Rohm Co., Ltd.

Motohiro Ando

Yuji Ishimatsu

Akio Sasabe

Kenji Hama

Provided is a semiconductor device that has a configuration provided with: a driving unit for driving an upper switching element and a lower switching element according to a control signal for controlling the driving of the upper switching element and the lower switching element, which are connected in series to constitute a bridge circuit; an insulating unit having an insulating transformer; and a package for sealing at least a part of the insulating unit and the driving unit. The insulating unit transmits a signal corresponding to the control signal to the driving unit side while insulating the signal.

Semiconductor device

A power semiconductor drive circuit includes a parallel circuit connected to a gate of a power semiconductor element and constituted by two transistors for setting gate resistance of the power semiconductor element; a gate voltage monitoring circuit connected to the gate of the power semiconductor element and the parallel circuit, wherein a monitoring voltage is set in the gate voltage monitoring circuit to monitor a gate voltage of the power semiconductor element; a signal delay circuit to delay an output signal of the gate voltage monitoring circuit; and a gate control circuit to change the magnitude of combined resistance of the parallel circuit based on an output signal output from the signal delay circuit.

Power semiconductor drive circuit, power semiconductor circuit, and power module circuit device

Semiconductor device with upper and lower switching devices and isolation transformer

The load drive device of the present invention comprises a load drive unit for switching on/off output current that flows to an inductive load; and an overcurrent protection circuit for detecting whether the output current is in an overcurrent state, wherein the load drive unit has an output transistor connected to one end of the inductive load; and a pre-driver for generating a control signal of the output transistor in accordance with an input signal, and the pre-driver has a first drive unit for switching on/off the output transistor during normal operation; and a second drive unit for switching off the output transistor more slowly than the first drive unit during overcurrent protection operation.

Load drive device

A ground protection circuit () includes: a sensing resistor (R), disposed on a path which a charging current (IB) of a bootstrap circuit (D, C) flows through; a comparator (), for comparing a voltage (&#x394;V) between two ends of the sensing resistor (R) and a specific threshold voltage (Vth) to generate a ground protection signal (S); and a logic gate (), for enabling the ground protection signal (S) to be invalid in a normal charging operation of the bootstrap circuit.

Ground protection circuit and switch driving device using the same

An abnormality detection circuit monitors the sink current Irnf of a H-bridge circuit and determines the presence of an abnormal state if the sink current is not detected for a predetermined time. The abnormality detection circuit includes a clock pulse generator, a counter and a NMOS transistor. The abnormality detection circuit includes a clock pulse generator arranged to generate a clock pulse of a predetermined frequency, and a counter arranged so that a count value is incremented every time the clock pulse is provided to the counter and arranged so that the count value is reset when the sink current is detected. The counter generates a first abnormality detection signal that changes from a normal logic level to an abnormal logic level when the count value reaches a predetermined value without being reset.

Abnormality detection circuit, load driving device, and electrical apparatus

A motor drive device in which the torque vector of the motor is controlled so that the correlation between the number of pulses of a clock signal and the phase of the torque vector of the motor is held in common for multiple excitation methods. The excitation method having the greatest number of steps is used as a reference, and the torque vector of the motor is maintained in the same phase as before switching when the excitation method is switched. The torque vector is in the closest phase in the rotation direction of the motor when there is no phase that is the same as the phase prior to switching.

Motor drive device and electronic device that uses the same

A motor driver that supplies a drive current to a stepping motor includes a decay rate controller configured to mix a first decay rate and a second decay rate smaller than the first decay rate with each other, and set a plurality of mix decay rates, a control logic circuit configured to create magnetization patterns for attenuating the drive current at the mix decay rates, and a drive current output circuit configured to output the drive current to the stepping motor in accordance with the magnetization patterns.

Motor driver supplying drive current while adjusting decay rate thereof

A drive circuit drives a motor in a mode selected from first and second modes. A drive unit operates in response to a control signal received from a signal generation unit to control how the motor should rotate. The control signal is applied to drive the motor in the first mode. The signal generation unit receives a select signal indicating one of the first and second modes. When the select signal indicates the first mode, the signal generation unit outputs an input signal as the control signal. When the select signal indicates the second mode, the signal generation unit generates the control signal in accordance with the input signal. A motor drive circuit capable of driving a motor regardless of a difference between input modes in type, and electronics equipped with, can thus be obtained.

Growing community of inventors

Kyoto, Japan

Motohiro Ando