RU2289200C2 - Converter of analog signals into time-modulated pulse pattern - Google Patents

Abstract

FIELD: multi-channel systems for converting and transferring information with time multiplexing; communication devices.

SUBSTANCE: converter of analog signals into time-modulated pulse pattern consists of controller, which includes clock pulse generator with quartz stabilization and clock pulse distributor, commutator, analog-digital converter, trigger, AND element, binary counter, time-pulse pattern former, which includes pedestal impulse former and monitoring pulse former, adder, power amplifier.

EFFECT: increased conversion accuracy.

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Description

The invention relates to multi-channel information conversion and transmission systems with time-division multiplexing and can be used in measuring equipment and communication devices.

A device [1] is known, comprising a switch, a controller including a clock generator with quartz stabilization and a clock distributor, a ramp generator, a voltage comparator, a time-pulse shaper, including an adder and reference and pulse shapers, the outputs of which are connected to the inputs of the adder, respectively, whose output is connected to the input of the power amplifier, the first output of the switch is connected to the first the measuring pulse generator, the second output of the switch is connected to the first input of the voltage comparator, the output of which is connected to the second input of the measuring pulse generator, the second output of the clock distributor is connected to the clock input of the switch, the third output of the clock distributor is connected to the input of the ramp generator, output which is connected to the second input of the voltage comparator, the input of the pulse shaper is connected to the first output of the switchgear Ithel clock.

The above device is the closest in technical essence to the claimed device and therefore is selected as a prototype.

The main disadvantage of the device is the relatively low accuracy of converting analog signals to a pulse modulated time-domain sequence, due mainly to the relatively low linearity of the sawtooth voltage (from 10 to 1%) [2].

Achievable technical result is to increase the accuracy of the conversion of analog signals into a pulsed sequence, modulated in time.

The indicated technical result is achieved in that the converter of analog signals into a time-modulated pulse sequence comprises a switch, a controller including serially connected clock oscillator with quartz stabilization and a clock distributor, a pulse train shaper, including an adder and reference and measuring pulse shapers, the outputs of which are connected to the inputs of the adder, respectively, the output of which is connected to the input of the amplifier Ithel power, the first output of the switch connected to the first input of the measuring pulses, the reference pulse generator input coupled to the first output clock distributor. What is new is that a binary counter, a trigger, an AND logic element, an analog-to-digital converter (ADC) are introduced, the second output of the switch is connected to the analog input of the ADC, the digital outputs of which are connected to the inputs of the binary counter, respectively, the starting input of the ADC is connected to the second the output of the clock distributor, and the ADC data availability output is connected to the clock input of the switch and the input input of parallel loading of the binary counter, the output of which is connected to the second input of the measuring driver x pulses and the first input of the trigger, the second input of which is connected to the third output of the clock distributor, and the output is connected to the first input of the logic element "I", the second input of which is connected to the second output of the clock with quartz stabilization, and the output is connected to the counting input binary counter.

The specified set of features allows to increase the accuracy of the conversion of analog signals into a time-modulated pulse sequence by introducing a n-bit analog-to-digital converter (ADC) and n-bit binary counter instead of a linearly varying voltage generator and voltage comparator.

The figure 1 shows a diagram of the proposed device. The figure 2 shows a timing diagram of the Converter of analog signals into a pulse sequence, modulated in time, where

t _CR - the conversion time of the ADC,

t _NZI , t _take - respectively the lower and upper protective intervals,

t _ISM - measured interval,

t _{meas. min} , t _{meas. max} - respectively the minimum and maximum measured interval,

t _{meas. max} -t _{meas. min} - permissible change in the measured interval.

The converter of analog signals into a time-modulated pulse sequence comprises a controller 1, including a series-connected clock with a quartz stabilization 2 and a clock distributor 3, switch 4, analog-to-digital converter 5, trigger 6, logic element "I" 7, binary counter 8, the shaper of the time-pulse sequence 9, including the shapers of the reference 10 and the measuring pulses 11 and the adder 12, the power amplifier 13.

The analog input of the ADC 5 is connected to the second output of the analog switch 4, the digital outputs of the ADC 5, the signals of which together form a digital code, are connected to the corresponding DI inputs of the binary counters 8, providing parallel asynchronous download of the binary digital code, the data readiness output of the ADC 5 is connected to the clock the input of the switch 4 and the control input of the parallel load of the binary counter 8, the transfer output of the RD of the previous counter is connected to the counting input of the LED of the subsequent counter, the output of the RD of the last counter and connected to the second input of the shaper of the measuring pulse 11 and the first input of the trigger 6, the second input of which is connected to the third output of the clock distributor 3, and the output of the trigger 6 is connected to the first input of the logic element "And" 7, the second input of which is connected to the second output of the generator clock frequency with quartz stabilization 2, and the output of the logic element "And" 7 is connected to the counting input of the binary counter 8. The output of the clock generator 2 is connected to the input of the clock distributor 3, the second output to otorochno connected to the input of the ADC 5. The first output of the switch 4 is connected to the first input of the pulse shaper 11, the input of the pulse shaper 10 is connected to the first output of the clock distributor 3, the outputs of the pulse shaper 10 and the pulse shaper 11 are connected to the inputs of the adder 12 respectively, the output of which is connected to the input of the power amplifier 13.

The converter of analog signals into a pulsed sequence, modulated in time, works as follows.

When a pulse is received at the input of the ADC 5, a cycle begins of converting the AIM signal that is installed on the analog input into an n-bit digital code, after which the “Data Ready” pulse from the output of the ADC 5 performs its asynchronous parallel download to binary counter 8 and switches the analog switch 4 for forming the AIM signal of the next sensor (channel).

After the formation of the reference pulse after a minimum time t _min , determined by the resolving power of the transceiver and recording systems, the controller 1 generates a pulse synchronized with the clock frequency, which sets the trigger 6 to the logical unit position, thereby allowing the clock pulses to pass through the logic element "And" 7 on counting input binary counter 8, working on subtraction. When the counter 8 passes through zero, an overflow appears on the counter overflow 8 output, which is input to the shaper of the measuring pulse 11. The appearance time of this pulse relative to the reference pulse is proportional to the signal value at the analog input of the ADC 5.

The measuring pulse, in addition, closes the key, stopping the arrival of clock pulses to the counters 8 and thereby ensuring a single occurrence of the measuring pulse in the measured interval.

The conversion error Analog - VIM in the proposed device consists of:

1. From the error of conversion of an analog to a digital code (error of the selected ADC) δ _ADC .

2. From the conversion error of the digital code into the time interval δ _INT .

In modern ADCs using special sampling and storage devices that ensure the input voltage is constant for the conversion time, the maximum conversion error does not exceed one or two units of the least significant bit (3) and is

where: n is the resolution of the output digital code of the ADC;

at n = 10, δ _ADC = (0.1 ÷ 0.2)%

Considering that the beginning and end of the measured time interval are synchronized with the clock pulses filling the interval, the error δ _INT is due only to the time instability of the clock frequency. For oscillators stabilized by quartz, this instability does not exceed 5 * 10 ^-5 (0.005%) [4] and, therefore, it can be neglected in comparison with δ _ADC .

Thus, the description of the work shows that the inventive Converter allows you to increase the accuracy of the conversion of analog signals into a pulsed sequence, modulated in time.

In order to confirm the feasibility of the claimed object and to achieve a technical result, a laboratory prototype of the converter of analog signals into a pulse sequence, modulated in time, made according to the diagram shown in figure 1, was made and tested. The tests showed the feasibility of the inventive Converter and confirmed its practical value.

Information sources

1. Collection of reports of the scientific conference of the Volga regional center RARAN "Modern methods of design and development of missile and artillery weapons", published, Sarov, VNIIEF, 2000

2. V. A. Bondar, "Generators of linearly varying voltage", Moscow, Energoatomizdat, 1988

3. E.I. Gitis, E. A. Piskulov, "Analog-digital transducers", Moscow, Energoizdat, 1981

4. Collection of information sheets "Piezoelectric devices", RD 11 0955.1-96, RNII "Electrostandard", 1997

Claims (1)

A converter of analog signals into a time-modulated pulse sequence containing a switch, a controller including serially connected clock oscillator with quartz stabilization and a clock distributor, a time-pulse generator, including an adder and reference and measuring pulse generators, the outputs of which are connected to the inputs the adder, respectively, whose output is connected to the input of the power amplifier, the first output of the switch is connected with the first input of the measuring pulse generator, the input of the reference pulse generator is connected to the first output of the clock distributor, characterized in that a binary counter, a trigger, an AND logic element, an analog-to-digital converter (ADC) are additionally introduced, the second output of the switch is connected to an analog the ADC input, the digital outputs of which are connected to the inputs of the binary counter, respectively, the ADC start-up input is connected to the second output of the clock distributor, and the data readiness output is the AD connected to the clock input of the switch and the parallel boot control input of the binary counter, the output of which is connected to the second input of the measuring pulse generator and the first trigger input, the second input of which is connected to the third output of the clock distributor, and the output is connected to the first input of the AND gate, the second input of which is connected to the second output of the clock generator with quartz stabilization, and the output is connected to the counting input of the binary counter.

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