Spice Seminar Simulation Program with Integrated Circuit Emphasis

Spice Seminar Simulation Program with Integrated Circuit Emphasis

Generating a Netlist SPICE Netlist Text file used for simulation Schematic Entry (Common Data format: EDIF) Generate Netlist (SPICE Netlist Different flavors Quite similar) Simulate

Netlist Format C B E model name Q 1 Vo Vin 0 Q 2 N 2222 R 1 Vo Vcc 1 K V 1 Vin 0 V 2 Vcc 0

Number format m u n p f 10 -3 10 -6 10 -9 10 -12 10 -15 K Meg G Alternative Notation 1 e 3 Note 10 M is the same as 10 m! 103 106 109

Which is more readable/maintanable?

Examples of Types of Spice Simulations • Bias Point • DC Sweep • Transient Analysis • AC sweep/Noise • Secondary (nested) sweeps • Parametric • Temperature • Monte Carlo You may find this tutorial helpful at the end of the term

DC sweep Result Vo Output as a function of Vin V 1

Parametric Sweep – creating a variable

Nested Sweep

Bias Point Simulation In a bias point simulation capacitors are modeled as open circuits

Both transient and AC sweeps can be used to determine gains, input and output impedances

Transient and AC Sweep Overview Transient Results Time varying inputs (ex. Sinusoidal, digital clock) Output as a function of time t t AC Sweep Multiple sinusoidal inputs each with a different frequency Results Vo Output as a function of freq

AC Sweep Configuration for Determining Voltage Gain (Av) and Input Impedance (Ri) DC offset is zero “small signal” is 1 Important: when simulating the start frequency cannot be zero!

Resulting Simulation

Plotting Av and Ri

AC Sweep Configuration for Determining Output Impedance (Ro) DC offset is zero “small signal” is applied here (Vo) DC offset is zero “small signal” is zero (Vin = 0)

Transient Sweep Vsin