Abstract: A protection device detects a temperature in a predetermined monitoring place in an electronic apparatus 3 to protect the electronic apparatus 3, and includes an oscillating circuit 20 for generating a clock signal Vck having a predetermined cycle and a predetermined ON time, and a temperature detection circuit 16 for detecting the temperature in the monitoring place during the ON time of the clock signal Vck. The protection device shuts off supply of electric power to the electronic apparatus 3, when the temperature in the monitoring place exceeds a predetermined temperature.

Abstract: A protection device detects a temperature in a predetermined monitoring place in an electronic apparatus 3 to protect the electronic apparatus 3, and includes an oscillating circuit 20 for generating a clock signal Vck having a predetermined cycle and a predetermined ON time, and a temperature detection circuit 16 for detecting the temperature in the monitoring place during the ON time of the clock signal Vck. The protection device shuts off supply of electric power to the electronic apparatus 3, when the temperature in the monitoring place exceeds a predetermined temperature.

Abstract: A step-up converter includes an inductor which receives input voltage Vi at one end, a first FET of the first conduction type which functions as a switch for determining whether or not energy is accumulated in the inductor, a second FET of the second conduction type which rectifies a current output from the other end of the inductor, an output capacitor having an end connected to the source of the second FET, a current detection circuit, and a feedback control circuit. The current detection circuit detects a current flowing through the first N-channel FET to output current detection signal Vc. The feedback control circuit controls the operations of the first N-channel FET and a P-channel FET based on current detection signal Vc.

Abstract: A current detection circuit of the present invention has a switching device 1; an auxiliary switching device 2; an offset voltage source comprising an offset resistor device 7 and a current source circuit 8; a compensation circuit, comprising a differential amplifier 4 and a compensation transistor 5, for adjusting the output current of the auxiliary switching device 2 so that the potential obtained by subtracting the voltage drop across the offset resistor device 7 from the output potential of the switching device 1 is equal to the output potential of the auxiliary switching device 2, being configured that the detection level of the current flowing in the switching device 1 is shifted by an offset amount.

Abstract: In a DC-DC converter conforming to the current mode control system, in which the valley value of an inductor current is controlled for output control, a current detection circuit 6 is configured to detect the current flowing from a low-side FET 2 to an inductor 3 using an FET 60, an NPN transistor 61, an NPN transistor 62, a PNP transistor 64, a PNP transistor 65 and a resistor 66, to detect the current flowing from the inductor 3 to the low-side FET 2 using an FET 67, a differential amplifier 68, an FET 69 and the resistor 66, and to output a current detection signal Vc.

Abstract: A current detection circuit of the present invention has a switching device 1; an auxiliary switching device 2; an offset voltage source comprising an offset resistor device 7 and a current source circuit 8; a compensation circuit, comprising a differential amplifier 4 and a compensation transistor 5, for adjusting the output current of the auxiliary switching device 2 so that the potential obtained by subtracting the voltage drop across the offset resistor device 7 from the output potential of the switching device 1 is equal to the output potential of the auxiliary switching device 2, being configured that the detection level of the current flowing in the switching device 1 is shifted by an offset amount.

Abstract: A current detection circuit of the present invention has a switching device 1; an auxiliary switching device 2; an offset voltage source comprising an offset resistor device 7 and a current source circuit 8; a compensation circuit, comprising a differential amplifier 4 and a compensation transistor 5, for adjusting the output current of the auxiliary switching device 2 so that the potential obtained by subtracting the voltage drop across the offset resistor device 7 from the output potential of the switching device 1 is equal to the output potential of the auxiliary switching device 2, being configured that the detection level of the current flowing in the switching device 1 is shifted by an offset amount.

Abstract: An output detection feedback section (5) for controlling the power supply output voltage of a converter unit (4) in response to an error signal Ve has an error amplifier (26) for outputting the error signal Ve, a phase compensation circuit (41), a state detection circuit (42), and a response compensation circuit (43) for setting the voltage of a capacitor (29) of the phase compensation circuit (41) to a predetermined value. When output voltage is switched, the output voltage is fixed at the predetermined value in a DC manner while a transitional response of the error signal (Ve) is accelerated, so that the output voltage is changed at a high speed to a desired value and the overshoot and undershoot are suppressed around the desired value.

Abstract: In a DC-DC converter conforming to the current mode control system, in which the valley value of an inductor current is controlled for output control, a current detection circuit 6 is configured to detect the current flowing from a low-side FET 2 to an inductor 3 using an FET 60, an NPN transistor 61, an NPN transistor 62, a PNP transistor 64, a PNP transistor 65 and a resistor 66, to detect the current flowing from the inductor 3 to the low-side FET 2 using an FET 67, a differential amplifier 68, an FET 69 and the resistor 66, and to output a current detection signal Vc.

Abstract: A step-up converter includes an inductor which receives input voltage Vi at one end, a first FET of the first conduction type which functions as a switch for determining whether or not energy is accumulated in the inductor, a second FET of the second conduction type which rectifies a current output from the other end of the inductor, an output capacitor having an end connected to the source of the second FET, a current detection circuit, and a feedback control circuit. The current detection circuit detects a current flowing through the first N-channel FET to output current detection signal Vc. The feedback control circuit controls the operations of the first N-channel FET and a P-channel FET based on current detection signal Vc.

Abstract: A current detector detects a current flowing through a high-side switch to output a current detection signal. When the current detection signal is lower than an error signal which is generated based on the difference between an output voltage and a reference voltage, a comparator outputs a signal. A timer outputs a signal a predetermined time after the high-side switch is turned ON. When the timer outputs the signal and the comparator outputs the signal, the high-side switch is turned OFF.

Abstract: An output detection feedback section (5) for controlling the power supply output voltage of a converter unit (4) in response to an error signal Ve has an error amplifier (26) for outputting the error signal Ve, a phase compensation circuit (41), a state detection circuit (42), and a response compensation circuit (43) for setting the voltage of a capacitor (29) of the phase compensation circuit (41) to a predetermined value. When output voltage is switched, the output voltage is fixed at the predetermined value in a DC manner while a transitional response of the error signal (Ve) is accelerated, so that the output voltage is changed at a high speed to a desired value and the overshoot and undershoot are suppressed around the desired value.

Abstract: For controlling DC-DC converters conforming to voltage mode control system and current mode control system, in multi-output power supply, first converter section 2 is configured that first detection circuit 31 outputs first control signal, that first oscillation circuit 32 outputs first triangular wave signal and clock signal, and that first pulse-width modulation circuit 33 drives first switch by comparing first control signal with first triangular wave signal. Second converter section 4 is configured that second detection circuit 34 outputs second control signal, that second oscillation circuit 35 outputs second triangular wave signal synchronized with clock signal, that current detection circuit 36 outputs current signal of second inductor, and that second pulse-width modulation circuit 37 turns ON second switch in synchronization with clock signal and turns OFF second switch by calculating or comparing second control signal, the second triangular wave signal and current signal.

Abstract: A DC-DC converter has switching means which generates a continuous switching voltage having a specified period from an input voltage and outputs the generated switching voltage, output voltage generating means which receives the switching voltage at an inductor and generates an output voltage obtained by rectifying and smoothing a voltage generated in the inductor, lamp signal generating means which generates a lamp signal and outputs the generated lamp signal, and control means which performs an arithmetic operation using a current signal relative to a current flowing in the inductor, an error signal relative to the output voltage, and the lamp signal to generate a control signal for controlling the operation of the switching means and outputs the generated control signal to the switching means.

Abstract: A multi-output power supply circuit comprising a switching circuit 10 having a series circuit of a high-side switch 11 and a low-side switch 12, connected in parallel with an input DC power supply 1, and a step-down control circuit 13, and multiple step-up circuits 20 and 30 connected to the output terminal of the switching circuit, wherein each step-up circuit has an inductor connected to the output terminal of the switching circuit, a step-up switch, a step-up rectifier, smoothing means for outputting an output DC voltage, and a step-up control circuit for driving the step-up switch.

Abstract: A DC-DC converter has switching means which generates a continuous switching voltage having a specified period from an input voltage and outputs the generated switching voltage, output voltage generating means which receives the switching voltage at an inductor and generates an output voltage obtained by rectifying and smoothing a voltage generated in the inductor, lamp signal generating means which generates a lamp signal and outputs the generated lamp signal, and control means which performs an arithmetic operation using a current signal relative to a current flowing in the inductor, an error signal relative to the output voltage, and the lamp signal to generate a control signal for controlling the operation of the switching means and outputs the generated control signal to the switching means.

Abstract: For controlling DC-DC converters conforming to voltage mode control system and current mode control system, in multi-output power supply, first converter section 2 is configured that first detection circuit 31 outputs first control signal, that first oscillation circuit 32 outputs first triangular wave signal and clock signal, and that first pulse-width modulation circuit 33 drives first switch by comparing first control signal with first triangular wave signal. Second converter section 4 is configured that second detection circuit 34 outputs second control signal, that second oscillation circuit 35 outputs second triangular wave signal synchronized with clock signal, that current detection circuit 36 outputs current signal of second inductor, and that second pulse-width modulation circuit 37 turns ON second switch in synchronization with clock signal and turns OFF second switch by calculating or comparing second control signal, the second triangular wave signal and current signal.

Abstract: A current detection circuit of the present invention has a switching device 1; an auxiliary switching device 2; an offset voltage source comprising an offset resistor device 7 and a current source circuit 8; a compensation circuit, comprising a differential amplifier 4 and a compensation transistor 5, for adjusting the output current of the auxiliary switching device 2 so that the potential obtained by subtracting the voltage drop across the offset resistor device 7 from the output potential of the auxiliary device 1 is equal to the output potential of the auxiliary switching device 2, being configured that the detection level of the current flowing in the switching device 1 is shifted by an offset amount.