Patent application number | Description | Published |
20100237818 | DRIVING CIRCUIT FOR BRUSHLESS MOTOR USING HALL ELEMENT - A driving circuit feeds driving current to a coil in a brushless motor, and feeds bias current to a Hall element that senses the rotational position of the motor. The driving current and bias current are supplied from the same power supply, but the bias current passes through a load element that reduces power dissipation by the Hall bias circuit by causing some of the power to be dissipated by the load element instead. The Hall bias circuit can therefore be combined with the other driving circuitry into a single integrated circuit, even if the brushless motor is driven at a comparatively high voltage. | 09-23-2010 |
20100237897 | OVERCURRENT DETECTING CIRCUIT AND POWER SUPPLY DEVICE - An overcurrent detecting circuit includes a comparison transistor, a constant current source circuit, and a comparison circuit. The comparison transistor includes a gate and a drain respectively connected to a gate and a drain of a main transistor provided in a power circuit. The comparison transistor is used for comparison with the main transistor when a voltage higher than a power supply voltage is applied to the gate of the main transistor and the gate of the comparison transistor during the operation of the power circuit. The constant current source circuit generates a constant current and supplies the constant current to the comparison transistor. The comparison circuit compares a source voltage of the comparison transistor with a source voltage of the main transistor and outputs a voltage indicating the comparison result. | 09-23-2010 |
20100237898 | OVERCURRENT DETECTING CIRCUIT AND POWER SUPPLY DEVICE - An overcurrent detecting circuit includes a comparison transistor, a constant current source circuit, a subtraction circuit, and a comparison circuit. The comparison transistor is used for comparison with a main transistor provided in the power circuit. The constant current source circuit supplies a constant current to the comparison transistor. The subtraction circuit subtracts a voltage corresponding to a power supply voltage from a voltage between a drain and a source of the comparison transistor and outputs a voltage indicating the subtraction result. The comparison circuit compares the voltage output from the subtraction circuit with a voltage corresponding to a source voltage of the main transistor and outputs a voltage indicating the comparison result. | 09-23-2010 |
Patent application number | Description | Published |
20090153122 | DROPPER-TYPE REGULATOR - A dropper-type regulator capable of providing a soft start function using a simple circuit configuration. An exemplary regulator includes a first FET having a relatively high current driving capability and a second FET having a relatively low current driving capability are provided in parallel between an input terminal and an output terminal. For a predetermined time immediately after power activation, only the second FET is driven, thereby preventing a large rush current. A switch circuit connected to the gate of the first FET is operated after the predetermined period of time, thereby supplying a driving voltage to the gate of the first FET. | 06-18-2009 |
20090153200 | LOAD DRIVE CIRCUIT - A load drive circuit which can operate at high speed with low consumption current while performing the gate-to-source over voltage protection for its load driving field-effect transistor. A Zener function device is connected between the gate and the source of the load driving field-effect transistor, and an on/off-switch circuit to supply either on-potential or off-potential to the gate of the field effect transistor is provided. The current flowing through the Zener function device when the load driving field-effect transistor is conductive is limited by the on/off-switch circuit. | 06-18-2009 |
20090160416 | DC-DC CONVERTER - A DC-DC converter generates an optimal slope compensation voltage in response to input and output voltages, thus capable of maintaining its operational stability even when a dynamic range of the output voltage is widen. The DC-DC converter compares an error voltage corresponding to a difference between a feedback voltage of the output voltage and a reference voltage with a ramp signal whose voltage level corresponds to a current detection signal, so as to configure an off-timing of an output transistor. A slope of the ramp signal is configured so that the ramp signal is proportional to a difference between the output voltage and the input voltage. A slope compensation circuit for generating the ramp signal includes an adding circuit for generating a slope controlling electric current corresponding to a voltage in which a voltage corresponding to the input voltage is subtracted from a voltage corresponding to the output voltage, and a capacitor electrically charged with the slope controlling current. | 06-25-2009 |
20090160418 | DC-DC CONVERTER - A DC-DC converter includes a reference voltage generation circuit. The reference voltage generation circuit generates a reference voltage for determination of the pulse width of a drive signal to be supplied to a switching circuit. The reference voltage generation circuit includes a current sensing circuit. The current sensing circuit has a first MOS transistor, a second MOS transistor, a resistive element and an amplifier circuit. | 06-25-2009 |
20090184603 | DRIVE CIRCUIT - A drive circuit includes a plurality of output drive terminals and a plurality of push-pull circuit stages. Each of the push-pull circuit stages includes a pair of complementary transistors having a common terminal connected to a respective output drive terminal. The drive circuit further includes a plurality of first transistors connected in series with at least one of the pair of complementary transistors of the push-pull circuit stages, respectively, and a common second transistor. The common second transistor is connected with each of the plurality of first transistors to form a current mirror circuit. The drive circuit further includes a mirror current setting circuit for setting a mirror current flowing through the common transistor | 07-23-2009 |