SU1691896A1 - Sample-hold unit - Google Patents

Abstract

The invention relates to electronics and can be used in monitoring devices (peak detectors, sampling-storage devices). The purpose of the invention is to increase the storage time of the charge element. The goal is achieved by introducing amplifier 1 and voltage divider i at the output of the device, which restores the original information to the initial value of the input voltage. The device also contains a key element 2, a cumulative element 3 on a capacitor and noBTopntenb 4. 1 Il.

Description

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ABOUT

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ABOUT

The invention relates to electronics and can be used in monitoring devices (peak detectors, sampling-storage devices).

The purpose of the invention is to increase the storage time of the charge element.

The drawing shows a diagram of the device.

The device contains an operational amplifier 1, a key element 2, a storage element 3 on a capacitor, a voltage repeater 4, a voltage divider 5 on two resistors.

The device works as follows.

When the analog signal arrives at the information input of the device, element 2 opens and the input voltage amplified by an amplifier n times, charges element 3 connected to the input of repeater 4, the output of which is connected to divider 5, which reduces the signal n times to its original value.

The discharge of element 3 occurs along the circuit element 3, 2 and along the circuit element 3 - the input of the repeater 4, depends on the resistance of the closed element 2 and the input resistance of the repeater 4.

The device uses low leakage elements (element 2 at field-effect transistors and element 4 with field-effect transistors at the input), which remain almost constant in the considered range of voltage across element 2 (0-6 V). With the above limitations, the storage time of the analog signal is proportional to the voltage on the element 3.

The storage time is defined as the time interval during which the charge on element 2 decreases due to leakage to a value due to the permissible relative error in the fixing of the input voltage,

 -Uo,

where Qo and C are the initial charge and the capacity of element 3.

Through txp, the charge will decrease to

 U0- AQ; AQ ly txp; -Ut,

where Do is the voltage on element 3 at the initial moment of time;

txp is the charge storage time;

Ut is the voltage across element 3 at the time of storage;

1U - leakage current;

1U Uo-Qt;

t - С Up - С Ut С, .. .. v txpГу (Uo-Ut)

Permissible relative error of voltage fixation

au Uo.Ut; txp fau-Uo.

Uoly.

where C const; ly "const,

those. the storage time is directly proportional to the value of U0 - the voltage on the element 3, which explains the presence at the input of the amplifier circuit with a gain factor

and output divider with coefficient

one

Ku - to restore the original value of the analog signal. As the storage time increases, the voltage on element 3 also increases the accuracy of the device, which

allows to increase the display time of the parameters of the monitored value.

Claims (1)

Claims A sample storage device containing a voltage follower, a key element, a storage element on a capacitor, a voltage divider on two resistors, the first output of which is connected to the output of the repeater combined with its inverting input, the non-inverting input of which is connected to the integrated information output of the key element and the first output of the capacitor of the storage element, the control input of the key element is the input of the device mode setting, the second conclusions of the condensation the torus of the storage element and the voltage divider are connected to the zero potential bus device, characterized in that, in order to increase the storage time of the charge, an operational amplifier is inserted into it, the input of which is the information input of the device, and its output is connected to the information input of the key element, the third output of the voltage divider is an information output of the device.