SU995003A1 - Two-threshold device for checking voltage level - Google Patents

Description

(54) TWO-THRESHOLD CONTROL DEVICE

one

The invention relates to measurement instrumentation, is intended for the tolerance control of the voltage level of time periodic signals and can be used in automatic systems for measuring high frequency parameters of radioelectronic devices, in particular integrated circuits.

A two-threshold voltage level monitor is known, in which the monitored value is compared by level with a constant voltage, consisting of two threshold elements set to upper and lower tolerance limits of the monitored voltage, the matching circuit and the 1J actuator.

However, this device has low performance due to the need to detect and integrate the signal at the output of the threshold and comparing devices.

 Closest to the present invention is a two-threshold voltage monitoring device, in which the controlled value is the same as in the known device.

compared to a constant voltage level. The device contains two threshold elements tuned to the upper and lower limits of the tolerance of the monitored voltage, two triggers, a matching logic, an inhibit element, an actuator, a clock pulse rejrepaTop, a differentiating circuit and a resistive divider of the reference voltage (2).

This device has a higher

10 speed than the first device, however, and it does not allow to realize the maximum speed.

This is due to the fact that stable operation of this device is ensured only

15 when the frequency of the clock pulse generator is less than the frequency of the controlled voltage.

The purpose of the invention is to increase speed.

Claims (2)

This goal is achieved by the fact that in a two-and-half threshold voltage level control device containing a divider of the reference voltage, two threshold elements connected by the first inputs c. the corresponding voltage inputs 399 and the second one with the input terminal of the device, two flip-flops, the first inputs of which are connected to the outputs of the corresponding threshold elements, the matching element, the inputs of which are connected to the outputs of the corresponding triggers and the actuator, the third threshold element is entered and an inverter, and the reference voltage divider is provided with a third output, the first input of the third threshold element being connected to the third output of the reference voltage divider, its second the input is connected to the input terminal of the device, the output of the third threshold element is connected to the input of the inverter and the first input of the executive body, the output of the inverter is connected to the second in: trigger signals, and the second input of the executive body is connected to the output of the matching element. FIG. 1 shows a functional two-threshold device; in fig. 2 stress plots for different points of the circuit. The waveform is chosen to be sine for completeness, although the signal may be periodic pulsed. The device contains the first 1, second 2, third 3 threshold elements, resistors 4-7 of the voltage divider, first 8, second 9 and third 10 pins of the voltage divider, inverter 11, trigger 12 and 13, coincidence element 14, actuator (trigger) 15, input terminal 1 The device operates as follows. The signal Ux under investigation through terminal 16 simultaneously enters the threshold elements 1-3, where it is compared with the reference voltages; The oct is the upper limit of the tolerance zone, U0n2 is the lower limit of the tolerance zone, an auxiliary level lying below the U level, for example, near the constant component level of the signal under study. OPS levels. Vf ,,, Uo are formed with the help of resistors 4-7 voltage divider from the reference voltage Upp. If the signal Uy has an instantaneous value lower than the level UQ, then at the output of the third 3 threshold element there is a high voltage level U (Fig. 2), which, having passed through the inverter 11, sets the first 12 and second 13 triggers to one state - the initial state of the triggers 12 and 13. When the instantaneous value of the signal under study U is exceeded by the level Upf, the inhibitory level is removed from the S inputs of the triggers 8 and 9. Triggers 12 and 13 are prepared to receive information on R-to hoam. If the instantaneous value Uy of the signal Uy2 of the output of the second 2 threshold element is exceeded, the low voltage level Up2 (Fig. 2) lowers, which sets the second 13 rigg to O. Similarly to the low potential and f, -J the first 12 rigger is installed. The information from the single shoulder of the first 12 and from the zero shoulder of the second 13 flip-flops is compiled by the coincidence circuit 14. The result of the analysis from the output of the binary code matching circuit 14 is applied to the D input of the third 15 flip-flop (Fig. 2). The output of this trigger is signaled to the output signal of the third 3 threshold element. When the voltage Ups goes low to a high level, the third trigger 15 records the measurement result: the unit-level of the signal used lies within the tolerance zone, zero is outside the zone (plot TK in Fig. 2). After the measurement result has been fixed by the third trigger 15, the first 12 and second 13 triggers can be transferred to the initial state and prepared for a new measurement during the next oscillation period of the signal under study. The installation of the triggers 12 and 13, as mentioned above, is carried out with the appearance of a high voltage level Up3 at the output of the third 3 threshold element, i.e. simultaneously with the fixation of the measurement result by the third trigger 15. Subsequently, the measurement cycle is repeated in each period of oscillation of the tested sigal. The range of frequencies for which the invention may be used is mainly determined by the speed of the elements used to construct it, in particular threshold elements 1-3. The use of newly introduced elements and connections allows measurements to be made during each period of the signal under investigation, i.e. realize the highest possible device performance. The absence of error pulses is due to the phase coupling of the signal under study and the clock frequency, which records the measurement result. The signal phase is coupled due to the formation of clock signals from the signal under study. At the same time, equal frequencies of the signal under study and clock pulses are ensured. By taking measurements during each period of the voltage fluctuations of the signal under investigation, the device can be used in automatic systems for tracking the level of the signal being inspected. This function is not inherent in known devices. The technique-economic advantage of the proposed device compared with known devices is that it allows to increase the speed of the device. / Claims of the invention A two-threshold voltage level control device containing a reference voltage divider, two threshold elements connected by the first inputs to the corresponding terminals of the reference voltage divider, and the second to the input terminal of the device, two triggers, the first inputs of which are connected to the outputs of the corresponding threshold elements, the coincidence element, the inputs of which are connected to the outputs of the corresponding. triggers, and the executive body, from the fact that, in order to increase speed, the third threshold element is not entered into the inverter, and the reference voltage divider is provided with an output terminal, the first input of the third threshold element is connected to the third output of the reference voltage divider , him. second entrance; connected to the internal terminal of the device, the output of the third threshold element is connected to the input of the inverter and the first input of the actuator, the output of the inverter is connected to the second inputs of the flip-flops, and the second input of the executive is connected to the output of the coincidence element. Sources Sh1formatschi taken into account during the examination 1.Information sheet No. 74/0818, UDC 621.317.721.1. 2. USSR author's certificate tP 625167, cl. G 01 R 19/00, 03/04/75. l / ffje Jl ± JL Jl t / n fug.