Abstract: In a half bridge circuit according to one aspect of the present disclosure, when a voltage between a first terminal and a third terminal or a voltage between the first terminal and the second terminal is greater than or equal to a threshold voltage, a current is passed from the second terminal to the third terminal or from the third terminal to the second terminal according to a polarity of the voltage between the second terminal and the third terminal. When the current is passed from the third terminal to the second terminal, the voltage between the second terminal and the third terminal changes with respect to the voltage applied between the first terminal and the third terminal within a range where the voltage between the first terminal and the third terminal is less than or equal to the threshold voltage.

Abstract: In a half bridge circuit according to one aspect of the present disclosure, when a voltage between a first terminal and a third terminal or a voltage between the first terminal and the second terminal is greater than or equal to a threshold voltage, a current is passed from the second terminal to the third terminal or from the third terminal to the second terminal according to a polarity of the voltage between the second terminal and the third terminal. When the current is passed from the third terminal to the second terminal, the voltage between the second terminal and the third terminal changes with respect to the voltage applied between the first terminal and the third terminal within a range where the voltage between the first terminal and the third terminal is less than or equal to the threshold voltage.

Abstract: A matrix converter control apparatus includes three AC switches each including a first and a second switching elements connected in series. The first and the second switching devices each: have a first terminal, a second terminal, and a gate terminal; pass a current between the first terminal and the second terminal when a first voltage which is a voltage of the gate terminal with reference to a voltage of the first terminal is higher than a threshold voltage; interrupt a current flowing from the second terminal to the first terminal when the first voltage is lower than the threshold voltage; and pass a current from the first terminal to the second terminal when the first voltage is lower than the threshold voltage and the voltage of the gate terminal is higher than the threshold voltage with reference to a voltage of the second terminal.

Abstract: A buck-boost AC/DC converter includes a first switching element group that performs full-wave rectification of an AC signal thereby generating a full-wave rectified signal and performs a buck operation, a second switching element group for performing a boost operation, a reactor, and a control unit that causes the first switching element group or the second switching element group to selectively perform the buck operation or the boost operation based on PWM operation, to maintain a DC voltage at a constant value. The switching elements included in the first and second switching element groups possess FET characteristics, inverse FET characteristics and inverse conductive characteristics. The control unit is further configured to switch a gate-source voltage to be supplied to the switching elements included in the first switching element group according to a polarity of the AC signal, thereby causing the first switching element group to perform full-wave rectification.

Abstract: A matrix converter control apparatus includes three AC switches each including a first and a second switching elements connected in series. The first and the second switching devices each: have a first terminal, a second terminal, and a gate terminal; pass a current between the first terminal and the second terminal when a first voltage which is a voltage of the gate terminal with reference to a voltage of the first terminal is higher than a threshold voltage; interrupt a current flowing from the second terminal to the first terminal when the first voltage is lower than the threshold voltage; and pass a current from the first terminal to the second terminal when the first voltage is lower than the threshold voltage and the voltage of the gate terminal is higher than the threshold voltage with reference to a voltage of the second terminal.

Abstract: When a drive signal that is a PWM input signal is small (when the drive duty component of the PWM drive signal is small), shoot-through (through state) between the upper transistor and lower transistor can occur when there is variation in the drive circuit or transistors. An upper switching device and lower switching device control current supply to a load, and an upper drive circuit and lower drive circuit respectively drive the upper switching device and lower switching device.

Abstract: In order to provide a switching device driving unit that, even in a case where a threshold voltage of a switching device is varied, can suppress variations in switching speed, and prevent a power loss caused by an unnecessary gate current in a constant ON operation state of the switching device, so that a desired slew rate can be easily set, a control current source circuit sets to different values based on a first input driving signal, in a driving current to be source-outputted to a gate or a base of the switching device, a current in a stage of an initial ON operation of a switching operation of the switching device and a current in a stage after completion of the switching operation.

Abstract: It is an object of the present invention to provide a driving circuit which is adapted, for a semiconductor device which exhibits a diode characteristic of flowing an abrupt current if the gate-source voltage therein exceeds a predetermined voltage, to have the functions of reducing electric-power consumption in high-load state, reducing the loss in the driving circuit in low-load states, preventing excessive voltages, excessive currents and excessive electric-power consumption, and reducing the loss in the semiconductor device.

Abstract: An output circuit includes: an NMOS transistor of an output buffer, a transistor ON drive circuit configured to turn on the transistor; a switchable current source configured to turn off the transistor; and a drive control circuit configured to control the transistor ON drive circuit and the switchable current source. The electric charge at the gate terminal of the NMOS transistor of the output buffer is pulled out with the current of the switchable current source at a fixed current value even when the gate voltage of the transistor varies in a range of variations of the threshold voltage Vth of the transistor.

Abstract: A motor driving device includes a brake mode control section for starting, when a brake instruction for a motor, braking of the motor in a reverse brake mode and then switching the reverse brake mode to a short brake mode; a cycle start detection section for receiving a rotation signal and detecting a start of a cycle of the rotation signal for each cycle; and a counter for performing, when the start of the cycle of the rotation signal is detected by the cycle start detection section, a count operation from an initial value. In the motor driving device, the brake mode control section detects that a value of the counter exceeds a threshold and performs switching from the reverse brake mode to the short brake mode with a delay from the detection.

Abstract: There is provided a motor driving apparatus in which variations in individual circuit constants have a small effect even when a drive current is small. An error amplifier circuit amplifies a difference between a current detection signal showing a current value of a drive current that flows in the motor and a drive command signal controlling the drive current and converts an amplified difference into a current to output the current as an error amplifier current signal. A D/A conversion circuit generates a sinusoidal signal from the error amplifier current signal based on a digital signal sequence outputted from a rotational position detecting unit. It is preferable that a transfer coefficient of the error amplifier circuit is inversely proportional to the resistance value of the D/A conversion circuit.

Abstract: Optical disc drives designed for reduced power consumption switch the supply voltage in three stages between first, second, and third power supplies. The reduction in power consumption that is possible in the focusing and tracking drive circuits with three stage switching control is limited. This drive apparatus enables further reductions in power consumption. A drive output tracking signal is generated according to the drive conditions of the focusing or tracking drive circuit. The drive output tracking signal is applied to the drive circuit power supply, and the power supply is controlled according to the drive output tracking signal. A power supply change detector detects sudden changes in the drive output tracking signal, and inputs the detection signal to the DSP controlling the entire system. The DSP determines whether to improve the power supply response by comparison with predetermined conditions, and returns the result to the power supply.

Abstract: A motor driving device includes a brake mode control section for starting, when a brake instruction for a motor, braking of the motor in a reverse brake mode and then switching the reverse brake mode to a short brake mode; a cycle start detection section for receiving a rotation signal and detecting a start of a cycle of the rotation signal for each cycle; and a counter for performing, when the start of the cycle of the rotation signal is detected by the cycle start detection section, a count operation from an initial value. In the motor driving device, the brake mode control section detects that a value of the counter exceeds a threshold and performs switching from the reverse brake mode to the short brake mode with a delay from the detection.

Abstract: There is provided a motor driving apparatus in which variations in individual circuit constants have a small effect even when a drive current is small. An error amplifier circuit amplifies a difference between a current detection signal showing a current value of a drive current that flows in the motor and a drive command signal controlling the drive current and converts an amplified difference into a current to output the current as an error amplifier current signal. A D/A conversion circuit generates a sinusoidal signal from the error amplifier current signal based on a digital signal sequence outputted from a rotational position detecting unit. It is preferable that a transfer coefficient of the error amplifier circuit is inversely proportional to the resistance value of the D/A conversion circuit.

Abstract: Optical disc drives designed for reduced power consumption switch the supply voltage in three stages between first, second, and third power supplies. The reduction in power consumption that is possible in the focusing and tracking drive circuits with three stage switching control is limited. This drive apparatus enables further reductions in power consumption. A drive output tracking signal is generated according to the drive conditions of the focusing or tracking drive circuit. The drive output tracking signal is applied to the drive circuit power supply, and the power supply is controlled according to the drive output tracking signal. A power supply change detector detects sudden changes in the drive output tracking signal, and inputs the detection signal to the DSP controlling the entire system. The DSP determines whether to improve the power supply response by comparison with predetermined conditions, and returns the result to the power supply.