Time-Dependent Temperature in PSpice

In the evolving world of electronics where devices are becoming smaller and yet powerful with increased complexity, simulation tool help us to prototype our design to deliver a complete circuit simulation output.

This content aims to shed light on the crucial role of temperature in our circuit designs and how to capture the effect of temperature with time on components.

With the new release of 23.1 version, you can simulate a circuit where the temperature can vary as the simulation time progresses. The temperature can be expressed as functions/expressions of time in temperature-related parameters like T_ABS or T_REL_GLOBAL

For e.g.: You can define a parameter as shown below {27+100000*CDN_CUR_TIME} and use it to define T_ABS in component model.

The model Rbreak is defined here as

.model Rbreak RES R=1 TC1=0.05 TC2=400u T_ABS={restemp}

The PSpice sample simulation result appears as shown below:

Here, you can observe that the resistance value (lower plot) is increasing due to temperature variation, resulting in a drop in the collector current of BJT (upper plot). You can try different expressions to model temperature variation for the resistor and the BJT. These expressions can be passed on to model temperature parameters, and PSpice can simulate the effects of temperature variation.

Hope you find it interesting and helpful.

Team DesignTech

Cadence Design Systems