Voltage Controlled Resistor Ic

Although there s no spice component that directly models this device you can easily put one together.

Voltage controlled resistor ic. From the fact that the control signal is well isolated from the resistor terminals. One of the simplest uses of a voltage controlled resistor is an electronically controlled attenuator or volume control. Vcrs are most often built with field effect transistors fets. The circuit is shown in figure 7 and allows the gate control voltage to be the same value as that voltage used without a feedback circuit while preserving.

The answer is yes e g vcr11 but it turns out that virtually any other fet e g jfet and mosfet can be used as a voltage controlled resistor. Vcr4n jfet voltage controlled resistor. The input port voltage controls the value of the resistor between the output ports. This type of circuit is commonly used in electronics to drive current controlled devices like bjt scr etc.

Circuit vc resistor1 cir download the spice file. In a voltage controlled current source circuit as the name implies a small amount of voltage across the input will proportionally control the current flow across the output loads. D gain ranging capability wide range signal attenuation d no circuit interaction d simplified drive. 1 where vin is the differential input voltage kt q is approximately 26 mv at 25 c and i5 and i4 are the collector.

The basic circuit. A common request from spice users is a voltage controlled resistor. 7 3 1 circuit description the differential transistor pair q4 and q5 form a transconductance stage in that the ratio of their collector currents is defined by the differential input voltage according to the transfer function. Gate control voltage v gg be twice as large as v gs in fig ure 5 for the same r ds value.

Avoltage controlled attenuator as one example the circuit in fig. D continuous voltage controlled resistance d high off isolation d high input impedance. Two types of fets are often used. Basic voltage controlled resistor vcr circuits.

There s several ways to do it. A voltage controlled resistor vcr is a three terminal active device with one input port and two output ports. The jfet and the mosfet there are both floating voltage controlled resistors and grounded floating.