摘要:
A cascade-type variable-order delta-sigma modulator with low power consumption that can change the number of stages of the quantization loops, which are connected in a cascade configuration, to an optimum number depending on peripheral circuitries in a configuration as simple as possible. The present invention includes first to nth stages of delta-sigma modulating type quantization loops (n is an integer equal to or more than 2) connected in a cascade configuration, and a noise rejecting circuit. Each quantization loop quantizes an input signal, outputs the quantization result, and feeds back the quantization result to itself. The noise rejecting circuit rejects a quantization noise of the first stage of quantization loop, and comprises (n−1) selectors for activating and de-activating the respective output signals of the second and succeeding stages of the quantization loops in compliance with the control signal.
摘要:
A cascade-type variable-order delta-sigma modulator with low power consumption that can change the number of stages of the quantization loops, which are connected in a cascade configuration, to an optimum number depending on peripheral circuitries in a configuration as simple as possible. The present invention includes first to nth stages of delta-sigma modulating type quantization loops (n is an integer equal to or more than 2) connected in a cascade configuration, and a noise rejecting circuit. Each quantization loop quantizes an input signal, outputs the quantization result, and feeds back the quantization result to itself. The noise rejecting circuit rejects a quantization noise of the first stage of quantization loop, and comprises (n−1) selectors for activating and de-activating the respective output signals of the second and succeeding stages of the quantization loops in compliance with the control signal.
摘要:
An inertial velocity sensor signal processing circuit (12, 13, 14) used together with an inertial velocity sensor element (11) includes a first signal processing circuit (12, 13) which operates with a first clock (CLK1) and a second signal processing circuit (14) which operates with a second clock (CLK2) which does not synchronize with the first clock.
摘要:
A first second- or higher-order delta sigma modulator and a second second- or higher-order delta sigma modulator having a notch characteristic are cascaded together, and a delayed signal of the output of the first delta sigma modulator and a differential signal of the output of the second delta sigma modulator are added together. The amount of feedback from the output portion to the input portion of the first delta sigma modulator and the amount of feedback from the output portion to the input portion of the second delta sigma modulator are made the same.
摘要:
By using a selector, an output of a delta sigma modulator having a quantizer for quantizing a signal is selectively supplied to one of a first D/A converter having a linear amplifier and a second D/A converter having a digital amplifier. Further, the number of quantization levels of the quantizer, the sampling frequency, or the order of a transfer function of the delta sigma modulator is selected by a control signal selector in conjunction with the selector. An output of the first D/A converter is supplied to a line terminal, while an output of the second D/A converter is supplied to a headphone terminal.
摘要:
In a delta sigma modulator including first and second integration circuits connected in cascade, each as a component thereof, first and second power source terminals for supplying first and second different power source voltages to the first and second integration circuits are provided. The first power source voltage is supplied to the former-stage first integration circuit having a SNR which is largely affected by the magnitude of the power source voltage. The second power source voltage lower than the first power source voltage is supplied to the latter-stage second integration circuit having a SNR which is not largely affected by the magnitude of the power source voltage.
摘要:
A delta-sigma modulation quantization loop, comprising an integration circuit for integrating the difference between an analog input signal and a feedback reference voltage, a local quantizer for quantizing the output of the integration circuit into a digital signal, and a DA converter for generating the feedback reference voltage from the digital output of the local quantizer, is used as a single stage, and a plurality of the stages are cascade-connected. In the second-stage and subsequent modulation quantization loops, the difference signal between the input of the local quantizer of the previous stage and the output of the DA converter of the previous stage is used as an analog input signal. The feedback reference voltages of the respective delta-sigma modulation quantization loops are set individually so as to be higher than the specified maximum voltage of the analog input signal to limit the gains of the respective delta-sigma modulation quantization loops. Gain setting devices are provided in a noise reduction circuit to roughly compensate the gains limited in the respective delta-sigma modulation quantization loops.
摘要:
A first second- or higher-order delta sigma modulator and a second second- or higher-order delta sigma modulator having a notch characteristic are cascaded together, and a delayed signal of the output of the first delta sigma modulator and a differential signal of the output of the second delta sigma modulator are added together. The amount of feedback from the output portion to the input portion of the first delta sigma modulator and the amount of feedback from the output portion to the input portion of the second delta sigma modulator are made the same.
摘要:
A delta-sigma modulation quantization loop, comprising an integration circuit for integrating the difference between an analog input signal and a feedback reference voltage, a local quantizer for quantizing the output of the integration circuit into a digital signal, and a DA converter for generating the feedback reference voltage from the digital output of the local quantizer, is used as a single stage, and a plurality of the stages are cascade-connected. In the second-stage and subsequent modulation quantization loops, the difference signal between the input of the local quantizer of the previous stage and the output of the DA converter of the previous stage is used as an analog input signal. The feedback reference voltages of the respective delta-sigma modulation quantization loops are set individually so as to be higher than the specified maximum voltage of the analog input signal to limit the gains of the respective delta-sigma modulation quantization loops. Gain setting devices are provided in a noise reduction circuit to roughly compensate the gains limited in the respective delta-sigma modulation quantization loops.
摘要:
A physical quantity detection circuit (12) is used for a physical quantity sensor (10) that outputs a sensor signal according to a physical quantity given externally. A phase adjustment circuit (100) receives a reference clock (CKref) and operates in synchronization with an operation clock (CKa), to delay a transition edge of the reference clock by a predetermined number of pulses of the operation clock. A detection circuit (104) detects a physical quantity signal from the sensor signal (Ssnc) using a transition edge of a clock (SSS) from the phase adjustment circuit (100) as the reference.