Voltage Controlled Amplifier Ic
They are very high performance current in current out devices with two opposing polarity voltage sensitive control ports.
Voltage controlled amplifier ic. The soundlazer vca offers a wide range exponential control of gain and attenuation with low signal distortion. The vcr is one of the numerous interesting circuit elements that can be produced by using a jfet junction field effect transistor with simple biasing. A voltage controlled amplifier can be realised by first creating a voltage controlled resistor vcr which is used to set the amplifier gain. A current ilsc is inserted into this input which controls the gain of the device linerly.
That corporation unveils the new that 2162 the company s first dual blackmer voltage controlled amplifier vca ic. The amplifier can achieve an 80 db dynamic control range with less than 0 2. The part delivers great performance in a tiny package offering 118db dynamic range 130db gain control range and distortion under 0 1 without any adjustment. The part is a low cost space saving solution for multi channel vca applications.
Vcrs manufactured in this way can be obtained as. At some voltage level the entire signal is let through. The device provides a differential input to single ended output conversion with a high impedance gain control input used to vary the gain over a 40 db to 40 db range linear in db v. That 2180 series integrated circuit voltage controlled amplifiers vcas are very high performance current in current out devices with two opposing polarity voltage sensitive control ports.
Thus by inserting an audio signal 10 mv within pin 2 and 3 and with controlling the current on pin 5 the amount of the signal output pin 6 is controlled. A simple linear voltage controlled amplifier can be constructed with one op amp and two jfets see the figure. This modern designed vca is based on the that 2181 series integrated circuit voltage controlled amplifiers vcas. They offer wide range exponen tial control of gain and attenuation with low signal distortion.
This voltage controlled amplifier circuit is simply an op amp having an additional input at pin 5. The vca810 is a dc coupled wideband continuously variable voltage controlled gain amplifier. Figure 8 shows how two amplifiers of the figure 7 type can be used together to make a voltage controlled stereo amplifi er. The parts are trimmed at wafer stage for low thd and control.
Note in this case that the i bias gain control pins of the two otas are shorted together and fed from a single gain control voltage and current limiting resistor. The ic ideal for use in stereo amplifier applications. Things that can force changes to this circuit are many but are mostly limited to larger and smaller input signals and higher or lower supply voltage ranges.