Nous commençons notre étude par celle des bascules, éléments de base des circuits A partir de ce chronogramme nous pouvons écrire la liste des états. Read the latest magazines about Chronogramme and discover magazines on Embed Share. les bascules bistables – · Download scientific diagram | Chronogramme des tensions appliquées à un PMOS Résultats de la mesure transitoire pour la chaine de bascules D sans.
|Published (Last):||4 March 2005|
|PDF File Size:||14.29 Mb|
|ePub File Size:||3.11 Mb|
|Price:||Free* [*Free Regsitration Required]|
Kind code of ref document: Country of ref document: Date of ref document: Year of fee payment: We already know many frequency divider circuits. Most use a phase locked loop, commonly called PLL abbreviation of the English name phase locked loop.
EP0218512B1 – Digital frequency divider circuit – Google Patents
The recovered frequency signal f is applied to a divider by three 10 whose output is connected to one input of a phase comparator The error signal provided by the comparator 12 is subjected to low pass filtering in a filter 14 for picking up the phase error signal. This error signal is applied to a voltage controlled oscillator or VCO Such a circuit to phase-locked loop has disadvantages. Analog components used are expensive, difficult to integrate large-scale on silicon together with digital components, sensitive to noise and temperature variations.
These disadvantages are particularly serious for consumer applications such as television receivers. The operating range is limited to a frequency band around a nominal value. The catching time during which the output signal is not usable, is noticeable, which is even more annoying than the operating frequency is high, and this time is higher as we wants to have a wide operating band.
This known ring counter makes it possible to obtainfrom a master clock signal at frequency f, at least one lower frequency rectangular signal. Toutes les bascules du compteur sont identiques. All flip-flops of the counter are identical. It is necessary to have not only a clock but also the complementary logic signal. The invention aims to provide a simple frequency divider circuit, fully digital, so integrated, not requiring to generate additional clock signal.
For this purpose, the invention provides a digital circuit in accordance with the characterizing part of claim 1.
Such a circuit is insensitive to differences in speed between the logical components adaptable to the fractional frequency generating M being different from 1 as well as that of several reduced frequency chrinogramme, phase shifted relative to each other. The invention will be better understood from reading the following description of a particular embodiment, given by way of example. The description referenc to the accompanying drawings, wherein: Plusieurs constitutions des bascules sont possibles.
Several constitutions flops are possible. Use may in particular constitutions and bonds shown in Figure 3 and 4 for circuits made of transistors “NMOS enriched and depleted. Figure 3 shows a flip-flop xhronogramme B 2n and connections are identified correspondingly, 2n can baxcules the values 0, 2 and 4.
In all cases the indices carried on the inputs and outputs must be considered modulo 6.
EPB1 – Digital frequency divider circuit – Google Patents
The flip-flops have all the same heart, typically consisting of four C-MOS transistors connected in pairs in series, with two crossed gate-drain couplings. H and X inputs of flip-flop receiving the clock signal H and the output Q of flip-flop B 2n. More generally, we can use flip-flops whose truth tables are those given in Figures 5 and 6 of the request. The source of all the transistors 38 is connected to ground chgonogramme the gates are driven in parallel by the initialisation signal I.
For all other scales, the drain of transistor 38 is connected to the output Q. The circuit operation is as follows, when it receives clock pulses cnronogramme H frequency.
An initialization phase is necessary, in which the I signal must remain at logic level 1 long enough to force the state of all the latches. B0 latch is forced to the state other latches are forced to 0.
At the end of initialization, the first rising edge of clock that is to say when the signal H changes from 0 to 1 at time t0 in Figure 7Q0 returns to 0 and Q1 goes to 1.
Other arrangements would provide different frequencies. Successive signals can be used for decoding addresses sequentially: It is sufficient to chronogrzmme only the outputs Q of the odd flip-flops for time intervals equal to the duration of a drive pulse between successive pulses. Using storage elements with multiple chronogrammme values to reduce supply current spikes in digital circuits. Programmable digital clock signal frequency divider module and modular divider circuit.
Chronogdamme digital detector for the demodulation of angle modulated electrical signals. System for synchronous data transmission with the aid of a constant envelope amplitude-modulated carrier.
Modulator-demodulator for four level double amplitude modulation ds quadrature carriers. A1 Designated state s: Lapsed in a contracting state announced via postgrant inform. IT Free format text: B1 Designated state s: DE Date of ref document: DE Free format text: