摘要:
PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit device and an oscillation frequency calibration method which can reduce calibration operations of the oscillation frequency of an oscillator. SOLUTION: The semiconductor integrated circuit device includes a DCO 50 and a storage part 42 that stores a temperature coefficient of an oscillation frequency and an absolute value of the oscillation frequency, which should be set in the DCO 50, corresponding to potential obtained from a voltage source 20 that changes with a monotonic characteristic with respect to temperature. COPYRIGHT: (C)2011,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide a voltage controlled oscillator capable of being treated as a lumped constant circuit, having small size and capable of obtaining an oscillation frequency in a high frequency band. SOLUTION: A resonance part 1 in the voltage controlled oscillator has variable capacitance elements 13, 14 whose electrostatic capacitance varies in accordance with a control voltage for frequency control input from the outside, and an inductance element 11, an amplifying part 21 amplifies a frequency signal from the resonance part 1, and a feedback part 2, having feedback capacitance elements 22, 23 and allowing the frequency signal amplified in the amplifying part 21 to be fed back to the resonance part 1, forms an oscillation loop together with the amplifying part 21 and the resonance part 1. Further, the resonance part 1 and the feedback part 2 are provided on a quartz-crystal substrate 5. COPYRIGHT: (C)2011,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide a piezoelectric oscillation circuit with failure detection circuit, for detecting a failure with high accuracy, and a physical quantity sensor. SOLUTION: The piezoelectric oscillation circuit with failure detection circuit includes: an oscillating part 10 including a piezoelectric vibrator 11 and an amplifying part 12 for oscillation operation; a current detecting part 20 for detecting current flowing between the oscillating part 10 and a DC power supply 40; and a determining part 30 for determining a failure of the piezoelectric vibrator 11 on the basis of the current detected by the current detecting part 20. The amplifying part 12 includes three or more inverting amplifier circuits connected in series. The current detecting part 20 includes a resistor 21 for connecting the oscillating part 10 and power supply potential of the DC power supply 40. The determining part 30 can determine a failure of the piezoelectric vibrator 11 on the basis of voltage across the resistor 21. COPYRIGHT: (C)2011,JPO&INPIT