Abstract: An oscillator circuit is disclosed that includes a first oscillation part configured to output a first oscillation output by charging and discharging a first capacitor, and a second oscillation part configured to output a second oscillation output by charging and discharging a second capacitor. The second oscillation part includes a phase difference detection part configured to detect the phase difference between the first oscillation output and the second oscillation output, and a charging current and discharge current control part configured to control the charging current and the discharge current of the second capacitor in accordance with the phase difference detected by the phase difference detection part so that the second oscillation output synchronizes with the first oscillation output.

Abstract: A digital signal processing apparatus for converting an analog signal to a digital signal and digitally processing the digital signal is disclosed. The apparatus includes a modulation part for performing pulse density modulation on the analog signal and outputting a pulse density modulation signal, a memory for storing a conversion program for converting the pulse density modulation signal to pulse code modulation data, and a CPU for receiving the pulse density modulation signal from the modulation part and converting the received pulse density modulation signal to pulse code modulation data according to the conversion program stored in the memory.

Abstract: A battery pack is disclosed. The battery pack includes a battery; a current detecting unit which detects charging and discharging currents of the battery and outputs an analog signal corresponding to the charging and discharging currents; a modulating unit which modulates the analog signal to be a PDM (pulse density modulation) signal by applying a PDM modulation to the analog signal; a memory in which a conversion program for converting the PDM signal into PCM (pulse code modulation) data and a remaining battery charge calculating program for calculating a remaining battery charge by accumulating the PCM data are stored; and a CPU, which converts the PDM signal into the PCM data which are digital data by being supplied the PDM signal from the modulating unit while executing the conversion program stored in the memory, and calculates the remaining battery charge by accumulating the PCM data while executing the remaining battery charge calculating program stored in the memory.

Abstract: A disclosed circuit for detecting remaining battery capacity includes: a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

Abstract: A battery pack with a charge control function includes a charge protection circuit and a charge control circuit. The charge control circuit turns a discharge control switch on or off to control a discharge current which flows from a secondary battery to a load and also turns a charge control switch on or off to control a charge current which flows from a charger to the secondary battery. When an abnormal voltage is input, the charge control circuit turns the charge control switch on or off to stop the charging of the secondary battery through the charger.

Abstract: The present invention provides an overcharge/overdischarge detection apparatus includes a detection terminal being in an open state, a detection part for detecting application of voltage to the detection terminal, a switch part for switchably connecting and disconnecting a secondary battery with an external circuit, and a control part for controlling the switch part in a case where the detection part detects the application of voltage to the detection terminal.

Abstract: A semiconductor device having a positive side of a power supply voltage set as a common potential is disclosed. The semiconductor device includes a power supply circuit that generates a power supply having a negative potential side set to a predetermined voltage based on the common potential. In the semiconductor device, a constant voltage is generated between the common potential and an output voltage of the power supply circuit.

Abstract: An oscillator circuit is disclosed that includes a first oscillation part configured to output a first oscillation output by charging and discharging a first capacitor, and a second oscillation part configured to output a second oscillation output by charging and discharging a second capacitor. The second oscillation part includes a phase difference detection part configured to detect the phase difference between the first oscillation output and the second oscillation output, and a charging current and discharge current control part configured to control the charging current and the discharge current of the second capacitor in accordance with the phase difference detected by the phase difference detection part so that the second oscillation output synchronizes with the first oscillation output.

Abstract: In a secondary battery protection circuit (200A) having a protection arrangement (210, 220, 230, 240, 250A) for protecting a secondary battery (300), by turning a discharge control switch (FET1) and a charge control switch (FET2) on and off, so as to prevent the secondary battery from overdischarging and overcharging, the secondary battery protection circuit further has a security arrangement (260, 270) for precluding counterfeit goods of a secondary pack. The security arrangement has an interface circuit (260) for interfacing to a portable unit body (500) and an authentication circuit (270) for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

Abstract: A protection circuit is disclosed that issues an instruction to blow a fuse connected to a power source in response to detection of an abnormality of a voltage of the power source. The protection circuit includes a time control unit that detects the voltage of the power source and controls the length of time from the detection of the abnormality of the voltage of the power source to the issue of the instruction to blow the fuse in accordance with the detected voltage.

Abstract: A lithium-ion battery protection module is disclosed. The lithium-ion battery protection module includes a control IC chip. The control IC chip includes a discharge overcurrent detector, a charge overcurrent detector, and a temperature detector. The control IC chip is mounted on a charge control FET and a discharge control FET so as to highly accurately detect the temperature of the charge control FET and the discharge control FET.

Abstract: The present invention provides an overcharge/overdischarge detection apparatus includes a detection terminal being in an open state, a detection part for detecting application of voltage to the detection terminal, a switch part for switchably connecting and disconnecting a secondary battery with an external circuit, and a control part for controlling the switch part in a case where the detection part detects the application of voltage to the detection terminal.

Abstract: A semiconductor device includes a substrate, a well region formed in the substrate, a field effect transistor formed in the well region, and a diffused region, formed across the well region and the substrate for applying back gate potential to the well region, and forming a PN junction together with its periphery. The field effect transistor and the PN junction are connected between terminals for absorbing excess current so that an internal circuit connected to the terminals is protected.

Abstract: A disclosed current detection circuit includes a current/voltage converting element for generating a voltage in accordance with an input current, a reference voltage generation circuit for generating a reference voltage, the reference voltage generation circuit having an element configuration for setting a predetermined temperature characteristic to the reference voltage, and a comparator for outputting an output signal in accordance with a magnitude relation between a voltage converted in the current/voltage converting element and the reference voltage generated in the reference voltage generation circuit.

Abstract: A battery pack with a charge control function includes a charge protection circuit and a charge control circuit. The charge control circuit turns a discharge control switch on or off to control a discharge current which flows from a secondary battery to a load and also turns a charge control switch on or off to control a charge current which flows from a charger to the secondary battery. When an abnormal voltage is input, the charge control circuit turns the charge control switch on or off to stop the charging of the secondary battery through the charger.

Abstract: A semiconductor device includes a substrate, a well region formed in the substrate, a field effect transistor formed in the well region, and a diffused region, formed across the well region and the substrate for applying back gate potential to the well region, and forming a PN junction together with its periphery. The field effect transistor and the PN junction are connected between terminals for absorbing excess current so that an internal circuit connected to the terminals is protected.

Abstract: A head amplifier circuit supplies a writing current, having a direction in accordance with recording information, to a head for recording information on a recording medium. The head amplifier circuit includes a reference voltage generating portion for generating a reference voltage, a constant current generating portion for generating a constant current based on the reference voltage generated by the reference voltage generating portion, and a grounding portion. During one period of time, the constant current generating portion supplies the constant current to a first end of the head and the grounding portion grounds a second end of the head. During another period of time, the constant current generating portion supplies the constant current to the second end of the head and the grounding portion grounds the first end of the head.

Abstract: An offset voltage trimming circuit for sending a current from a constant-current source to a trimming resistor and thus obtaining an offset voltage, the offset voltage trimming circuit having a Zener diode with a temperature characteristic of zero, a transistor connected so as to form a diode and connected in series to the Zener diode, a current-mirror circuit connected to the transistor and a second resistor connected in series to the current-mirror circuit and having a temperature characteristic identical to that of the trimming resistor, with the current being supplied to the trimming resistor from the current-mirror circuit in order to prevent changes in the offset voltage due to changes in temperature.

Abstract: A differential amplifier circuit for amplifying and outputting a differential voltage between a pair of input terminals includes a voltage-to-current converting circuit, a current amplifying circuit, and a current-to-voltage converting circuit. In the voltage-to-current converting circuit, each of the input terminals is connected with one end of each of resistances, a potential on the other end of each of the resistances is kept constant by a feedback circuit, and an electric current corresponding to the differential voltage flows into a first differential circuit. In the current amplifying circuit, the electric current corresponding to the differential voltage and flowing into the first differential circuit is amplified and then flows into a second differential circuit. In the current-to-voltage converting circuit, an electric current outputted from the current amplifying circuit is converted to a voltage to be outputted.

Abstract: A voltage-current conversion circuit outputting a current corresponding to a difference between a first input voltage and a second input voltage, the voltage-current conversion circuit having a first current-mirror circuit supplied with the first input voltage as a power source and comprising at least one pair of transistors, a second current-mirror circuit supplied with the second input voltage as a power source and comprising at least one pair of transistors, a resistor connected between one of the pair of transistors of the first current-mirror circuit and one of the transistors of the second current-mirror circuit, and a third current-mirror circuit having a current source transistor supplying current to one of the pair of transistors of the first current-mirror circuit and another current source transistor supplying current to one of the pair of transistors of the second current-mirror circuit, a current output terminal being connected to one of the current source transistors.