A depletion type N-channel MOSFET is biased in its linear region for use as a voltage controlled resistor. - Sarthaks eConnect | Largest Online Education Community
A guide to using FETs for voltage controlled circuits, Part 1 - EDN
VCR2N Voltage Controlled Resistor Fet (Siliconix)
A guide to using FETs for voltage controlled circuits, Part 1 - EDN
FET as a VVR-Voltage Variable Resistor
FET Current Source Provides a Continuous Constant Current