Method of identifying a value of an unknown circuit component in an analog circuit

Patent metadata

Field	Value
Publication number	US-9697321-B2
Application number	US-201414311809-A
Country	US
Kind code	B2
Filing date	Jun 23, 2014
Priority date	Jun 23, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A method for identifying a value of an unknown circuit component for an analog signal having a known output profile in which a simulation list of the analog circuit is first created including the component with the unknown value. A transfer function for the known output value is then created using a programmed processor and the transfer function is then solved by the processor for the value of the unknown component. For nonlinear circuit components, a linear model is substituted for the nonlinear components prior to creating the simulation list.

First claim

We claim:

1. A method for creating a simulation file for simulating an analog circuit having an unknown circuit parameter, the method comprising:
receiving, by a processor, as inputs to a circuit simulation program executed by the processor, values of individual components of an analog circuit and respective interconnections of the individual components, for creating the simulation file of the analog circuit, wherein the respective interconnections are represented by nodes within the simulation file, wherein a first value of a first component of the individual components is an unknown circuit parameter of the analog circuit;
determining, by the processor, based at least partially on component types of the individual components, that a second component of the individual components is a nonlinear component;
obtaining, by the processor, from a database of mathematical models for nonlinear components, a direct current (DC) mathematical model corresponding to the component type of the second component;
determining, by the processor, a linear function for the second component for at least a portion of an operating range of the second component to substitute for the second component in the simulation file;
generating, by the processor, a transfer function from the simulation file for one or more nodes of the simulation file;
determining, by the processor, the first value for the first component from the transfer function using a known input/output profile for the analog circuit;
executing, by the processor, the simulation file using the determined first value to simulate operation of the analog circuit for determining a simulated output profile; and
based at least partially on determining that a difference between the simulated output profile and the known input/output profile is less than a threshold error amount, outputting, by the processor, a result indicating that the created simulation file has passed validation.

2. The method as defined in claim 1 wherein the transfer function comprises a Laplace transfer function.

3. The method as defined in claim 1 wherein the simulated output profile is in the time domain.

4. The method as defined in claim 1 wherein the simulated output profile is in the frequency domain.

5. The method as defined in claim 1 further comprising
adjusting an initially determined value for the first value based on the difference being initially greater than the threshold error amount; and
repeating execution of the simulation file using the adjusted first value.

6. The method as defined in claim 5 , further comprising recursively repeating adjustment of the first value and execution of the simulation file until the difference is less than the threshold error amount.

7. A method for creating a simulation file for simulating an analog circuit having an unknown circuit parameter, the method comprising:
receiving, by a processor, as inputs to a circuit simulation program executed by the processor, values of individual components of an analog circuit and respective interconnections of the individual components, for creating the simulation file of the analog circuit, wherein the respective interconnections are represented by nodes within the simulation file, wherein a first value of a first component of the individual components is the unknown circuit parameter of the analog circuit;
generating, by the processor, a transfer function from the simulation file for one or more nodes of the simulation file;
determining, by the processor, the first value for the first component from the transfer function using a known input/output profile for the analog circuit;
executing, by the processor, the simulation file using the determined first value to simulate operation of the analog circuit for determining a simulated output profile;
adjusting, by the processor, an initially determined value for the first value based on the difference being initially greater than the threshold error amount;
repeating, by the processor, execution of the simulation file using the adjusted first value; and
based at least partially on determining that a difference between the simulated output profile and the known input/output profile is less than a threshold error amount, outputting, by the processor, a result indicating that the created simulation file has passed validation.

8. The method as defined in claim 7 where the transfer function comprises a Laplace transfer function.

9. The method as defined in claim 7 wherein the simulated output profile is in the time domain.

10. The method as defined in claim 7 wherein the simulated output profile is in the frequency domain.

11. The method as defined in claim 7 , further comprising substituting, in the simulation file, for a nonlinear component of the analog circuit, a linearized model of the nonlinear component.

12. A method comprising:
receiving, by a processor, as inputs to a circuit simulation program executed by the processor, values of individual components of an analog circuit and respective interconnections of the individual components, for creating a simulation file of the analog circuit, wherein the respective interconnections are represented by nodes within the simulation file, wherein a first value of a first component of the individual components is an unknown circuit parameter of the analog circuit;
generating, by the processor, a transfer function from the simulation file for one or more nodes of the simulation file;
determining, by the processor, the first value for the first component from the transfer function using a known input/output profile for the analog circuit;
executing, by the processor, the simulation file using the determined first value to simulate operation of the analog circuit for determining a simulated output profile; and
based at least partially on determining that a difference between the simulated output profile and the known input/output profile is less than a threshold error amount, outputting, by the processor, a result indicating that the created simulation file has passed validation.

13. The method as defined in claim 12 where the transfer function comprises a Laplace transfer function.

14. The method as defined in claim 12 further comprising
adjusting an initially determined value for the first value based on the difference being initially greater than the threshold error amount; and
recursively repeating adjustment of the first value and execution of the simulation file until the difference is less than the threshold error amount.

15. The method as defined in claim 12 further comprising:
determining based at least partially on component types of the individual components, that a second component of the individual components is a nonlinear component; and
substituting, in the simulation file, for the nonlinear second component, a linearized model of the nonlinear second component.

16. A method comprising:
receiving, by a processor, as inputs to a circuit simulation program executed by the processor, values of individual components of an analog circuit and respective interconnections of the individual components, for creating a simulation file of the analog circuit, wherein the respective interconnections are represented by nodes within the simulation file, wherein a first value of a first component of the individual components is an unknown circuit parameter of the analog circuit;
determining, by the processor, that a number of the components in the simulation file exceeds a threshold number;
partitioning, by the processor, the analog circuit into at least two sub-circuits and analyzing ea

Assignees

• Hitachi Ltd
• Hitachi Ltd

Inventors

• Xiao Yuan
• Mccune Donald J
• Wang Can
• Chen Heming
• Phatak Sujit
• Ito Yasuhiro

Classifications

• G06F30/367

  Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods · CPC title

• Y02T10/82

  Elements for improving aerodynamics · CPC title

• G06F30/398 Primary

  Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36) · CPC title

• G06F17/5081 Primary

  Physics · mapped topic

• G06F17/5036

  Physics · mapped topic