1. A voltage controlled oscillator, comprising:
a resonator configured to oscillate with an initial oscillation frequency during a starting period of oscillation and with a steady oscillation frequency during a steady state oscillation, the resonator including a film bulk acoustic resonator having a series resonance frequency higher than the steady oscillation frequency; and
a negative resistance circuit connected to the resonator, configured to drive the resonator, the negative resistance circuit having a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.
2. The voltage controlled oscillator of claim 1, wherein the resonator comprises:
a phase adjuster connected to the film bulk acoustic resonator; and
a reactance controller connected to the film bulk acoustic resonator or the phase adjuster, the reactance controller having a reactance controlled by a control voltage.
3. The voltage controlled oscillator of claim 1, wherein the initial oscillation frequency is in a range higher than the series resonance frequency and lower than a parallel resonance frequency of the film bulk acoustic resonator.
4. The voltage controlled oscillator of claim 1, wherein, at the series resonance frequency, a ratio of a maximum reactance difference of a reactance controller in a variable range of a control voltage to reactance of the reactance controller at a center value of the control voltage is in a range larger than 0.5, and a ratio of reactance of the reactance controller at the center value of the control voltage to reactance attributable to an electrostatic capacity of the film bulk acoustic resonator is in a range not less than 0.30 and not more than 1.50.
5. The voltage controlled oscillator of claim 4, wherein a ratio of the maximum reactance difference to a difference between a maximum reactance value and a minimum reactance value of the film bulk acoustic resonator is in a range not less than 0.05 and not more than 0.30.
6. A voltage controlled oscillator, comprising:
a resonator driven by a negative resistance circuit, configured to oscillate with an initial oscillation frequency during a starting period of oscillation and with a steady oscillation frequency during a steady state oscillation, the resonator including a film bulk acoustic resonator having a series resonance frequency higher than the steady oscillation frequency, wherein
the negative resistance circuit has a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.
7. A frequency synthesizer, comprising:
a voltage controlled oscillator including a plurality of film bulk acoustic resonators having different resonance frequencies, configured to generate an oscillation signal;
a first frequency divider configured to divide the oscillation signal from the voltage controlled oscillator and to generate a divided oscillation signal;
a second frequency divider configured to divide a reference signal and to generate a divided reference signal;
a phase comparator configured to compare phases of the divided oscillation signal and the divided reference signal and to generate a phase error signal;
a control voltage generator configured to generate a control voltage for the voltage controlled oscillator based on the phase error signal; and
a control circuit configured to generate a control signal based on the control voltage so as to select the film bulk acoustic resonators, and to control an oscillation frequency of the oscillation signal.
8. The frequency synthesizer of claim 7, wherein the voltage controlled oscillator comprises:
a resonator configured to resonate with an initial oscillation frequency during a starting period of oscillation and with a steady oscillation frequency during a steady state oscillation, the resonator including one of the film bulk acoustic resonators having a series resonance frequency higher than the steady oscillation frequency; and
a negative resistance circuit connected to each of the film bulk acoustic resonators, configured to drive the resonator, the negative resistance circuit having a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.
9. The frequency synthesizer of claim 8, wherein the resonator comprises:
a phase adjuster connected to the one of the film bulk acoustic resonators; and
a reactance controller connected to the film bulk acoustic resonator or the phase adjuster, the reactance controller having reactance controlled by the control voltage.
10. The frequency synthesizer of claim 8, wherein the initial oscillation frequency is in a range higher than the series resonance frequency and lower than a parallel resonance frequency of the one of the film bulk acoustic resonators.
11. The frequency synthesizer of claim 8, wherein, at the series resonance frequency, a ratio of a maximum reactance difference of a reactance controller in a variable range of the control voltage to reactance of the reactance controller at a center value of the control voltage is in a range larger than 0.5, and a ratio of reactance of the reactance controller at the center value of the control voltage to reactance attributable to an electrostatic capacity of the one of the film bulk acoustic resonators is in a range not less than 0.30 and not more than 1.50.
12. The frequency synthesizer of claim 11, wherein a ratio of the maximum reactance difference to a difference between a maximum reactance value and a minimum reactance value of the one of the film bulk acoustic resonators is in a range not less than 0.05 and not more than 0.30.
13. A frequency synthesizer, comprising:
a voltage controlled oscillator including a plurality of film bulk acoustic resonators having different resonance frequencies, configured to generate an oscillation signal controlled by a control circuit by dividing the oscillation signal from the voltage controlled oscillator to generate a divided oscillation signal, by dividing a reference signal to generate a divided reference signal, by comparing phases of the divided oscillation signal and the divided reference signal to generate a phase error signal, and by generating a control voltage for the voltage controlled oscillator based on the phase error signal, wherein
the control circuit generates a control signal based on the control voltage so as to select the film bulk acoustic resonators, and controls an oscillation frequency of the oscillation signal.
14. A communication apparatus, comprising:
a frequency synthesizer configured to provide an oscillation signal, including:
a voltage controlled oscillator including a plurality of film bulk acoustic resonators having different resonance frequencies, configured to generate the oscillation signal;
a first frequency divider configured to divide the oscillation signal from the voltage controlled oscillator and to generate a divided oscillation signal;
a second frequency divider configured to divide a reference signal and to generate a divided reference signal;
a phase comparator configured to compare phases of the divided oscillation signal and the divided reference signal and to generate a phase error signal;
a control voltage generator configured to generate a control voltage for the voltage controlled oscillator based on the phase error signal; and
a control circuit configured to generate a control signal based on the control voltage so as to select the film bulk acoustic resonators, and to control an oscillation frequency of the oscillation signal;
a receiver configured to convert a high frequency receiving signal into an intermediate frequency receiving signal by use of the oscillation signal;
a baseband processor configured to demodulate the intermediate frequency receiving signal and to modulate a transmitting signal; and
a transmitter configured to transmit a radio frequency transmitting signal provided by converting the modulated transmitting signal by use of the oscillation signal.
15. The communication apparatus of claim 14, wherein the voltage controlled oscillator comprises:
a resonator configured to resonate with an initial oscillation frequency during a starting period of oscillation and with a steady oscillation frequency during a steady state oscillation, the resonator including one of the film bulk acoustic resonators having a series resonance frequency higher than the steady oscillation frequency; and
a negative resistance circuit connected to each of the film bulk acoustic resonators, configured to drive the resonator, the negative resistance circuit having a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.
16. The communication apparatus of claim 15, wherein the resonator comprises:
a phase adjuster connected to the one of the film bulk acoustic resonators; and
a reactance controller connected to the film bulk acoustic resonator or the phase adjuster, the reactance controller having reactance controlled by the control voltage.
17. The communication apparatus of claim 15, wherein the initial oscillation frequency is in a range higher than the series resonance frequency and lower than a parallel resonance frequency of the one of the film bulk acoustic resonators.
18. The communication apparatus of claim 15, wherein, at the series resonance frequency, a ratio of a maximum reactance difference of a reactance controller in a variable range of the control voltage to reactance of the reactance controller at a center value of the control voltage is in a range larger than 0.5, and a ratio of reactance of the reactance controller at the center value of the control voltage to reactance attributable to an electrostatic capacity of the one of the film bulk acoustic resonators is in a range not less than 0.30 and not more than 1.50.
19. The communication apparatus of claim 18, wherein a ratio of the maximum reactance difference to a difference between a maximum reactance value and a minimum reactance value of the one of the film bulk acoustic resonators is in a range not less than 0.05 and not more than 0.30.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A protection device to protect an electronic apparatus, the protection device comprising:
a motion-detection device, to supply at least one alert signal in response to conditions of motion of the protection device;
a counter;
a first logic circuit, to increment the counter in a presence of a first value of the alert signal, in a first operating condition; and
a second logic circuit, to generate a protection signal on a basis of a count value of the counter;
wherein the first logic circuit is configured to decrement the counter in a presence of a second value of the alert signal, in the first operating condition.
2. The device according to claim 1 wherein the first operating condition is defined by an inactive value of the protection signal.
3. The device according to claim 1 wherein the first logic circuit is configured to increment the counter iteratively by an increment step in the presence of the first value of the alert signal and to decrement the counter iteratively by a decrement step in the presence of the second value of the alert signal, in the first operating condition.
4. The device according to claim 3 wherein the increment step and the decrement step of the counter are programmable.
5. The device according to claim 1 wherein the second logic circuit is configured to switch the protection signal and to reset the counter if the count value has reached a first threshold, in the first operating condition.
6. The device according to claim 1 wherein the first logic circuit is configured to increment the counter in the presence of the second value of the alert signal and to decrement the counter in the presence of the first value of the alert signal, in a second operating condition.
7. The device according to claim 6 wherein the second operating condition is defined by an active value of the protection signal.
8. The device according to claim 6 wherein the second logic circuit is configured to switch the protection signal and to reset the counter if the count value has reached a second threshold, in the second operating condition.
9. The device according to claim 1 wherein the motion-detection device includes:
an inertial sensor, to generate motion signals correlated to conditions of motion of the protection device; and
a processing circuit, coupled to the inertial sensor to supply the alert signal in response to configurations of the motion signals.
10. The device according to claim 9 wherein the inertial sensor is a microelectromechanical sensor.
11. The device according to claim 1 wherein the motion-detection device, the counter, the first logic circuit, and the second logic circuit are housed in a single packaging, provided with a terminal to make the protection signal available externally.
12. An electronic apparatus, comprising:
a microprocessor;
a peripheral unit controlled by the microprocessor; and
a safety device coupled to the microprocessor to supply a protection signal, the safety device including:
a motion-detection device to supply at least one alert signal in response to a condition of motion;
a counter coupled to said motion-detection device;
a first logic circuit coupled to said counter, to increment the counter in response to a first value of the alert signal, in a first operating condition; and
a second logic circuit coupled to said counter, to generate said protection signal based on a count value of the counter;
wherein the first logic circuit is configured to decrement the counter in response to a second value of the alert signal, in the first operating condition.
13. The apparatus according to claim 12 wherein the microprocessor is configured to bring the peripheral unit into a safety configuration, in response to the protection signal.
14. The apparatus of claim 12 wherein the motion-detection device includes:
an inertial sensor, to generate motion signals correlated to said condition of motion; and
a processing circuit, coupled to the inertial sensor to supply the alert signal in response to particular configurations of the motion signals.
15. The apparatus of claim 14 wherein said microprocessor, peripheral unit, and safety device are part of a portable computer, and wherein said inertial sensor and said processing circuit are located on different semiconductor chips of said portable computer.
16. A method for protecting an electronic apparatus, the method comprising:
detecting conditions of motion of the electronic apparatus;
incrementing an index in a presence of the conditions of motion, in a first operating condition;
generating a protection signal on a basis of the index; and
decrementing the index in an absence of the conditions of motion, in the first operating condition.
17. The method according to claim 16 wherein the first operating condition is defined by an inactive value of the protection signal.
18. The method according to claim 16 wherein said incrementing includes incrementing the index iteratively by an increment step and said decrementing includes decrementing the index iteratively by a decrement step, in the first operating condition.
19. The method according to claim 18, further comprising programming the increment step and the decrement step.
20. The method according to claim 16, further comprising switching the protection signal and resetting the index, if the index has reached a first threshold, in the first operating condition.
21. The method according to claim 16, further comprising:
decrementing the index in the presence of the conditions of motion, in a second operating condition; and
incrementing the index in the absence of the conditions of motion, in the second operating condition.
22. The method according to claim 21 wherein the second operating condition is defined by an active value of the protection signal.
23. The method according to claim 22, further comprising switching the protection signal and resetting the index, if the index has reached a second threshold, in the second operating condition.
24. The method according to claim 16 wherein said detecting conditions of motion includes:
using an inertial sensor, to generate motion signals correlated to conditions of motion of the electronic apparatus; and
supplying an alert signal in response to configurations of the motion signals.
25. The method according to claim 24 wherein the alert signal is a free-fall signal.
26. The method according to claim 24 wherein the alert signal is a roll signal.
27. An electronic apparatus, comprising:
means for detecting a condition of motion;
means for changing an index to increment said index in response to detected presence of said condition of motion, in a first operating condition; and
means for generating a protection signal based on a value of the index,
wherein said means for changing decrements the index in response detected absence of said condition of motion, in the first operating condition.
28. The apparatus of claim 27, further comprising:
a microprocessor; and
a peripheral unit controlled by the microprocessor, wherein said processor is adapted to receive said protection signal to place said peripheral unit in a protective configuration.
29. The apparatus of claim 27 wherein said value of the index is a count value of a counter.
30. The apparatus of claim 27 wherein the first operating condition is defined by an inactive value of the protection signal.