Abstract: According to one embodiment, a current detection circuit (12) includes: a detection resistor (Rs) provided between a solenoid valve (106) and a solenoid driver (11); an amplification unit (121) configured to amplify a detected voltage of the detection resistor (Rs); an AD converter (122) that is driven by a reference voltage (Vref) generated based on a reference current (Iref) and configured to convert an output voltage from the amplification unit (121) into a digital value and output the digital value as a detected current value (D1); and a correction unit configured to perform a correction on the detected current value (D1).

Abstract: According to one embodiment, a current detection circuit (12) includes: a detection resistor (Rs) provided between a solenoid valve (106) and a solenoid driver (11); an amplification unit (121) configured to amplify a detected voltage of the detection resistor (Rs); an AD converter (122) that is driven by a reference voltage (Vref) generated based on a reference current (Iref) and configured to convert an output voltage from the amplification unit (121) into a digital value and output the digital value as a detected current value (D1); and a correction unit configured to perform a correction on the detected current value (D1).

Abstract: The A/D converter converting an analog input signal into a digital output signal is constructed with a band pass ?? modulator. The band pass ?? modulator includes: a resonator showing a band-pass characteristic at a predetermined frequency and an attenuation characteristic at another frequency; a quantizer; and a local D/A converter. A signal of difference between the analog input signal and a local analog signal of the local D/A converter is supplied to the resonator. The A/D converter further includes an adder for supplying the analog input signal to an input of the quantizer. In addition, signal transmission circuits for reducing the influence of spike noise of the quantizer on the input to the resonator are connected between an input of the adder and an input of resonator selectively. The A/D converter constructed with the band pass ?? modulator is improved in S/N ratio.

Abstract: The A/D converter converting an analog input signal into a digital output signal is constructed with a band pass ?? modulator. The band pass ?? modulator includes: a resonator showing a band-pass characteristic at a predetermined frequency and an attenuation characteristic at another frequency; a quantizer; and a local D/A converter. A signal of difference between the analog input signal and a local analog signal of the local D/A converter is supplied to the resonator. The A/D converter further includes an adder for supplying the analog input signal to an input of the quantizer. In addition, signal transmission circuits for reducing the influence of spike noise of the quantizer on the input to the resonator are connected between an input of the adder and an input of resonator selectively. The A/D converter constructed with the band pass ?? modulator is improved in S/N ratio.

Abstract: In a first-order complex band-pass filter, multiplexers are alternately switched over between time intervals of phases A and B, where the multiplexers includes two multiplexers provided at input and output stages, and a multiplexer provided in a feedback circuit of each of first-order filters and being switching over whether to invert a sign of a feedback signal. Then in a circuit part sandwiched between the multiplexers, a processing performed by an I circuit part and a processing performed by a Q circuit part are alternately switched over so that a sign of a signal inputted to an adder is inverted.

Abstract: In a first-order complex band-pass filter, multiplexers are alternately switched over between time intervals of phases A and B, where the multiplexers includes two multiplexers provided at input and output stages, and a multiplexer provided in a feedback circuit of each of first-order filters and being switching over whether to invert a sign of a feedback signal. Then in a circuit part sandwiched between the multiplexers, a processing performed by an I circuit part and a processing performed by a Q circuit part are alternately switched over so that a sign of a signal inputted to an adder is inverted.