Introduction to Tanner EDA TSpice Introduction to Tanner

Introduction to Tanner EDA T-Spice Introduction to Tanner EDA -Spice T Eitan Shapira

Introduction • SPICE – Simulation Program with Integrated Circuit Emphasis • Spice was originally developed in Berkley university at the 60’s • The Spice language is universal • Provides the engineer with a great analysis ability 2 Introduction to Tanner EDA -Spice T Eitan Shapira

How does it work? Spice is a program that collects from the user the circuit defining parameters via a code and analyze the circuit using its preloaded equations defining each component in the circuit. The code that describes the circuit called Netlist For Example: 3 Introduction to Tanner EDA -Spice T Eitan Shapira

Example Consider the following RC circuit: You must plot the Bode diagram of both HP and LP signals meaning VLP(f)/VIN(f) and VHP(f)/VIN(f) 4 Introduction to Tanner EDA -Spice T Eitan Shapira

Solution: 2 1 GND 1. Mark the different nodes in relevant names 2. Start writing the Spice code 5 Introduction to Tanner EDA -Spice T Eitan Shapira

Spice code for this example: And the result… 6 Introduction to Tanner EDA -Spice T Eitan Shapira

Ok, but what if we don’t remember the Spice syntax? ? ? Is it impossible for us to perform a simulation in Spice? Not at all!!! Tanner T-Spice is equipped with a button just for this case: The insert command button 7 Introduction to Tanner EDA -Spice T Eitan Shapira

The Insert Command Wizard: Options Menu Dynamic screen 8 Introduction to Tanner EDA -Spice T Eitan Shapira

For example let’s assume that we forgot how print our results Add relevant data Choose Output and press AC results 9 Introduction to Tanner EDA -Spice T Eitan Shapira

Example 2: Consider the CMOS inverter: Calculate t. PLH, t. PHL, t. PD, tr, tf 10 Introduction to Tanner EDA -Spice T Eitan Shapira

Solution: in order to find all these we will set up a pulse in the time domain and perform measurements accordingly and then we could ether conclude the parameters from the output plot or use Spice. MEASURE command Spice circuit (Code): 11 Introduction to Tanner EDA -Spice T Eitan Shapira

Now for the measurements and simulation: The results: 12 Introduction to Tanner EDA -Spice T Eitan Shapira

View the result via W-Edit: 13 Introduction to Tanner EDA -Spice T Eitan Shapira

Conclusions: • T-Spice is a very powerful tool • The integrity of the result relies only on the designer – Spice can not know what is it you would like to find, it is after all a machine • Memorizing the entire syntax is not an easy task at all • The absence of the circuit view is very confusing when the circuit is very complicated 14 Introduction to Tanner EDA -Spice T Eitan Shapira

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