Physical quantity detection circuit and physical quantity sensor device
AssigneePanasonic Corporation
InventorsFumihito Inukai, Seiichi Muroya, Yoichi Kaino
Life of this patent
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Abstract
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.
Claims9
A physical quantity detection circuit used for a physical quantity sensor that outputs a sensor signal according to a physical quantity given externally, the circuit comprising:
- a first phase adjustment circuit configured to receive a reference clock having a frequency corresponding to the frequency of the sensor signal and operate in synchronization with a first operation clock having a frequency higher than the frequency of the reference clock, to delay a transition edge of the reference clock by a predetermined number of pulses of the first operation clock:
- and
- a detection circuit configured to detect a physical quantity signal corresponding to the physical quantity from the sensor signal using a transition edge of the reference clock delayed by the first phase adjustment circuit as the reference,
- wherein the first phase adjustment circuit includes
- a phase adjustment counter configured to start counting the number of generated pulses of the first operation clock in response to a transition edge of the reference clock and generate a timing signal once the number of generated pulses reaches a predetermined value, and
- the detection circuit includes
- an analog-to-digital converter circuit configured to convert the sensor signal to a digital sensor signal,
- a detection signal generator circuit configured to generate a digital detection signal corresponding to a sine wave signal in response to a transition edge of the timing signal generated by the phase adjustment counter, and
- a multiplier circuit configured to multiply the digital sensor signal obtained by the analog-to-digital converter circuit by the digital detection signal generated by the detection signal generator circuit, to detect the physical quantity signal.
A physical quantity detection circuit used for a physical quantity sensor that outputs a sensor signal according to a physical quantity given externally, the circuit comprising:
- an analog-to-digital converter circuit configured to convert the sensor signal to a digital sensor signal;
- a detection signal generator circuit configured to generate a digital detection signal corresponding to a sine wave signal in response to a transition edge of a reference clock having a frequency corresponding to the frequency of the sensor signal;
- a phase adjustment circuit configured to receive the digital sensor signal obtained by the analog-to-digital converter circuit and operate in synchronization with an operation clock having a frequency higher than the frequency of the reference clock, to delay the digital sensor signal by a predetermined number of pulses of the operation clock;
- and
- a multiplier circuit configured to multiply the digital sensor signal delayed by the phase adjustment circuit by the digital detection signal generated by the detection signal generator circuit, to detect a physical quantity signal corresponding to the physical quantity.
Dependencies are inferred from the claim text.