Abstract: A pattern of grooves or holes is formed in metallic electrodes disposed in upper and lower sides with respect to a vibration member in a capacitance type dynamic quantity sensor. As a result, even when an electrode made of a single electrically conductive material such as Al is used, it is possible to avoid the generation of hillocks on the surface of the electrode, and film-peeling risk of the electrode can be reduced. In addition, the manufacturing cost can also be reduced.

Abstract: A method of manufacturing a mirror having high verticality and less surface roughness, comprising forming a mask material to the surface of a silicon substrate, applying anisotropic dry etching and anisotropic wet etching, thereby anisotropically dry etching the surface substantially parallel with the crystal face in perpendicular to the surface of the substrate and then forming a reflection surface by the anisotropic wet etching step.

Abstract: A smart battery pack having an inexpensive, high-performance N-channel MOS transistor is provided. A level shift is conducted in communications between a remaining battery power detecting circuit of the smart battery pack and an electronic device such that the shifted level matches the signal level of the electronic device.

Abstract: In order to improve drive performance of a voltage regulator (on resistance of an output transistor) while suppressing increases in surface area resistance of an output transistor is reduced by changing the threshold voltage of the output transistor by controlling the back-gate voltages of output transistors of a voltage regulators.

Abstract: In order to improve drive performance of a voltage regulator (on resistance of an output transistor) while suppressing increases in surface area resistance of an output transistor is reduced by changing the threshold voltage of the output transistor by controlling the back-gate voltages of output transistors of a voltage regulators.

Abstract: In order to improve drive performance of a voltage regulator (on resistance of an output transistor) while suppressing increases in surface area resistance of an output transistor is reduced by changing the threshold voltage of the output transistor by controlling the back-gate voltages of output transistors of a voltage regulators.

Abstract: A voltage detecting circuit controls the current consumption of the circuit so as to detect the voltage at a high speed with suppressing the consumption of a battery.

Abstract: An LED drive circuit is provided, which is designed to reduce power consumption. The LED drive circuit cause at least one of a plurality of LEDs at certain time intervals.

Abstract: In accordance with the present invention, a system for measuring the transmission characteristic of an xDSL system that implements high-speed data communication over existing copper wires connecting an office and a subscriber includes a pulling device included in the outside line of an xDSL circuit, which is installed in an office, for pulling a subscriber line. A noise level measuring circuit measures the level of cross-talk noise on the subscriber line. A decision circuit determines, based on the level of cross-talk noise measured, whether or not the subscriber line is usable.

Abstract: When an output impedance of an input power supply for a switching regulator is high, damages caused by a large current are suppressed which are given to switch elements employed in a power supply circuit and the switching regulator. In a step-up type switching regulator control circuit comprising at least an error amplifying circuit and a drive circuit of a switch element and producing an output voltage higher than an input voltage, the error amplifying circuit is operated by the input voltage; the drive circuit of the switch element is operated by the output voltage; the step-up type switching regulator control circuit is further comprised of a voltage detecting circuit operated by the output voltage; the voltage detecting circuit detects the input voltage, and when the input voltage is decreased lower than an arbitrary voltage, the voltage detecting circuit causes the drive circuit of the switch element to produce such a signal capable of firmly turning OFF the switch element.

Abstract: In order to improve drive performance of a voltage regulator (on resistance of an output transistor) while suppressing increases in surface area resistance of an output transistor is reduced by changing the threshold voltage of the output transistor by controlling the back-gate voltages of output transistors of a voltage regulators.

Abstract: In order to avoid a ripple voltage and to ensure that an adequate voltage is applied to a load even when a supply voltage is low, the duty ratio of a PFM type switching regulator is provided with a supply voltage dependency. A control circuit for a PFM type switching regulator according to a first embodiment comprises a first circuit for producing a first output signal based on a difference between a fed back portion of a regulated output voltage of a PFM type switching regulator and a first reference voltage; and a second circuit for producing a second output signal based on a second reference voltage, the second output signal being used for modulating the first output signal and including a pulse signal having successive pulses the width of which is dependent upon the value of the second reference voltage so that the duty cycle of the PFM type voltage regulator is dependent upon the second reference voltage.

Abstract: A synchronous rectifying type switching regular circuit operable in a high efficiency is obtained, while a reverse current flowing through a coil is not used to charge a power supply. In a synchronous rectifying type switching regulator circuit for alternately turning ON/OFF a first switch element for controlling a current of a coil employed in the switching regulator and a second switch element connected parallel to a commutation diode, a capacitor is added to an input of the switching regulator circuit; a third switch element is interposed between a power supply such as a battery and the capacitor; and when the first switch element is turned ON, the third switch element is turned ON, whereas when the first switch element is turned OFF, the third switch element is turned OFF.

Abstract: A charge/discharge control circuit is provided for an electric power source apparatus in which a service life is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge voltage detection circuit and a control circuit are connected in parallel to a secondary cell which is an electric power source, wherein the control circuit detects a condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal Vs for controlling a power supply to an external equipment and a charge by an external power source and controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the voltage dividing circuit.

Abstract: Current drawn from a power supply at the start-up of a voltage regulator is reduced by providing a clamp circuit to clamp the input voltage of an output transistor in the voltage regulator for a predetermined period of time after start-up. The voltage regulator preferably comprises an error amplifier for producing an error signal depending upon the difference between a divided portion of the regulated output voltage and a reference voltage, the error signal for controlling the output transistor to regulate the output voltage thereof, and the clamp circuit includes a charge storage device connected to a current source, and a switch circuit having a first terminal connected to a first voltage sufficient to place the output transistor in a high-resistance state, a second terminal connected to the error signal and the input of the output transistor, and a third terminal connected to the charge storage device for controlling an ON/OFF state of the switch circuit.

Abstract: A charge/discharge control circuit is provided for an electric power source apparatus in which a service life is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge voltage detection circuit and a control circuit are connected in parallel to a secondary cell which is an electric power source, wherein the control circuit detects a condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal Vs for controlling a power supply to an external equipment and a charge by an external power source and controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the voltage dividing circuit.

Abstract: A charge/discharge control circuit is provided for an electric power source apparatus in which a service life is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge voltage detection circuit and a control circuit are connected in parallel to a secondary cell which is an electric power source, wherein the control circuit detects a condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal Vs for controlling a power supply to an external equipment and a charge by an external power source and controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the voltage dividing circuit.

Abstract: A switching regulator of which efficiency is increased while the switching regulator is operated under low load condition is disclosed. The switching regulator is arranged by: a reference voltage circuit for producing a reference voltage; an error amplifier for entering thereinto the reference voltage and a measuring voltage produced by subdividing an output voltage from the switching regulator and for amplifying a difference voltage between the reference voltage and the measuring voltage; an oscillator circuit for outputting an oscillator signal; a PWM comparator for comparing an output voltage of the error amplifier with an output voltage of the oscillator circuit; load detecting means for detecting an output load current; and efficiency varying means for varying an efficiency of the switching regulator in response to load conditions detected by the load detecting means.

Abstract: A charge/discharge control circuit for controlling the charging and discharging of a secondary cell has a voltage dividing circuit for dividing an output voltage of the secondary cell, which may comprise plural cells, an overcharge detection circuit for detecting an overcharge state of the secondary cell, an overdischarge detection circuit for detecting an overdischarge state of the secondary cell, and a control circuit for receiving and processing an output signal of the overcharge detecting circuit and the overdischarge detecting circuit and controlling the switch. In a preferred embodiment, an overcharge reference voltage source used for the overcharge voltage detection circuit is used also as an overdischarge reference voltage source for the overdischarge voltage detection circuit.

Abstract: A charge/discharge control circuit is provided for an electric power source apparatus in which a service life is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge voltage detection circuit and a control circuit are connected in parallel to a secondary cell which is an electric power source, wherein the control circuit detects a condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal Vs for controlling a power supply to an external equipment and a charge by an external power source and controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the voltage dividing circuit.