摘要:
PROBLEM TO BE SOLVED: To provide an oscillation circuit that can improve accuracy of an oscillation frequency.SOLUTION: The oscillation circuit comprises: a reference voltage generation circuit that adds and outputs a PTAT output and a CTAT output; a first switch means that switches an addition ratio to minimize output voltage fluctuations of the temperature-dependent reference voltage generation circuit; a current source that generates a constant current based on the output voltage of the reference voltage generation circuit; a regulator circuit that generates a constant voltage based on the output voltage of the reference voltage generation circuit; a first capacitance and a second capacitance whose one end is connected to the current source to be charged and discharged by the constant current of the current source; an inverter that drives the other end of the second capacitance by the use of the constant voltage supplied from the regulator circuit as a power source; a second switch means that switches the constant current value of the current source to trim an oscillation frequency; and a third switch means that switches the capacitance value of the first capacitance to trim an oscillation amplitude at the one end of the first capacitance and the second capacitance. The oscillation circuit generates a desired amount of constant frequency by trimming with the first switch means, the second switch means, and the third switch means.
摘要:
PROBLEM TO BE SOLVED: To prevent jitter of an output signal of a transmission device. SOLUTION: The transmission device includes: an input signal disconnection detection unit that detects whether the input signal is input; an oscillator; and a frequency setting unit that sets oscillating frequency of the oscillator so that a difference frequency between the oscillating frequency of the oscillator and a frequency of a dividing signal that divides a clock signal extracted from the input signal is out of passband of a filter when the input signal detection unit detects that the input signal is input. COPYRIGHT: (C)2011,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide an oscillator capable of providing signals of stable oscillation periods. SOLUTION: The oscillator has a plurality of logic devices connected in a ring form and operates with a variable driving voltage to provide an oscillation signal of a predetermined period. The oscillator includes an internal voltage generating means for generating first and second driving voltages to be applied selectively to the plurality of logic devices; and when the period of the oscillation signal is in a normal state, then the first driving voltage is applied to the plurality of logic devices; when the period of the oscillation signal is shorter or longer than the normal state, then the second driving voltage VOSC is applied to the plurality of logic devices; and thus the oscillator is configured to maintain the period of the oscillation signal constant. COPYRIGHT: (C)2011,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide an oscillator that generates an output signal having a rising time corresponding to electronic equipment containing the oscillator, and thus generate the output signal with high accuracy. SOLUTION: The oscillator includes: a waveform shaping section 300 having a plurality of waveform shaping circuits 500A to 500C for differently shaping the waveforms of intermediate output signals output from an oscillating section 200; a storage 400 for storing data corresponding to a waveform shaping circuit 500 selected from the waveform shaping circuits 500A to 500C; and a control section 450 that causes the waveform shaping circuit 500 selected from the waveform shaping circuits 500A to 500C contained in the waveform shaping section 300 to shape the waveform of the intermediate output signal based on the data stored in the storage 400. COPYRIGHT: (C)2010,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide a squelch detection circuit capable of resisting variation in temperature, processes and power supply voltage and capable of outputting a stable squelch detection signal. SOLUTION: The squelch detection circuit includes a peak detection circuit 11 for outputting a detection signal Vp as a pulse when the potential amplitude of received differential signals RX+, RX- exceeds a prescribed value and a pulse width extension circuit 12 for extending the pulse width of the detection signal Vp output from the peak detection circuit 11 at least by one period of the differential signals RX+, RX-. The peak detection circuit 11 includes: an input differential amplification circuit 11A for outputting a voltage signal Vdata corresponding to a difference of biased differential signals after applying the same DC bias to the differential signals RX+, RX-; a replica reference voltage generation circuit 11B configured almost as a replica circuit of the input differential amplification circuit 11A to output a shift reference voltage Vref obtained by level-shifting a reference voltage Vref'; and a voltage comparator 11C for comparing the voltage signal Vdata with the shift reference voltage Vref and outputting a detection signal Vp. COPYRIGHT: (C)2010,JPO&INPIT