摘要:
A circuit device for neutralizing thermal drift in a transconductor differential stage using a first circuit portion which corresponds structurally to the transconductor differential stage and has a pair of MOS input transistors defining a transconductance value which is substantially proportional to that of the transconductor differential stage, a pair of bipolar output transistors coupled to the MOS input transistors in a cascode configuration, and a second circuit portion being supplied a current from an output of the first differential portion to thereby output a current to be passed to the transconductor differential stage. The value of the output current is inversely proportional to temperature-dependent parameters of the transconductance.
摘要:
A circuit device for phasing an oscillator, which comprises a multivibrator having a transistor pair with the emitters coupled through a capacitor, comprises a normally open electronic switch controlled by a drive signal to close and inhibit the oscillator. This switch connects a voltage divider to the base of a transistor connected to one of the emitters to interrupt the loop positive feedback of the oscillator upon the voltage across the capacitor reaching a predetermined value.
摘要:
The tristate output gate structure particularly for CMOS integrated circuits, comprises an enable terminal receiving an enable signal and an input terminal receiving an input signal, which connects, through signal switching means, an output terminal to a positive power supply terminal or to a negative power supply terminal. The enable terminal can be electrically connected to the gate terminal of a first P-channel transistor through signal inverting means and to the gate terminal of a second N-channel transistor. The output terminal is electrically connected to the drain terminals of the first and second transistors. The first and second transistors electrically insulate the output terminal from the input terminal.
摘要:
The circuit structure comprises a series of storage units, a data bus, an address bus, a line for a reading/writing signal, a precharge logic suitable for precharging the address bus with a precharge address and a precharge sensor suitable for enabling the operation of address decoders of the storage units with a given delay with respect to the end of the precharge. The structure also comprises a flip-flop for controlling the address buses and the precharge logic as well as a delay circuit capable of producing a stop-writing signal with a delay calculated on the basis of the time necessary for the writing of a datum in a storage register of the storage units.
摘要:
A control circuit for an oscillator comprising a multivibrator with transistors having their emitters connected in common and being supplied corresponding currents on respective legs, comprises a circuit structure adapted to produce on output terminals, on the one side, a current which is proportional to a reference current according to a predetermined parameter, and on the other side, a second current in turn correlated to the reference current as a function of said parameter, thereby to modify the oscillator duty cycle for a given operating frequency.
摘要:
A method of automatically measuring the horizontal scan frequency of a composite synchronism signal, comprising horizontal synchronization impulses at line frequency, consists of first performing a count of a number of impulses having a repeat frequency higher than said line frequency, as intervening between two successive impulses at line frequency.The count value, corresponding to said number of impulses, is stored to obtain the line frequency of the signal, and thereafter, a series of down counts is effected, as initiated at predetermined times, until a change of frequency of the signal is detected.
摘要:
A method of automatically measuring the horizontal scan frequency of a composite synchronism signal, comprising horizontal synchronization impulses at line frequency, consists of first performing a count of a number of impulses having a repeat frequency higher than said line frequency, as intervening between two successive impulses at line frequency.The count value, corresponding to said number of impulses, is stored to obtain the line frequency of the signal, and thereafter, a series of down counts is effected, as initiated at predetermined times, until a change of frequency of the signal is detected.
摘要:
In a dynamic automatic loop for control of the overall gain of an input circuit of a superheterodyne receiver, the response time of the HF-AGC circuit of the TUNER, in response to the action of the TUNER DELAY circuit activated by the IF-AGC in the case of autonomously uncontrollable abrupt increases in the level of the antenna signal from the same HF-AGC of the TUNER, is markedly reduced using an additional TUNER DELAY PLUS circuit able to absorb for a determined interval of time, a discharge current from the storage capacitor the control voltage of the HF-AGC in addition to the discharge current absorbed by the existing TUNER DELAY circuit. The relevant intensity of this additional discharge current and its duration are optimized by way of suitable circuital arrangements in the design of said TUNER DELAY PLUS circuit. The response time is reduced without modifying the time constant of the HF-AGC, which cannot be freely reduced because of inter- and cross-modulation problems.
摘要:
A method of demodulating multi-standard TV signals consists of providing a plurality of signals at a frequency which is a multiple of a reference frequency whose value is a common submultiple of the frequencies of the multi-standard signals. Thereafter, the signal to be demodulated is multiplied by one of said plural signals having a frequency which differs therefrom by a value equal to the reference frequency; by filtering the result of the multiplication, a signal is obtained at the reference frequency but corresponding in amplitude to the one to be demodulated.
摘要:
An integrated electronic circuit includes a plurality of active circuits connected together in cascade. A feedback loop is between an output of a last active circuit and an input of a first active circuit so that the plurality of active devices function as a non-linear device, such as an inductor. The integrated electronic circuit may be integrated or used in association with a circuit network including other non-linear devices.