Abstract: Provided is a physical quantity sensor capable of improving physical quantity detection precision thereof. The physical quantity sensor includes a bridge resistance type physical quantity detection element for generating a voltage based on a bias current and a physical quantity, a current supply circuit for supplying the bias current to the physical quantity detection element, and a leakage current control circuit for causing leakage currents flowing when switches of the current supply circuit are in an off state to flow into a ground terminal.

Abstract: To provide a variable voltage dividing circuit capable of changing voltage values of a detection point and a release point along with a change in power supply voltage without changing a hysteresis width.

Abstract: Provided is a constant current circuit capable of low current consumption operation, which is prevented from repeating a start-up state and a zero steady state and entering an oscillating state when power is activated. When power is activated, until a node (A) reaches a start-up state, an excitation current is continued to be supplied to a node (B), to thereby reliably start up the constant current circuit in a short period of time without repeating the start-up state and the zero steady state.

Abstract: Provided is a magnetic sensor circuit of low power consumption, in which a magnetic detection level less depends on a resistance value of an internal resistor of a power source. A comparator circuit compares a voltage which is based on a magnetic field and generated after sampling under a state in which power is supplied to mainly a Hall element and an amplifier circuit to drop a power supply voltage, with a reference voltage after sampling under the same state. Both the voltages are generated based on the power supply voltage dropped by an internal resistor. Therefore, the magnetic detection level less depends on a resistance value of the internal resistor. The comparator circuit may be disabled during a sample period, and the Hall element and the amplifier circuit may be disabled during a comparison period, and hence power consumption of the magnetic sensor circuit is reduced by corresponding power.

Abstract: A variable frequency oscillating circuit has an oscillating circuit that undergoes an oscillation operation. The oscillating circuit has at least one inverter and at least one capacitor forming a circuit in a ring oscillator configuration. A current circuit outputs a current based on a frequency control signal controlling a frequency of a clock signal output from the oscillating circuit. A pulse generating circuit generates a pulse when the frequency control signal is switched from low to high and from high to low. The oscillating circuit stops an oscillation operation by stopping a charge/discharge operation of the at least one capacitor when the pulse is generated by the pulse generating circuit.

Abstract: Provided is a magnetic sensor device including: a switching circuit that controls switching of a terminal pair of the magnetoelectric conversion element to which a supply voltage is applied and a terminal pair to which detection voltage of a magnetic intensity is output; a differential amplifier that differentially amplifies the detection voltage; a first capacitor connected to a first output terminal of the differential amplifier; a second switch connected to a second output terminal of the differential amplifier; a comparator that has a first input terminal connected to the first capacitor and a second input terminal connected to the second switch; a first switch connected between the first input terminal and an output terminal of the comparator; and a second capacitor connected to the second input terminal of the comparator; and a detection voltage setting circuit connected to the second capacitor, in which effects of respective offset voltages of the magnetoelectric conversion element, the amplifier, and

Abstract: A scanning circuit has path switches connected between a plurality of data flip-flop circuits of the scanning circuit for sequentially reading an output signal in synchronism with a clock. A plurality of control signal lines select the path switches to arbitrarily skip reading of the flip-flop circuits that do not require the scanning circuit and always fix a potential of the skipped data flip-flop circuit. Only the arbitrary data is read, and in the case where unnecessary data exists, reading is skipped, to thereby increase the read rate.

Abstract: Provided is a sensor circuit that is small in circuit scale, but is capable of temperature compensation. A reference voltage circuit (BL1) which compensates a temperature includes only a voltage divider circuit, and hence the sensor circuit is small in circuit scale. The sensor circuit is also capable of temperature compensation because temperature changes of reference voltages (VTH11 and VTH12) and reference voltages (VTH21 and VTH22) match a temperature change of an output signal (OUTA) of an amplifier circuit (AMP1) which is caused by a temperature change of an output signal of a Hall element (HAL1).

Abstract: Provided is a sensor circuit that is small in circuit scale, but is capable of temperature compensation. A reference voltage circuit (BL1) which compensates a temperature includes only a voltage divider circuit, and hence the sensor circuit is small in circuit scale. The sensor circuit is also capable of temperature compensation because temperature changes of a reference voltage (VTH1) and a reference voltage (VTH2) match a temperature change of an output signal (OUTA) of an amplifier circuit (AMP1) which is caused by a temperature change of an output signal of a Hall element (HAL1).

Abstract: To provide a variable voltage dividing circuit capable of changing voltage values of a detection point and a release point along with a change in power supply voltage without changing a hysteresis width.

Abstract: Provided is a chopper amplifier circuit capable of eliminating an influence of a slew rate of an amplifier and suppressing spike generation to thereby obtain an output signal having little harmonic distortion. The chopper amplifier circuit according to the present invention includes: a first chopper circuit for chopping an input signal by a first pulse and a second pulse shifted from each other in phase by a half cycle, switching a relation of connection between an input terminal pair and an output terminal pair at a timing of the chopping, and outputting the input signal as a modulated signal; an amplifier for amplifying the modulated signal and outputting the modulated signal thus amplified as an amplified signal; a first sample hold circuit for holding the amplified signal at the first pulse and outputting the amplified signal at the second pulse; and a second sample hold circuit for holding the amplified signal at the second pulse and outputting the amplified signal at the first pulse.

Abstract: Provided is a variable frequency oscillating circuit which has a small circuit size and is unlikely to cause a semiconductor device to malfunction. One oscillating circuit (3) is used, and thus the circuit size is not increased. When a frequency control signal (SF) is switched, constant currents (I2 and I3) are each switched, and ringing is generated in the constant currents (I2 and I3), a pulse signal (SP) becomes high to be input to the oscillating circuit (3) during the ringing, and a clock signal (CLK) output from the oscillating circuit (3) in response to the pulse signal (SP) is fixed to low, with the result that the oscillating circuit (3) stops a regular oscillation. As a result, a clock signal having an unintended frequency is not generated.

Abstract: Provided is a chopper amplifier circuit capable of reducing an offset voltage of a sensor bridge and temperature characteristics of the offset voltage. An offset adjusting voltage generation circuit for generating a voltage equal to an offset voltage of a sensor bridge and an offset temperature characteristics adjusting voltage generation circuit for generating a voltage having temperature characteristics equal to those of the offset voltage are provided. These output voltages are chopper-modulated and subtracted from a chopper-modulated output signal of the sensor bridge.

Abstract: Provided is a chopper amplifier circuit capable of eliminating an influence of a slew rate of an amplifier and suppressing spike generation to thereby obtain an output signal having little harmonic distortion. The chopper amplifier circuit according to the present invention includes: a first chopper circuit for chopping an input signal by a first pulse and a second pulse shifted from each other in phase by a half cycle, switching a relation of connection between an input terminal pair and an output terminal pair at a timing of the chopping, and outputting the input signal as a modulated signal; an amplifier for amplifying the modulated signal and outputting the modulated signal thus amplified as an amplified signal; a first sample hold circuit for holding the amplified signal at the first pulse and outputting the amplified signal at the second pulse; and a second sample hold circuit for holding the amplified signal at the second pulse and outputting the amplified signal at the first pulse.

Abstract: Provided is a chopper amplifier circuit capable of reducing an offset voltage of a sensor bridge and temperature characteristics of the offset voltage. An offset adjusting voltage generation circuit for generating a voltage equal to an offset voltage of a sensor bridge and an offset temperature characteristics adjusting voltage generation circuit for generating a voltage having temperature characteristics equal to those of the offset voltage are provided. These output voltages are chopper-modulated and subtracted from a chopper-modulated output signal of the sensor bridge.

Abstract: To provide a resistor circuit with which a resistance ratio among voltage division resistors in a semiconductor integrated circuit can be realized with high accuracy. The resistor circuit of the present invention includes: a reference resistor portion; and a resistor portion including resistor elements and fuse connected in parallel with the resistor elements, respectively, for trimming the resistor elements. The resistor elements are arranged in order from the resistor element having a largest resistance value so as to be adjacent to the reference resistor portion in the periphery of the reference resistor portion. As a result, it is possible to obtain accurately the ratio between a resistance value of a reference resistor and a desired resistance value determined with the ratio from the resistance value of the reference resistor.

Abstract: A scanning circuit has path switches connected between a plurality of data flip-flop circuits of the scanning circuit for sequentially reading an output signal in synchronism with a clock. A plurality of control signal lines select the path switches to arbitrarily skip reading of the flip-flop circuits that do not require the scanning circuit and always fix a potential of the skipped data flip-flop circuit. Only the arbitrary data is read, and in the case where unnecessary data exists, reading is skipped, to thereby increase the read rate.

Abstract: To provide a resistor circuit with which a resistance ratio among voltage division resistors in a semiconductor integrated circuit can be realized with high accuracy. The resistor circuit of the present invention includes: a reference resistor portion; and a resistor portion including resistor elements and fuse connected in parallel with the resistor elements, respectively, for trimming the resistor elements. The resistor elements are put to be arranged in order from the resistor element having a largest resistance value so as to be adjacent to the reference resistor portion in the periphery of the reference resistor portion. As a result, it is possible to obtain accurately the ratio between a resistance value of a reference resistor and a desired resistance value determined with the ratio from the resistance value of the reference resistor.