US 7,127,384 B2 · Fast simulation of circuitry having SOI transistors

Abstract

A fast transient simulator of SOI MOS circuits uses fast and accurate SOI transistor table models. The simulator uses a representation of a circuit with partitions. Each of partitions is simulated separately for a short time step by numerically solving differential equations describing its transient behavior. Behavior of the whole circuit is simulated in an event driven way where each event corresponds to an integration time step for each partition. Instead of body voltage, the simulator implements a transformation and uses body charge as an independent variable in order to obtain high accuracy and high speed of simulation. Construction of SOI transistor table models results in speed and accuracy enhancements. This transformation allows the reduction of the number of table dimensions exploiting the fact that SOI transistor backgate capacitance is approximately constant.

Claims18

Dependent claims

A method for simulating a silicon on insulator (SOI) transistor, comprising:

receiving a value for a drain voltage of the SOI transistor, a gate voltage of the SOI transistor, and a body charge of the SOI transistor;
accessing a first table to obtain an equilibrium value of the body charge of the SOI transistor, an equilibrium value of a body voltage of the SOI transistor, an equilibrium value of a channel current of the SOI transistor using the drain voltage of the SOI transistor and the gate voltage of the SOI transistor;
generating a deviation value of the body charge of the SOI transistor by comparing the body charge of the transistor with the equilibrium value of the body charge of the SOI transistor;
and
accessing a second table to obtain a body voltage of the SOI transistor, a gate charge of the SOI transistor, a drain charge of the SOI transistor, a source charge of the SOI transistor, a body current of the SOI transistor, and a channel current of the SOI transistor using the drain voltage of the SOI transistor, the gate voltage of the SOI transistor, and the deviation value of the body charge of the SOI transistor.

2 more elements

A system for simulating a silicon on insulator (SOI) transistor, comprising:

means for receiving a value for a drain voltage of the SOI transistor, a gate voltage of the SOI transistor, and a body charge of the SOI transistor;
means for accessing a first table to obtain an equilibrium value of the body charge of the SOI transistor, an equilibrium value of a body voltage of the SOI transistor, an equilibrium value of a channel current of the SOI transistor using the drain voltage of the SOI transistor and the gate voltage of the SOI transistor;
means for generating a deviation value of the body charge of the SOI transistor by comparing the body charge of the transistor with the equilibrium value of the body charge of the SOI transistor;
and
means for accessing a second table to obtain a body voltage of the SOI transistor, a gate charge of the SOI transistor, a drain charge of the SOI transistor, a source charge of the SOI transistor, a body current of the SOI transistor, and a channel current of the SOI transistor using the drain voltage of the SOI transistor, the gate voltage of the SOI transistor, and the deviation value of the body charge of the SOI transistor.

2 more elements

Dependencies are inferred from the claim text.

Fast simulation of circuitry having SOI transistors

Life of this patent

Fast simulation of circuitry having SOI transistors

Life of this patent

Abstract

Claims18