Vanadium dioxide (VO ₂) devices undergo a thermal insulator-metal-transition by current or voltage injection. In this work, we utilize a dedicated technology Computer-Aided Design (TCAD) modeling approach to simulate thermal-induced resistive switching effects in VO ₂ devices. In particular,we investigate how the heat dissipation modulates the VO ₂ device behavior. We employ a mixed-mode Simulation Program with Integrated Circuit Emphasis (SPICE)—TCAD approach to simulate the relaxation oscillator circuit based on VO ₂ device, and we show the entangled self-oscillatory behavior of temperature and voltage across the device. Our findings provide essential guidelines for the design of VO ₂ oscillators to be exploited to realize oscillatory neural networks circuits for neuromorphic computing.