch is provided between the inductor and an output terminal. The first comparator compares an input voltage and a first comparison voltage. The signal generator outputs a frequency signal based on an output of the first comparator. The first controller controls current flowing into the inductor by controlling the first switch and the second switch based on the output of the signal generator.

Abstract: In an input transistor of current mirror circuit, it is intended to prevent the current generated by Early effects from appearing in the output current of the current mirror circuit. Having an Early voltage detector 22 of same connection and structure as a driver circuit 21, and connected in parallel to the driver circuit 21, the current flowing in input transistor Q9 of the Early voltage detector 22 is detected. Output current (current IQ11) of Early voltage detector 22 is added to input current (current IQ5) of driver circuit 21. As a result, in input current (current IQ7) of current mirror circuit 25, current ? due to Early voltage effects can be canceled. At the same time, current ? due to Early voltage effects generated in input transistor Q5 of current mirror circuit 25 is prevented from appearing in output current (current IQ8) of current mirror circuit 25.

Abstract: In a DC-DC converter of synchronous rectifying system, a control circuit of DC-DC converter capable of improving the control voltage value of output voltage at light load and enhancing the power conversion efficiency, and its control method are presented. An inverting input terminal of comparator COMP2 of which non-inverting input terminal is connected to a grounding potential is connected to one terminal of choke coil L1 by way of terminal (X). An output terminal (N1) of comparator COMP2 is connected to a delay circuit DL, and an output terminal (N2) of delay circuit DL is connected to AND gate circuit AND1. The delay circuit DL is a circuit for delaying the transition from high level to low level of input terminal (N1). Excessive power supplied more than demanded by the load at light load is returned to choke coil L1. Elevation of output voltage VOUT due to excess power accumulated in output capacitor C1 can be suppressed.

Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.

Abstract: In an input transistor of current mirror circuit, it is intended to prevent the current generated by Early effects from appearing in the output current of the current mirror circuit. Having an Early voltage detector 22 of same connection and structure as a driver circuit 21, and connected in parallel to the driver circuit 21, the current flowing in input transistor Q9 of the Early voltage detector 22 is detected. Output current (current IQ11) of Early voltage detector 22 is added to input current (current IQ5) of driver circuit 21. As a result, in input current (current IQ7) of current mirror circuit 25, current ? due to Early voltage effects can be canceled. At the same time, current ? due to Early voltage effects generated in input transistor Q5 of current mirror circuit 25 is prevented from appearing in output current (current IQ8) of current mirror circuit 25.

Abstract: Provides a switching regulator control circuit, a switching regulator and a switching regulator control method for achieving low current consumption and quick response at normal operating time. A change-over switch MFB for opening/closing the phase compensation is provided to establish both the quick responsibility using a gain of an error amplifier EA provided with no phase compensation and stability of control system provided with phase compensation. By turning the change-over switch MFB non-conductive at a timing in which the PMOS transistor M1 turns to conductive, the phase compensation between the input and output of the error amplifier EA is cut off. A detection voltage VM is amplified in term of error with a gain of the error amplifier EA itself. A quick transient response to changes in the output voltage VOUT is achieved corresponding to maximum response characteristic.

Abstract: In a DC-DC converter of synchronous rectifying system, a control circuit of DC-DC converter capable of improving the control voltage value of output voltage at light load and enhancing the power conversion efficiency, and its control method are presented. An inverting input terminal of comparator COMP2 of which non-inverting input terminal is connected to a grounding potential is connected to one terminal of choke coil L1 by way of terminal (X). An output terminal (N1) of comparator COMP2 is connected to a delay circuit DL, and an output terminal (N2) of delay circuit DL is connected to AND gate circuit AND1. The delay circuit DL is a circuit for delaying the transition from high level to low level of input terminal (N1). Excessive power supplied more than demanded by the load at light load is returned to choke coil L1. Elevation of output voltage VOUT due to excess power accumulated in output capacitor C1 can be suppressed.

Abstract: Provides a switching regulator control circuit, a switching regulator and a switching regulator control method for achieving low current consumption and quick response at normal operating time. A change-over switch MFB for opening/closing the phase compensation is provided to establish both the quick responsibility using a gain of an error amplifier EA provided with no phase compensation and stability of control system provided with phase compensation. By turning the change-over switch MFB non-conductive at a timing in which the PMOS transistor M1 turns to conductive, the phase compensation between the input and output of the error amplifier EA is cut off. A detection voltage VM is amplified in term of error with a gain of the error amplifier EA itself. A quick transient response to changes in the output voltage VOUT is achieved corresponding to maximum response characteristic.

Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.