SU1187256A1 - Synchronizing device - Google Patents

Description

The invention relates to a pulse technique and can be used in radio measuring devices, for example, in oscillography and automatic meters of the parameters of 5 meters of pulse signals.

The aim of the invention is to improve the reliability of the device.

FIG. 1 shows a block diagram of a synchronization device; 10 in FIG. 2 - time diagrams when the device operates at high frequency.

The device contains an amplifier 1 connected by an input to an input bus 15 2 of the device, and an output to the first inputs of the first and second elements I 3 and 4 and through the first delay element 5 to the second inputs of these elements, the third inputs connected 20 to the input of the second delay element 6 , inverse and direct outputs connected respectively to the fourth inputs of the second element I 4 and the first element I 3, output 25

connected through the third delay element 7 with the first input of the third element AND 8, the output connected to the input of the driver 9, the first and second outputs connected respectively to the output bus 10 of the device and the input of the one-shot 11, as well as an additional one-shot 12, additional delay element 13 , element OR-NOT 14 and trigger 15, zero input connected to the output of the second element 4, and single input and output, respectively, with the first and second inputs of the third element 8, the output of the one-shot 11 connected to the input Tel'nykh monostable multivibrator 12 and via an additional delay element .13 to a first input of OR-NO element 14, the second and third inputs connected respectively to the input and output ground additional monostable multivibrator, and an output of OR-NO element 14 is connected to the input of the second delay member 6.

The device works as follows.

The synchronization pulse from the input bus 2 enters the input of the amplifier 1, where it is amplified to the value,; 55

sufficient for the operation of subsequent elements, is fed to the first inputs of the first 3 and second 4 elements I. The other inputs of these elements receive signals from the outputs of the first delay element 5, the second delay element 6 and the element OR NOT 14.

The parameters of the second delay element 6 are selected so that the delay of the signal from the output of the OR-NO 14 element at its inverse output (b _a ) is about two times greater than the delay at the direct output (b)).

The delay of the clock signal in the first delay element 5 is taken close to and its output signal is inverted.

The synchronizing signal passes to the output of the first 3 and second 4 elements And only with the simultaneous appearance at their inputs of signals of the logic level "1".

Consider the operation of the device from the moment when the output voltage of the OR-NO 14 element appears negative voltage drop (from the logic level "1" to the logic level "0"), corresponding to the front of the output negative pulse from it ·.

This differential, arriving at the third inputs of the first 3 and second 4 elements And, prohibits the passage through them of the clock pulse coming from the output of the amplifier 1 to their first inputs.

The ban continues for a time equal to the pulse duration from the element OR NOT 14, and there is no signal at the device output.

At the end of the pulse from the element OR-NOT 14, a positive voltage drop occurs from its output (from the logic level "0" to the logic level "1"), thereby removing the prohibition acting on the third inputs of the first 3 and second 4 elements I.

The passage of the synchronizing pulse to the output of these elements now depends on the ratio of the delayed signals acting on their first, second and fourth inputs and taken from the first 5 and second 6 delay elements.

The conditions for the passage of a pulse through the first element I 3 are as follows.

Allowing a positive differential from the direct output of the second element 6 of the delay arrives at its fourth input some time after

3

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the appearance of a positive differential at the third input. Therefore, the resolution of the signal passing through the element And 3 begins with a point in time.

Depending on the moment of arrival of the synchronizing pulse at the first input and the moment of receipt of the enabling positive differential at the third input of the first element And 3, the following two cases are possible.

If the sync pulse arrives after the arrival of the resolution differential, the output of the first element I 3 passes a part of the clock pulse, equal in duration to the delay on the first delay element 5, since with each clock pulse coming from the output of amplifier 1 to the first input of the And 3 element, after a time equal to the delay of the pulse at the first delay element 5, an inverted clock pulse arrives at the second input of the element 3 and is prohibiting for a part of the clock pulse lsa, acting at the first input.

If the synchronizing pulse arrives at the moment of the arrival of the differential, the output of the first element And 3 passes some part of this pulse, determined by the location of its front in relation to the enabling differential from the output of the element OR NOT 14. If the arrival of the next synchronizing pulse if the differential is over, the subsequent pulses in accordance with the first case pass to the output undistorted. In the second case, the first of the output pulses is distorted, and the subsequent ones are undistorted.

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This distorted pulse must be excluded from the number of devices passed to the output, because, due to the instability of the frequency of the synchronizing signal and the instability of the pulse duration from the output of the OR-NOT 14 element, the conditions for the passage of the pulse to the output of the first element I 3 from the beat to the clock cycle can be both corresponding to the first case and the second one. This means that the first impulse can be both undistorted and distorted, which leads to a temporary

pulse instability at the output of the device.

The conditions for passing the signal through the second element And 4 follow e.

After receipt, it is allowed: a positive differential drop to the third input of this element from the output of the element OR NOT 14 after some time

its fourth input from the inverse motion of the second element 6 of the delay enters a deny denying differential. Thus the second AND gate 4 formed hydrochloric time zone ^"within which the discharge passage etsya clock pulse at its output. The beginning is ahead of the resolving difference of the third input of the first element by the amount C, and the end is behind the

20 for the same value.

Zone _{2 is} used to control the fact that the pulse at the output of the first EI 3 can be distorted, since the synchronizing pulse coincides with this zone about the possibility of coinciding e by the resolution difference at the input of the element, and therefore, the claim coinciding with the difference of the output pulse .

The synchronizing pulse p payus on the first and second input of the second element And 4, coinciding v:

with the zone passes on his

Contact with the synchronizing zone at the boundaries of the zone leads to shortening (distortion).

The circuit composed of the first element AND 3 and the third delay element forms the main circuit of the transmission of the synchronizing impulse circuit, composed of the second element AND 4 and the trigger 15, on the auxiliary channel.

The third element And 8 org prohibits the impulses of the auxiliary channel pulses of the main channel.

If the synchronizing impulse falls in the zone £ _g , then any impulse in the main channel is considered to be expired and should be prohibited. It is forbidden by a signal from a trigger which enters the input of a tert element AND 8 level logical from a single trigger output.

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the inputs of the third element And 8. Alignment is necessary to exclude

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banning signals of the main channel.

With the advent of a pulse at the output of the second element I 4, a trigger 15 is cocked on its front. As a result, a logic level “O” signal appears at its single output, which prohibits the passage of pulses of the main channel through the third element 8.

By the cut of the main channel pulse, the flip-flop of the trigger 15 is reset to the initial state, in which the logical level “1” appears at the direct output, which leads to the lifting of the ban on the third element E 8. The ban is lifted after a time equal to the trigger switching delay 15. If the auxiliary channel does not receive the impulse again, which translates the trigger 15 into the state of a logical "O" at the single output, then the next impulse of the main channel passes to the output of the third element 8. If an impulse appears in the auxiliary channel s, the situation with the main channel and umklapp pulse prohibition of slice pulse of trigger channel 15 is repeated.

The repetition occurs until the synchronizing impulse leaves the zone ^{and the} impulse following the last impulse of the main channel, triggering trigger 15, passes to the output of the third element And 8. This impulse is not distorted, because the transient processes associated with the formation of a cutoff impulse with element-or-not 14 finished.

Consider the situation when a synchronizing pulse hits the boundaries of zone b ₂ . Since these boundary values correspond either to the absence of a permissive differential in the main channel (the beginning of the zone) or to an end transition process corresponding to the permissive differential (end of the zone), the unstable operation of the auxiliary channel at the boundaries of the zone does not lead to a temporary instability of the pulse from the output of the device. This is because at the beginning of the zone a pulse in the main channel is still missing, and the end of the zone corresponds to an undistorted pulse in the main channel, which is either passed to the output (if the switch does not flip trigger 15) or not passed (when the trigger is switched 15), but then the device passes the next sync pulse, which is back to the right of the zone and is uncorrupted.

Thus, thanks to the auxiliary channel and the presence of a zone, the impulse from the output of the third element And 8 is always undistorted. This impulse starts the shaper 9 pulses, which sends a sync pulse to the output bus 10 of the device, and also issues a positive one-shot 11 start pulse, lasting, more than double the start delay of this one-shot from the second output. On the front of the pulse from the shaper 9 through the third input of the element OR NOT 14 to the third inputs of the first 3 and second 4 elements And a level difference of logical "O" is received, which prohibits the signal from passing through these elements I. At the same time, the one-shot 11 starts up, a positive impulse arrives at the launch of the one-shot 12, through the cut of which it starts and through the delay element 13 to the first input of the element OR NOT 14 To the second input of this element comes an output positive pulse from the output of the one-shot 12.

In the OR-NOT 14 element, a logical addition and inversion of the signals received at its inputs occurs; as a result, a logic level "0" signal is produced at its output and the duration from the moment of appearance of the front of the pulse from shaper 9 to the moment of appearance of the cutoff of the pulse from the single vibrator 12, those. approximately equal to the sum of the durations of the pulses of one-shot 11 and 12.

The cycle of formation of the next output clock begins with the moment when the signal of the logic level “1” appears at the output of the OR-NOT 14 element, since the end of the formation of a pulse in the one-shot 12. By this time, the one-shot 11, which is in recovery mode for a duration of 7

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pulse from the one-shot 12, the recovery-related processes are completed, and it is ready to start with the next pulse from the former 9. The one-shot 12 is restored during the duration of the pulse from the one-shot 11. It is advisable to generate pulses of the same duration from one-shot, then in the worst case when the device operates at high frequency, the single vibrators operate with a duty cycle of at least two, which is the usual one-shot mode.

The repetition period of the clock pulses on the output bus 10 with an arbitrary value of the period of the signal on the input bus 2 cannot be less than the sum of the durations of the pulses from the single-oscillators 11 and 12.

¹ The period of the signal entering the device (figure 2) is taken as smaller than the C ₂ zone, which corresponds, for example, to frequencies of hundreds of megahertz, since the zone is easy to provide in units of nanoseconds.

The clock signal arriving at the input bus 2 is normalized by amplitude in amplifier 1, delayed by the value, inverted in the first delay element 5 and fed to the first 3 AND; the second 4 I.

With the advent of the permissible differential from the logical "0" to the logical "Ι" from the output of the element OR NOT 14 and re- _; pads from the outputs of the second delay element 6-formed interval b | and the zone ^and the transmission of pulses to the main and auxiliary channels begins.

The first impulse of the main channel (element 3), which appeared after the arrival of the enabling differential (element 6 is straight, the differential is marked with hatching), is distorted because it falls on this differential (left side of the diagram), or it will be distorted as it appears to the right of the differential ( right side of the diagram). In any case, it is located in zone C ₂ , and therefore is subject to a ban.

The first impulse of the auxiliary channel (element 4) cocks the trigger

15, which blocks the third element And 8. The second impulse of the auxiliary channel confirms the weighted state of the trigger 15. The trigger 15 is shifted by cutting the pulse of the main channel delayed by the third delay element 7 (elements 7 and 15). However, in the left part of the diagram, the signal has not yet left the zone, and therefore the third pulse is again triggered by the third pulse of the auxiliary channel, and a cut of the corresponding pulse of the main channel. This trigger returns to its original state, which allows the signal to pass through the third element 8. Another pulse the main channel passes to the output of this element, and on its front, the driver 9 starts up with a delay, from the first output of which a pulse is outputted to the output bus 10, which is the output signal of the device, with the second output - to start odnovib Rhatore 11 i.elementa NOR 14. Od novibrator 11 runs with delayed Coy and generates a pulse of a duration of a slice for which

hold one-time running

12 and generates a pulse duration

The impulse from the one-shot output 11 is delayed by the element 13 of the stop by the value 6 ^ 13 · These signals are collected on the element OR NOT 1 and provide a signal level of a logical "0" and the output of this element in the time interval from the response of the driver 9 to pulse cut from the output of the one-shot 12 than the first 3 and second 4 elements I are blocked at this time. The minimum repetition period of the synchronization pulses T _c on the output bus 10 is determined by the ratio

^t with ⁼ * -ei ^{+ g} and <1 ⁺ Ch'g ⁺ , ¹ "'??

On the output bus 10 device

a pulse of constant duration, determined by the shaper 9, and tied to an undistorted input synchronizing pulse (shaded pulse in the diagram, element 1) is formed.

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Claims (1)

A SYNCHRONIZING DEVICE containing an amplifier whose input is connected to the input bus and the output is connected to the first inputs of the first and second And elements and through the first delay element to the second inputs of these elements, the third inputs of which are connected to the input of the second delay element, the inverse and direct outputs of which connected respectively to the fourth inputs of the second and first elements And, the output of the last of which is connected through the third delay element with the first the input of the third element And, output, which is connected to the input form; pulse generator, the first and second outputs of which are connected respectively with the output bus and the input one-shot one-shot, characterized in that, in order to increase reliability, put it into it; > we have an additional one-shot and delay element, an OR-NOT trigger element, whose zero input is spedin with the output of the second AND element, and a single input and output are connected to the first and second inputs of the third AND element, respectively, when: the output of the main one-shot is connected to the input additional ((the new vibrator and through an additional delay element with the first input of the OR-NOT element), the second and third inputs of which are connected respectively to the main input and the output of the additional single-oscillators, g the output of the OR-NOT element is connected to ode second delay element. about h with with I 1187256