SU669485A1 - Dynamic differentiating circuit - Google Patents

Description

I

The invention relates to electrical engineering, V in particular to dynamic differential circuits, and can be used in automation devices and radio engineering, for example, in semiconductor integrated circuits as output and transducer circuits in non-recursive and recursive filters on charge-coupled devices.

Known dynamic differentiating irt, containing capacitors and analog switches {1.

Such devices cause distortion of the output pulses due to the cleaving of the tip of the pulse and its tightening.

The closest proposed is a daisy chain with a capacitor in the serial branch, an analog switch and a resistor 2 in the parallel branch.

This differentiating circuit also has the disadvantage of distortion of the output pulse. In addition, such devices are difficult to implement in semiconductor integrated circuits with minimal dimensions.

2

The purpose of the invention is to reduce the distortion of the input pulses.

This is achieved in that in a circuit containing a serially connected capacitor and a key controlled by pulses in phase with the input signal pulses, an additional capacitor connected in parallel and an additional key controlled by the pulses of the input signal are connected between the key output and the total length.

FIG. 1 shows an electrical diagram of a dynamic differentiating circuit; on fkt. Fig. 2 shows the diagrams of the control pulses fi and pg for controlling the analog keys, as well as the diagrams of the input keys. and output pulses of the OUT dynamic differentiating circuit.

Claims (2)

The circuit contains series-connected main capacitor 1 and main analog switch 2, to which are connected in parallel the additional capacitor 3 and the additional analog switch 4 connected to the common bus. The dynamic differentiating chain works as follows. If the input of the circuit impulses UBX. common-mode pulses v. then at the moment of action of the pulses, the switch 2 opens and the series-connected capacitors 1 and 3 are charged before the voltage UBX, and the voltage UBX is applied to the capacitor 3 - those С is the capacitor 1 capacitance, Сд is the capacitor 3 capacitance impulse. It includes U7UCH 4, which discharges the capacitor 3. A rectangular impulse equal to the duration of the pulses is discharged at the capacitor 3. The amplitude of the output pulses depends on the nature of the input pulses UBX When the amplitude of the input pulses is constant output pulses, since the capacitor 1 is charged with pre-voltage Ug and the circuits of capacitors 1, 3 do not flow charging currents during the action of UBX pulses. When modulated input pulses with a modulation frequency fc of the pulse are output, pulses with amplitude equal to the difference between adjacent input pulses of the output () - c7G.Kbivh1pT-- te n - the sequence number of the pulse. The transmission coefficient for the voltage of the dynamic differentiating circuit in the operator form can be written: C (iZ) Cg + C (Z - operator Z transform. The maximum transfer coefficient of the pulse input voltage takes place at a clock-time cm-ft (z -1) and is - - -; SJ The minimum transmission coefficient, equal to zero, the chain has at zero frequency (Z 1). There are no distortions of the output pulses, since there is no transient process of capacitance C. The output pulses do not tighten, since analog switch 4 almost instantly discharges capacitor 3 during the action of pulses in 2 Circuit is realized as a semiconductor MOS integrated circuit based on MDP capacitance dka units picofarad. The area occupied by the dynamic differentiating circuit on a semiconductor chip does not exceed 0.05 mm. DETAILED DESCRIPTION OF THE INVENTION A dynamic differential circuit comprising a capacitor connected in series and a key controlled by pulses in phase with the input signal pulses, such that, in order to reduce distortion of the output pulses, an additional capacitor connected in parallel with the common bus and connected additional key, controlled by pulses, antiphase pulses of the input signal. Sources of information taken into account in the examination 1. Foreign radayelectronics, 1975, 1, p. 56, rice 36. 2.Gostev V.I. Corrective devices with interrupters. Kiev, Technique, 1968, p. 7, fig. 2d