Abstract: A switch circuit is configured of a first semiconductor element and a second semiconductor element connected in series, and receives a DC voltage of 100 V or more. The drive circuit causes the first semiconductor element or the second semiconductor element to perform a switching operation. The isolated power supply circuit converts a predetermined power supply voltage into an isolated first power supply voltage, and outputs the first power supply voltage to the drive circuit. The isolation signal converter converts a first signal of 6 MHz or more into an isolated first drive signal, and outputs the first drive signal to the drive circuit. The single substrate mounts the isolated power supply circuit and the isolation signal converter. Both the first semiconductor element and the second semiconductor element are wide bandgap semiconductor elements.

Abstract: A driver circuit which is supplied with a positive power supply voltage, a negative power supply voltage, and an input signal, and drives a switching element including a control terminal according to the input signal includes: a first output terminal connected to the control terminal via a first impedance circuit, and outputs the positive power supply voltage or the negative power supply voltage according to the input signal, to charge the control terminal and put the switching element into an ON state; a negative power supply terminal supplied with the negative power supply voltage; a negative voltage switch having a first end connected to the negative power supply terminal; a third output terminal connected to a second end of the negative voltage switch and to the control terminal via a second impedance circuit; and a first discharge switch disposed between the negative power supply terminal and the first output terminal.

Abstract: A driver circuit which is supplied with a positive power supply voltage, a negative power supply voltage, and an input signal, and drives a switching element including a control terminal according to the input signal includes: a first output terminal connected to the control terminal via a first impedance circuit, and outputs the positive power supply voltage or the negative power supply voltage according to the input signal, to charge the control terminal and put the switching element into an ON state; a negative power supply terminal supplied with the negative power supply voltage; a negative voltage switch having a first end connected to the negative power supply terminal; a third output terminal connected to a second end of the negative voltage switch and to the control terminal via a second impedance circuit; and a first discharge switch disposed between the negative power supply terminal and the first output terminal.

Abstract: A DC-DC converter system that can switch between BOOST and BUCK operation is used in a power failure prevention system. The DC-DC converter operates in BOOST mode at startup. It charges a storage capacitor via an inductor having its peak current controlled, together with a soft start ramp to limit the power supply in-rush current. During power failure, if the storage capacitor is charged above a pre-determined threshold and the input power supply discharges below a programmable threshold, the DC-DC converter switches from BOOST to BUCK mode, detectable through an internal power detection circuit; its output may also control an external/internal power switch that isolate the input main supply from the power bus. The BUCK mode converter will then dump the charges from the storage capacitor back to the power bus. The BOOST to BUCK mode seamless switchover is achieved through an analog/digital multiplexer that simplify the circuit implementation.

Abstract: LED drivers specially directed to LED matrix driver's ghost image prevention is disclosed. The LED driver receives an external input and decodes the input to produce a time multiplex timing on turning on an LED array. The LED driver inserts a dead time to the outputs and during this time the ghost image prevention circuit discharges the output stray capacitances to a predetermined level.

Abstract: LED drivers specially directed to LED matrix driver's ghost image prevention is disclosed. The LED driver receives an external input and decodes the input to produce a time multiplex timing on turning on an LED array. The LED driver inserts a dead time to the outputs and during this time the ghost image prevention circuit discharges the output stray capacitances to a predetermined level.

Abstract: A power supply apparatus having a soft start function that enables a startup without any overshoot within an appropriate startup time regardless of whether the load is heavy or light. Even when output direct current voltage Vo has not yet risen upon startup, switch circuit (4) is turned ON within a count time of timer (7), and clamping circuit (5) clamps error signal (Ve) of error amplifier (2), so that an excessive signal is prevented from entering PWM circuit (6), and electric power supplied to load (13) is controlled. Consequently, supply power as the power supply apparatus is limited, and any inrush current can be prevented from being generated. By controlling the count time of timer (7) when this error signal is clamped, it is possible to realize a startup within an appropriate startup time without any overshoot.

Abstract: An interface detecting circuit and interface detecting method are provided, whereby operations can be carried out depending on peripheral devices connected to USB terminals, and whereby the system can be simplified and software load can be reduced. A pull-down resistor is connected to an ID terminal of a Mini-A receptacle of a peripheral device, the voltage generated by the pull-down resistor, which is pulled down by the ID terminal of the Mini-A receptacle of the peripheral device, and a pull-up resistor, which is pulled up by the ID terminal of a Mini-B receptacle of a device, is detected in an analog fashion, using a detecting section comprised of comparators, and, via a logic section, a logic output is subjected to noise cancellation in a filter section and is memorized in a register section. The operations of other devices are determined according to the states memorized in the register section.

Abstract: An interface detecting circuit and interface detecting method are provided, whereby operations can be carried out depending on peripheral devices connected to USB terminals, and whereby the system can be simplified and software load can be reduced. A pull-down resistor is connected to an ID terminal of a Mini-A receptacle of a peripheral device, the voltage generated by the pull-down resistor, which is pulled down by the ID terminal of the Mini-A receptacle of the peripheral device, and a pull-up resistor, which is pulled up by the ID terminal of a Mini-B receptacle of a device, is detected in an analog fashion, using a detecting section comprised of comparators, and, via a logic section, a logic output is subjected to noise cancellation in a filter section and is memorized in a register section. The operations of other devices are determined according to the states memorized in the register section.

Abstract: A power supply apparatus having a soft start function that enables a startup without any overshoot within an appropriate startup time regardless of whether the load is heavy or light. Even when output direct current voltage Vo has not yet risen upon startup, switch circuit 4 is turned ON within a count time of timer 7, and clamping circuit 5 clamps error signal Ve of error amplifier 2, so that an excessive signal is prevented from entering PWM circuit 6, and electric power supplied to load 13 is controlled. Consequently, supply power as the power supply apparatus is limited, and any inrush current can be prevented from being generated. By controlling the count time of timer 7 when this error signal is clamped, it is possible to realize a startup within an appropriate startup time without any overshoot.