Industry standard compatibility

Symica provides industry compatibility through the use of industry-standard netlist formats (HSPICE® and Spectre®) and through a set of models and numerical methods that produce results closely matching those of HSPICE® and Spectre® simulators.  In developing the Symica simulation engine we considered many specific features of model files provided by different IC foundries, and developed a collection of model equations that Symica draws upon to implement its models.  At simulation time the Symica engine chooses appropriate model equations to generate results complying with either HSPICE® and Spectre® simulators, as called for in the text-format description for a given model.

Symica uses mathematical models and numerical methods similar to those implemented in modern commercial and "golden" SPICE simulators. Nevertheless all SPICE simulators generate slightly different results. We have tuned Symica's numerical methods to provide accurate simulation results closely matched with those expected from HSPICE® and Spectre® simulators.  We have also taken care to choose default settings for the simulation engine that reduce the number of simulator options that need to be chosen for most common situations, to allow engineers to work more efficiently.

On this page we present simulation results for a few circuits that are sensitive to simulation accuracy and the specifics of the model descriptions.

First circuit: 64-nm CMOS PLL (a circuit that is sensitive to the accuracy of simulation)

Circuit inventory:

  • nodes 4787
  • bsim3v3 890
  • bsim4 6914

Simulation results for the 64-nm CMOS PLL circuit:

Industry standard SPICE simulation result for default set of accuracy SymSpice simulation result for default set of accuracy
Industry standard SPICE simulation result with default accuracy setting SymSpice simulation result with default accuracy setting
Industry standard SPICE simulation result for liberal set of accuracy
Industry standard SPICE simulation result with liberal accuracy setting

Second circuit: CMOS DC/DC converter (a circuit that is very sensitive to the accuracy of simulation)

Circuit inventory:

  • nodes 117
  • bsim3v3 180

Simulation results for the CMOS circuit DC/DC converter:

Industry standard SPICE simulation result for conservative set of accuracy SymSpice simulation result for conservative set of accuracy
Industry standard SPICE simulation result with conservative accuracy setting SymSpice simulation result with conservative accuracy setting
Industry standard SPICE simulation result for default set of accuracy
Industry standard SPICE simulation result with default accuracy setting
Industry standard SPICE simulation result for liberal set of accuracy
Industry standard SPICE simulation result with liberal accuracy setting

Third circuit: bipolar ADC (a circuit that is sensitive to the VBIC model description)

Circuit inventory:

  • nodes 785
  • equations 20609
  • vbic 844
  • capacitor 1237
  • resistor 503

Simulation results for the bipolar ADC circuit:

Industry standard SPICE simulation result for default set of accuracy SymSpice simulation result for default set of accuracy
Industry standard SPICE simulation result with default accuracy setting SymSpice simulation result with default accuracy setting

Fourth circuit: 250 nm CMOS comparator (a circuit that is sensitive to the choice of integration step and algorithm)

Circuit inventory:

  • nodes 40
  • bjt 1
  • bsim3v3 51

Simulation results for the 250 nm CMOS comparator:

Industry standard SPICE simulation result for default set of accuracy SymSpice simulation result for default set of accuracy
Industry standard SPICE simulation result with default accuracy setting SymSpice simulation result with default accuracy setting

Fifth circuit: 250 nm 10-bit ADC (a circuit that is sensitive to the accuracy of transient analysis)

Circuit inventory:

  • nodes 2135
  • bjt 19
  • bsim3v3 4837

Simulation results for the 250 nm 10-bit ADC circuit:

Industry standard SPICE simulation result for default set of accuracy SymSpice simulation result for default set of accuracy
Industry standard SPICE simulation result with default accuracy setting SymSpice simulation result with default accuracy setting

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HSPICE ® is the registered trademark of Synopsys, Inc.

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