Patent application number | Description | Published |
20090040676 | CIRCUIT FOR DETECTING POWER SUPPLY VOLTAGE DROP - Provided is a circuit for detecting power supply voltage drop having a small circuit scale. An NMOS transistor ( | 02-12-2009 |
20090146499 | POWER SUPPLY SWITCHING CIRCUIT - In a power supply switching circuit, a transistor that switches to a highest voltage is formed of an enhancement type PMOS transistor, and transistors that switch other voltages are each formed of a depletion type NMOS transistor. A signal for controlling a gate of each of the transistors is input through a level shifter. The depletion type NMOS transistor does not operate in a bipolar manner even if a source voltage thereof reaches a power supply voltage VPP | 06-11-2009 |
20090167410 | POWER SUPPLY SWITCHING CIRCUIT - Provided is a power supply switching circuit capable of efficiently supplying a desired voltage among a plurality of voltages to a load. In the case of a P-type semiconductor substrate, N-type MOS transistors are provided between a load and an AC adapter and between the load and a battery, and hence no parasitic diode exists between the load and the AC adapter or the battery, resulting in no current path due to the parasitic diode. Thus, when the AC adapter and the battery are connected to the power supply switching circuit, the N-type MOS transistor is turned off, whereby the current path between the battery and the load is cut off completely and the N-type MOS transistor is turned on. Accordingly, the battery cannot supply a voltage to the load while only the AC adapter can supply a voltage to the load. | 07-02-2009 |
20090184753 | CHARGE PUMP CIRCUIT - Provided is a charge pump circuit capable of shortening a settling time. When a boosted voltage (Vout) becomes high to be equal to or larger than an overshoot voltage, a transistor (T1) is turned on and an output terminal of the charge pump circuit is discharged. Accordingly, it is easy to reduce the boosted voltage (Vout) after an occurrence of an overshoot, and a period of time in which the boosted voltage (Vout) decreases from a voltage after the occurrence of the overshoot to a desired voltage is shortened, leading to a reduction in a settling time. | 07-23-2009 |
20090190407 | SEMICONDUCTOR MEMORY DEVICE - Provided is a semiconductor memory device, which realizes characteristic evaluation even in a case where a threshold voltage is a negative potential by a test method which is similar to a case of a positive potential. The semiconductor memory device includes a plurality of memory cells for storing data. When a test signal is input, the semiconductor memory device changes from a normal mode to a test mode for evaluating characteristics of the plurality of memory cells. The semiconductor memory device also includes: a memory cell selecting portion for selecting a memory cell; a constant voltage portion for generating a reference voltage; a constant current portion for generating a reference current; an X switch voltage switching control circuit for supplying one of an X selection signal and a voltage signal input from an external terminal to a gate of the memory cell; a Y switch portion for supplying the reference current to a drain of the memory cell selected by a Y selection signal; a comparator for detecting whether or not a drain voltage that is a voltage of the drain has exceeded the reference voltage; and a decision level changing portion for adjusting a current value of the reference current and a voltage value of the reference voltage so as to change a decision level of the comparator based on a control signal in the test mode. | 07-30-2009 |
20090195284 | SEMICONDUCTOR DEVICE EQUIPPED WITH A PULL-DOWN CIRCUIT - Provided is a semiconductor device equipped with a pull-down circuit capable of reducing its area. The pull-down circuit is formed of a depletion type NMOS transistor in which a gate thereof is connected to a ground potential, and an enhancement type NMOS transistor in which a gate and a drain thereof are connected to a source of the depletion type NMOS transistor and a source thereof is connected to the ground potential. An overdrive voltage of the depletion type NMOS transistor is reduced by a threshold voltage of the enhancement type NMOS transistor, whereby a size of the depletion type NMOS transistor can be reduced. Accordingly, an area of the pull-down circuit can be reduced. | 08-06-2009 |
20090201006 | CONSTANT CURRENT CIRCUIT - Provided is a constant current circuit capable of supplying a stable constant current. Even when K values of NMOS transistors vary due to manufacturing fluctuations in semiconductor devices, a voltage generated across a resistor is always a threshold voltage difference between the NMOS transistors, and thus hardly varies. Even when the K values of the NMOS transistors vary due to a change in temperature, the voltage generated across the resistor is always the threshold voltage difference between the NMOS transistors, and thus hardly varies. | 08-13-2009 |
20090213665 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - Provided is a nonvolatile semiconductor memory device which reads out a memory cell at high speed. A minute current source ( | 08-27-2009 |
20100188124 | POWER-ON RESET CIRCUIT - Provided is a power-on reset circuit suitable for a semiconductor device that operates at a low supply voltage. When a supply voltage (VDD) becomes higher than a first output circuit reversal threshold voltage (Vz) after a reset signal is output, a first control circuit ( | 07-29-2010 |
20100188137 | BOOSTING CIRCUIT - Provided is a boosting circuit having a small circuit scale. When a node (Vg) is reset by a reset transistor (M | 07-29-2010 |
20100213932 | MAGNETIC SENSOR CIRCUIT - Provided is a magnetic sensor circuit capable of a low-voltage operation, which comprises a Hall element and a magnetic offset cancellation circuit for the Hall element. In the magnetic sensor circuit using the Hall element, at the time of turning on transmission gates for switching connections between input terminals of an amplifier circuit in the magnetic offset cancellation circuit and electrodes of the Hall element in order to cancel a magnetic offset of the Hall element, gates of N-channel transistors in the transmission gates are set at voltages higher than a power supply voltage by a drive circuit. | 08-26-2010 |
20100258706 | PHOTODETECTOR CIRCUIT AND ELECTRONIC DEVICE - Provided is a photodetector circuit having significantly low current consumption. The photodetector circuit includes two opposing P-channel metal oxide semiconductor (MOS) transistors each including a gate connected to a drain of the opposing P-channel MOS transistor. The drain of one of the P-channel MOS transistors is discharged with an ON-state current of an N-channel MOS transistor which is turned ON with a voltage generated in a photoelectric element. The drain of the other of the P-channel MOS transistors is discharged with an ON-state current of a depletion type N-channel MOS transistor including a gate to which a voltage of a reference power supply terminal is input, and a source to which the voltage generated in the photoelectric element is input. | 10-14-2010 |
20110001513 | CMOS INPUT BUFFER CIRCUIT - Provided is a complementary metal oxide semiconductor (CMOS) input buffer circuit that is capable of lower voltage operation with lower current consumption. The CMOS input buffer circuit includes: a depletion type NMOS transistor including a drain connected to a power supply terminal (VDD), and a gate connected to an output terminal; a PMOS transistor including a source connected to a source of the depletion type NMOS transistor, a drain connected to the output terminal, and a gate connected to an input terminal; and an NMOS transistor including a source connected to a reference terminal (GND), a gate connected to the input terminal, and a drain connected to the output terminal. | 01-06-2011 |
20110109364 | INPUT CIRCUIT - Provided is an input circuit having hysteresis characteristics that is capable of operating in a wide range of power supply voltage conditions while suppressing power supply voltage dependence of a hysteresis voltage and a response speed. The input circuit is provided with: a circuit for obtaining a small hysteresis voltage under the condition of low power supply voltage (formed of PMOS transistors ( | 05-12-2011 |
20110193781 | MOUSE DEVICE - Provided is a convenient mouse device having low power consumption. The mouse device has a configuration in which an optical sensor for light shielding detection is provided in a region where a hand blocks light when the hand handles the mouse device so that the mouse device may perform a normal operation when the optical sensor for light shielding detection is shielded from light, and may perform a low consumption operation when the optical sensor for light shielding detection is not shielded from light. | 08-11-2011 |
20110234302 | PROXIMITY SENSOR USING PHOTOSENSOR - Provided is a proximity sensor using a photosensor, which is easy to use and reduced in power consumption. In the proximity sensor, a first photosensor is used to detect a change in amount of ambient light entering the first photosensor, which is caused when a finger is coming close thereto, and a detection signal is output based on a result of the detection. The photosensor includes, for example, one or a plurality of PN junction elements connected in parallel. | 09-29-2011 |
20110272749 | LIGHT RECEIVING CIRCUIT - Provided is a light receiving circuit for detecting a change in amount of light, in which an input circuit at a subsequent stage is compact and inexpensive and current consumption is low. The light receiving circuit includes: a photoelectric conversion element for supplying a current corresponding to an amount of incident light; an N-channel MOS transistor including a drain supplied with the current from the photoelectric conversion element; and a control circuit for controlling a gate voltage of the NMOS transistor via a low pass filter so that a drain voltage of the N-channel MOS transistor becomes a desired voltage. The control circuit outputs a control state output signal, which is a GND terminal voltage when a delay amount of control on the gate voltage of the NMOS transistor performed via the low pass filter is less than a desired delay amount, and is the drain voltage of the NMOS transistor when the delay amount of control on the gate voltage of the NMOS transistor performed via the low pass filter is the desired delay amount or more. The light receiving circuit outputs the control state output signal as an output signal. | 11-10-2011 |
20110304376 | SEMICONDUCTOR INTEGRATED CIRCUIT INCLUDING VARIABLE RESISTOR CIRCUIT - Provided is a semiconductor integrated circuit including a variable resistor circuit of the small layout area, which is free from an error in resistance caused by ON-state resistances of switch elements for trimming, and is also free from power supply voltage dependence and temperature dependence. The semiconductor integrated circuit including a variable resistor circuit includes: a resistor circuit including a plurality of series-connected resistors; a selection circuit including a plurality of switch elements for selecting a connected number of the plurality of series-connected resistors; and a control circuit for controlling ON-state resistances of the plurality of switch elements. The control circuit controls the ON-state resistances of the plurality of switch elements so as to obtain a predetermined ratio to a resistance of the plurality of series-connected resistors of the resistor circuit. | 12-15-2011 |
20120242317 | REFERENCE VOLTAGE CIRCUIT - Provided is a reference voltage circuit with improved temperature characteristics. A current based on a current flowing through a first depletion transistor whose gate and source are connected to each other is caused to flow through a third depletion transistor having the same threshold, to thereby generate a voltage between a gate and a source of the third depletion transistor. A current based on a current flowing through a second depletion transistor whose gate and source are connected to each other is caused to flow through a fourth depletion transistor having the same threshold, to thereby generate a voltage between a gate and a source of the fourth depletion transistor. A reference voltage is generated based on a difference voltage of the two voltages, to thereby obtain a reference voltage having less voltage fluctuations with respect to a temperature change. | 09-27-2012 |
20130241525 | REFERENCE VOLTAGE CIRCUIT - A constant current flowing through a first depletion transistor whose gate and source are connected to each other is caused to flow through a second depletion transistor having the same threshold as the first depletion transistor, to thereby generate a first voltage between a gate and a source of the second depletion transistor. The constant current of the first depletion transistor and a constant current flowing through a third depletion transistor whose gate and source are connected to each other are caused to flow through a fourth depletion transistor. A threshold of the fourth depletion transistor is the same as that of the third depletion transistor but different from that of the first depletion transistor, and hence a second voltage is generated between a gate and a source of the fourth depletion transistor. A reference voltage is generated based on a voltage difference between the first and second voltages. | 09-19-2013 |
20130251372 | DEVICE IDENTIFICATION APPARATUS AND REMOTE CONTROL SYSTEM - Each device identification apparatus includes a circuit for generating a delay time and transmits a device identification code signal at a different delay time in response to a device selecting signal from a remote controller, thereby making it possible to prevent interference. Further, an infrared light amount detecting circuit is provided in a device identification apparatus or a remote controller, and an electronic device to which a device identification apparatus having a higher intensity of infrared is attached is displayed on the remote controller so that the electronic device is easily selected. | 09-26-2013 |
20130251373 | DEVICE IDENTIFICATION APPARATUS AND REMOTE CONTROL SYSTEM - The device identification apparatus includes: a remote controller signal detecting section for detecting an optical signal from a remote controller; a receiving section for receiving the optical signal from the remote controller; a signal decryption section for decrypting the optical signal received by the receiving section; and a transmitting section for transmitting a device identification signal when the optical signal is a device selecting signal, and configured such that operations of the receiving section, the signal decryption section, and the transmitting section are started in response to a detecting signal of the remote controller signal detecting section, thereby realizing a device identification apparatus in which power consumption during standby is minimized. | 09-26-2013 |
20130293202 | ELECTRONIC DEVICE - Provided is an electronic device capable of supplying desired electric power to a load so as to operate the load even in a case where charged power is minute and a voltage increase rate of a capacitor, which increases by charge, is low. The electronic device includes: a power source which has supply power less than consumption power of the load; a capacitor to be charged with the supply power; and a charge/discharge control circuit which controls charging of the capacitor and consumption of charged power of the capacitor by the load, and the charge/discharge control circuit includes: a first node to which the supply power of the power source is supplied; and a circuit which charges the capacitor with the supply power from the first node. | 11-07-2013 |
20140253068 | VOLTAGE REGULATOR - Provided is a voltage regulator capable of controlling an output voltage to a predetermined voltage quickly after an overshoot occurs in the output voltage. The voltage regulator includes: an overshoot detection circuit configured to detect a voltage that is based on an output voltage of the voltage regulator, and output a current corresponding to an overshoot amount of the output voltage; and an I-V converter circuit configured to control a current flowing through an output transistor based on a current controlled by an output of an error amplifier and a current flowing from the overshoot detection circuit. | 09-11-2014 |
20140253069 | VOLTAGE REGULATOR - Provided is a voltage regulator capable of controlling an output voltage to a predetermined voltage quickly after an undershoot occurs in the output voltage. The voltage regulator includes: an undershoot detection circuit configured to detect a voltage that is based on an output voltage of the voltage regulator, and output a current corresponding to an undershoot amount of the output voltage; and an I-V converter circuit configured to control a current flowing through an output transistor based on a current controlled by an output of an error amplifier and a current flowing from the undershoot detection circuit. | 09-11-2014 |
20140253076 | VOLTAGE REGULATOR - Provided is a voltage regulator capable of, when an overshoot or undershoot occurs in an output voltage, improving the overshoot or undershoot in a wide temperature range and reducing a delay in detection of the overshoot or undershoot. The voltage regulator includes: an error amplifier; an output transistor; and a first transistor including a gate for inputting a reference voltage and a source for inputting an output voltage. The first transistor is configured to cause a current to flow when the output voltage becomes an irregular voltage, and a current of the output transistor is controlled based on the current flowing through the first transistor. | 09-11-2014 |
20140266313 | LIGHT RECEIVING CIRCUIT - The light receiving circuit includes: a photoelectric conversion element for causing a current corresponding to an amount of incident light to flow to a node; a voltage detection circuit for outputting a detection signal when a voltage of the node becomes equal to or higher than a first voltage; a reset circuit for causing, when the detection signal of the voltage detection circuit is input, the current of the photoelectric conversion element to flow to a GND terminal so that the voltage of the node becomes a second voltage lower than the first voltage, and for holding this state when the detection signal is no longer input; and a voltage increase detection circuit for detecting a fluctuation in the voltage of the node and outputting a detection result. | 09-18-2014 |
20140266368 | LIGHT RECEIVING CIRCUIT - The light receiving circuit includes: a photoelectric conversion element for causing a current corresponding to an amount of incident light to flow; a MOS transistor including a source connected to the photoelectric conversion element and a drain connected to a node, for causing the current of the photoelectric conversion element to flow to the node while maintaining a voltage of the source to a first voltage; a reset circuit for causing a current to flow from the node to a GND terminal so that a voltage of the node becomes a second voltage lower than the first voltage; a control circuit for outputting a reset signal to the reset circuit; and a voltage increase detection circuit for detecting a fluctuation in the voltage of the node and outputting a detection result. | 09-18-2014 |
20150060671 | INFRARED DETECTOR - Provide is an infrared detector that has a simple configuration, has a high amplification factor, and is configured to operate at low voltage. An NMOS transistor at an output stage of a pyroelectric infrared detection element serves as a common source amplifier circuit in which a source is connected to GND via a resistor and a capacitor that are connected in parallel. | 03-05-2015 |