SU1635223A1 - Device for control of aperture time of analog memory unit - Google Patents

Abstract

The invention relates to a measurement technique and may be used in measuring parameters of an analog memory. The aim of the invention is to simplify the device and the process of monitoring the aperture time of analog memory. The goal is achieved by the fact that the aperture time control device of the analog memory contains fast and slow linearly rising voltage generators, a comparator, a reference voltage driver, and an amplifier, the information from which is fed to the oscilloscope vertical deflection input. 5 il.

Description

The invention relates to a measurement technique and can be used in measuring parameters of sampling and storage devices, usually used at the input of analog-to-digital converters.

The aim of the invention is to simplify the device and the process of controlling the aperture time.

FIG. 1 shows a block diagram of the device; in fig. 2 - stress diagrams in the main units of the device; in fig. 3 shows the impulse response of the sampling and storing unit of the analog signal observed on the oscilloscope screen; FIG. 4, 5 — schemes of fast and slow linearly increasing voltage generators and a reference differential generator.

FIG. 1-5 have been entered: 1 pulse generator, delay unit 2, fast ramp voltage generator 3, slow ramp voltage generator 4, comparator 5, one-shot 6, shaper 7 of the reference differential, element AND 8, amplifier 9, oscilloscope 10 , divider 11 frequency by two. the output 12 of the reference differential voltage of the device, the 13 access to the analog memory block of the device, the analog input 14 of the device, the 15 analog block of memory, the analog input 16 of the block, the input 17 controls the operation of the block 15, the analog output 18 of the block 15.

The device works as follows.

The block 15 to be investigated is connected via analog input 16 to the output 12 of the device, via input 17 to the second output 13. The output 18 of the block 15 is connected to the input 14 of the device.

At the output of generator 1, clock pulses are generated with a frequency of FT. From divider 11, impulses with a frequency of FT / Z and a duration longer than 1 are received at the input of the former 7 of the reference differential.

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at the output of shaper 7, a pulse voltage is formed, similar to the input signal, but with sharp fronts (the length of the fronts is obviously less than the estimated aperture time) and amplitude of the order of 1 mV (Fig. 2d). This voltage is applied to the analog input 16 of block 15. Simultaneously, the inputs of generators 3 and 4 receive pulses from generator 1. Using a comparator 5 and a single vibrator 6, a sequence of sampling pulses with a frequency FT and a nominal duration equal to the sampling time is organized at the output of the latter. block 15, shifted in phase relative to the clock signals (Fig. 2c). The phase of the sampling pulses relative to the input differential of block 15 varies linearly with time according to the law of change of the slow saw (Fig. 26). The voltage of the slow saw is fed from the output of block 4 to the input X of the oscilloscope 10 as a horizontal sweep voltage, i.e. provided is directly proportional to the relationship between the horizontal oscilloscope beam deflection and the phase shift of the sample pulse relative to the input signal of block 15. The phase shift range of the sampling pulse is determined by comparator 5 in accordance with the voltage rise rate from the outputs of the generators 3 and 4.

Thus, a smooth shift of the front of the sampling pulse of nominal duration (in this case, the rear one) is organized, according to which unit 15 is transferred to the storage mode relative to the input differential of unit 15. At the same time, every second sampling pulse necessarily selects a constant input voltage (in this case of the lower flat part of the input pulses), ensuring the establishment of the block 15 in the inbound state. As a result, a number of constant voltage levels are formed at the output 18 at a frequency equal to the frequency of the sampling pulses. The values of the lower voltage levels at the output 18 are the same and correspond to the value of the lower level of the input pulse voltage of block 15 (initial state). At the same time, the upper voltage levels at output 18 will have different values depending on the time shift between strobe pulses for storage and the differential analog input signal of block 15. i.e. this shift determines the degree of undercharge of the storage capacitor in block 15. Amplifier-limiter 9 is used to increase the sensitivity, oscilloscope

fa 10. With block 2, the signal from the output of the one-shot b is delayed relative to the strobe pulse of block 15. A pulse of a certain duration is generated at the output of block 2. Element And 8 is used to reduce the frequency of the pulses at the output of unit 2 by half. This selects a pulse that coincides with the signal at output 12 (Fig. 2e). Modulier

0 by the brightness of the oscilloscope beam 10 using light pulses from the output of the element And 8, following with a frequency of FT / 2 and delayed relative to the working pulses of the sample at the time of setting the output signal

5 of the block 15 in the storage mode (ryxp), on the oscilloscope screen, we obtain an exact copy of the image of the response of the block 15 to a small ideal voltage jump, i.e. impulse transient response (Fig. 3). Aperture time is defined as the width of the impulse response at a given level (Fig. 3), i.e. The aperture time is understood as the time interval within which the input level of the small level is averaged during the formation of the output signal of the block 15.

Using the device will allow simple means to measure the aperture

0 block 15 time is right on the oscilloscope grid, which greatly simplifies the device and reduces the time required for the measurement procedure, compared to the prototype device by at least 5 times.

The introduced blocks are structurally simple and widely used in various electronic devices.

Claims (1)

Invention Formula 0 The aperture time control unit of the analog memory block, comprising a pulse generator, a delay unit, and an AND element characterized in that. that in order to simplify the device, it contains 5 generators of fast and slow linearly increasing voltages, the start inputs of which are combined and connected to the output of the pulse generator, a comparator, the first and second inputs of which are connected 0, respectively, with the outputs of the fast and slow linearly rising voltage generators, the one-shot whose start input is connected to the comparator output, the one-shot output is the output of the device to the analog memory block, the input and output of the delay block are connected respectively to the single-vibrator output and the second input element I. frequency divider by two, input and output which is connected respectively to the output of the pulse generator and the first input of the element AND, the driver of the reference voltage drop, the input of which is connected to the first input of the element AND, the output of the driver of the reference voltage drop is the output of the reference voltage difference of the device, amplifier, the input of which is the analog input of the device, the oscilloscope, the vertical deflection input, the horizontal deflection input and the beam illumination input of which are connected respectively to the output of the amplifier, the output of the slow linearly increasing voltage generator and the output of the element I. FIG. / Have FIG. g W / O /  Rig. 3 ka Storage losG rig..4 R O7b.1 1: II or fa.tf L Editor M. Tsitkina  ) 5 Compiled by B. Venkov Techred M. Morgankorrektor M. Sharoshi - To fr. S ..four / 71 | K 5 I Eh irTj   42