Abstract: A switching power supply device includes: a switching output circuit configured to generate an output voltage from an input voltage; an oscillation circuit configured to generate a clock signal; a control circuit configured to control driving of the switching output circuit in synchronization with the clock signal; a pulse-by-pulse type overcurrent protection circuit configured to detect an overcurrent flowing through the switching output circuit to generate an overcurrent protection signal for forcibly stopping a switching operation of the switching output circuit; and a pulse skip circuit configured to perform a pulse skip operation of the clock signal in response to the overcurrent protection signal.

Abstract: A control device serves as an agent that controls a switching regulator including an output switch and a synchronous rectification switch. The control device includes: a summator generating a sum sense signal by adding up a first sense signal commensurate with the current passing in the output switch and a second sense signal commensurate with the current passing in the synchronous rectification switch; a smoother generating a smoothed sense signal by smoothing the sum sense signal; and a switch driver driving the output switch and the synchronous rectification switch complementarily through current mode control based on the smoothed sense signal.

Abstract: A switching power supply device includes: a switching output circuit configured to generate an output voltage from an input voltage; an oscillation circuit configured to generate a clock signal; a control circuit configured to control driving of the switching output circuit in synchronization with the clock signal; a pulse-by-pulse type overcurrent protection circuit configured to detect an overcurrent flowing through the switching output circuit to generate an overcurrent protection signal for forcibly stopping a switching operation of the switching output circuit; and a pulse skip circuit configured to perform a pulse skip operation of the clock signal in response to the overcurrent protection signal.

Abstract: A switching power supply device includes: a switching output circuit configured to generate an output voltage from an input voltage; an oscillation circuit configured to generate a clock signal; a control circuit configured to control driving of the switching output circuit in synchronization with the clock signal; a pulse-by-pulse type overcurrent protection circuit configured to detect an overcurrent flowing through the switching output circuit to generate an overcurrent protection signal for forcibly stopping a switching operation of the switching output circuit; and a pulse skip circuit configured to perform a pulse skip operation of the clock signal in response to the overcurrent protection signal.

Abstract: A switching power source apparatus includes: a switching output circuit that generates an output voltage from an input voltage; an error amplifier that generates an error voltage in accordance with a difference between a predetermined reference voltage and the output voltage or a feedback voltage corresponding to the output voltage; a clock signal generation circuit that generates a clock signal; a slope voltage generation circuit that receives the clock signal to generate a slope voltage; a delay circuit that delays the clock signal to generate an on-signal; a PWM comparator that compares the error voltage and the slope voltage with each other to generate an off-signal; a logic circuit that receives the on-signal and off-signal to generate a pulse width modulation signal; and a switch drive circuit that receives the pulse width modulation signal to generate a drive signal for the switching output circuit.

Abstract: A switching power supply device includes: a switching output circuit configured to generate an output voltage from an input voltage; an oscillation circuit configured to generate a clock signal; a control circuit configured to control driving of the switching output circuit in synchronization with the clock signal; a pulse-by-pulse type overcurrent protection circuit configured to detect an overcurrent flowing through the switching output circuit to generate an overcurrent protection signal for forcibly stopping a switching operation of the switching output circuit; and a pulse skip circuit configured to perform a pulse skip operation of the clock signal in response to the overcurrent protection signal.

Abstract: A switching power supply device includes a switching output circuit, an error amplifier, a slope voltage generating circuit, a PWM comparator, a logic circuit, a switch driving circuit, and a reverse current detection circuit. The slope voltage generating circuit increases a slope voltage from a reset level with a gradient corresponding to an input voltage during an on period of the output transistor, and maintains the slope voltage at an offset level corresponding not to the reset level but to an output voltage during an off period of the output transistor.

Abstract: A switching power supply device includes a switching output circuit, an error amplifier, a slope voltage generating circuit, a PWM comparator, a logic circuit, a switch driving circuit, and a reverse current detection circuit. The slope voltage generating circuit increases a slope voltage from a reset level with a gradient corresponding to an input voltage during an on period of the output transistor, and maintains the slope voltage at an offset level corresponding not to the reset level but to an output voltage during an off period of the output transistor.

Abstract: A switching regulator includes a load determination circuit. The load determination circuit feeds, to an offset voltage generation circuit, a different load determination signal at the time of light load or at the time of heavy load. The offset voltage generation circuit applies an offset voltage corresponding to whether a load is light or heavy to the inverting input terminal of a PWM comparator to acquire the responsiveness and the stability of the switching regulator.

Abstract: A switching power source apparatus includes: a switching output circuit that generates an output voltage from an input voltage; an error amplifier that generates an error voltage in accordance with a difference between a predetermined reference voltage and the output voltage or a feedback voltage corresponding to the output voltage; a clock signal generation circuit that generates a clock signal; a slope voltage generation circuit that receives the clock signal to generate a slope voltage; a delay circuit that delays the clock signal to generate an on-signal; a PWM comparator that compares the error voltage and the slope voltage with each other to generate an off-signal; a logic circuit that receives the on-signal and off-signal to generate a pulse width modulation signal; and a switch drive circuit that receives the pulse width modulation signal to generate a drive signal for the switching output circuit.

Abstract: A switching regulator includes a load determination circuit. The load determination circuit feeds, to an offset voltage generation circuit, a different load determination signal at the time of light load or at the time of heavy load. The offset voltage generation circuit applies an offset voltage corresponding to whether a load is light or heavy to the inverting input terminal of a PWM comparator to acquire the responsiveness and the stability of the switching regulator.

Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

Abstract: A base isolation structure capable of securing stable operation since there is no such a possibility that micro-vibration usually produced does not exceed a requested allowable vibration value by developing base isolating effects in earthquake to prevent heavy damages from occurring and effectively isolating a structure in which vibration-sensitive equipments are disposed such as a semiconductor manufacturing plant from earthquake. A base isolation device (4) by a rigid sliding bearing having such a rigidity in the vertical and horizontal directions that micro vibration transmitted to the structure (1) can be reduced to a value smaller than the allowable vibration value determined according to the degree of the reluctance of the equipments is disposed between the structure (1) in which the micro vibration-sensitive equipments are disposed and the foundation (3) of the structure.