Product Documentation
Spectre Circuit Simulator Components and Device Models Reference
Product Version 23.1, June 2023

Circuit Reduced Order Model (cktrom)

The circuit reduced order model is described by a set of partial differential equations in the form of:

.

x = Ax + Bu (1)

y = Cx + Du (2)

where Eqn.(1) is the state equation, Eqn.(2) is the output equation, A is nxn matrix, B is nxm, C is mxn, and D is an mxm matrix. x is a vector of state variables. Input u is a vector of voltages at all the ports and output y is a vector of electric current at all the ports. The number of inputs is always equal to the number of outputs. The order of the terminals in the input must be consistent with the matrix equations. In the input file, the matrices A, B, C and D are in the form of long vectors with row order.

This device is not supported within altergroup.

Sample Instance Statement

rom3 (net11 0) cktrom a=[ -2.022852e+14  2.583012e+13  9.553125e+13  9.627727e+13  1.533971e+13 9.987851e+13 4.592012e+13 -1.671024e+14  2.296589e+13 -2.719915e+14 7.668472e+12 -1.564519e+14  8.543123e+13  3.395689e+13 -3.863150e+14 -1.101618e+14 -5.415116e+14 -2.303841e+14  9.627728e+13 -1.711915e+14 -1.001818e+14 -8.123120e+14 -2.272715e+14 -9.965181e+14 1.514961e+14  7.668372e+12 -6.415116e+14 -3.272715e+14 -2.852751e+15 -3.564466e+14 9.999851e+13 -1.761619e+14 -1.312841e+14 -8.967181e+14 -4.563456e+14 -4.068747e+15 ]

b=[3.366776e+06  5.932470e+05 -1.508475e+06  4.349182e+06 -3.128869e+06 -2.995677e+06 -2.831481e+06  2.708942e+06 -4.968876e+06 -3.338945e+06 -3.278564e+06  3.925648e+06 ]

c=[-3.111296e+06  1.593292e+06  3.324594e+06  3.083731e+06  5.887179e+06 3.766094e+06 -5.049263e+05 -4.275158e+06  3.035578e+06 -3.666385e+06  3.424639e+06 -3.832285e+06]

d=[1.254627e-01  0.000000e+00 0.000000e+00  1.236790e-01 ]

Instance Syntax

Name  sink0  src0  [sink1]  [src1]  [sink2]  [src2]  [sink3]  [src3] ... cktrom parameter=value ...

Instance Parameters

m

1

Multiplicity factor.

a

[...]

Coefficient matrix A of state equations.

b

[...]

Coefficient Matrix B of state equations.

c

[...]

Coefficient matrix C of output equations.

d

[...]

Coefficient matrix D of output equations.

Operating-Point Parameters

i

[...] A

Port currents.

v

[...] V

Port voltages.

pwr

(W)

Power dissipation.

Related Topics

Current Probe (iprobe)

Circuit Components


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