SPICE (Simulation Program with Integrated Circuit Emphasis) is an open source analogue circuit simulator, used in IC and PCB design.
Using SPICE to simulate circuits is industry-standard to verify that the circuit works at the transistor level. Since manufacturing ICs (like ASICs) can have high costs, it’s important to get this right before you commit too many resources.
SPICE is old, though. The last stable release was in July 1993, so successor tools are used, including LTspice and Multisim.
Directives
SPICE directives are instructions for circuit behaviour.
- The
.icdirective allows us to specify initial conditions.1- The syntax is
.ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]. - An example of this is:
.ic V(N002-N003)=0 V(V1)=0.
- The syntax is