Transient EM/Circuit Co-Simulation
A SPICE-based circuit solver and full-wave FDTD solver are computed simultaneously.
XF's transient EM/circuit co-simulation capability combines a time-domain circuit solver with its full wave electromagnetic solver and uses co-simulation to update complex circuit structures at each timestep in an FDTD simulation. This improves the analysis of transient-voltage-suppression (TVS) diodes, chip components and matching networks.
TVS Diodes
TVS diodes are often used in the RF frontend or along data lines to protect sensitive circuitry from an ESD event. Manufacturers provide an equivalent SPICE model consisting of diodes, resistors, capacitors, and inductors to model the VI characteristics of the physical diode. XF’s nonlinear circuit solver is able to handle unidirectional diodes, bidirectional diodes, and other ESD mitigation devices which are represented as an equivalent SPICE circuit.
Chip Components
Two-port, surface mounted passive chip components are commonly used in PCB design. Rather than using ideal components in an FDTD simulation, realistic chip performance can be simulated based on measured data. Manufacturers -- such as Murata, Coilcraft, and Taiyo Yuden -- provide SPICE models for their chips, which can be imported into XF and used as circuit component definitions. During timestepping, XF’s circuit solver updates the cell edge containing the component based on the SPICE model.
Read additional documentation on XF's Netlist Component Definition...
Matching Networks
Two-, three-, and four-port matching networks can be defined as a SPICE model and included in a voltage source within XF. This saves users from defining each element in the matching network as an individual circuit component.
Read additional documentation on XF’s Voltage and Current Sources...
For More Information:
Download our whitepaper to learn more: "Transient EM/Circuit Co-Simulation in XFdtd: A Closer Look at TVS Diodes for ESD Protection"
Watch the Introduction to XFdtd's Transient EM/Circuit Co-Simulation Capability video tour…