VCR2N

N-channel Junction Field-Effect Transistor (JFET) specifically designed to act as a continuous, highly linear voltage-controlled resistor (VCR). Unlike standard switching or amplifying JFETs, the VCR2N is optimized for predictable resistance changes across its drain-source channel (\(r_{DS}\)) in response to a DC bias voltage (\(V_{GS}\)) applied to its gate - Key Technical SpecificationsThe electrical characteristics are highly distinct to ensure smooth control over low-level AC signals:Drain-Source Resistance Range (\(r_{DS}\)): Typically scales from 20 Ω to 60 Ω when fully turned on (\(V_{GS} = 0\,\text{V}\)). Its maximum off-isolation resistance can soar well over 100 kΩ.Gate-Source Cutoff Voltage (\(V_{GS(off)}\)): Varies between -3.5 V and -7.0 V.Gate-Source Breakdown Voltage (\(V_{(BR)GSS}\)): -25 V maximum.Power Dissipation: Rated up to 300 mW.Package Style: Encapsulated in a hermetically sealed, 3-pin metal can package (TO-206AA / TO-18).Applications and Operating PrincipleThe device is intended for small-signal operations where the alternating current (AC) signal lacks a DC component. When operated near the origin of its output characteristic curve (the triode region), the VCR2N exhibits almost pure ohmic resistance. Common use cases include:Variable Gain Amplifiers (VGAs)Automatic Gain Control (AGC) circuitsVoltage-Controlled Oscillators (VCOs)Small-signal attenuators and dynamic filtersTo counteract nonlinearities and minimize harmonic signal distortion, designers frequently implement a simple feedback circuit. This setup couples a fraction of the drain signal back to the gate terminal via a basic resistor divider.