Using Spice in Lab Practicing for Analog ASIC Design

1. 2038 Analog integrated circuits Using Spice in Lab Practicing for Analog ASIC Design Goran Jovanović, Faculty of Electronic Engineering University of Niš Serbia and Montenegro

2. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software (schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

3. Introduction SPICE (Simulation Program with Integrated Circuit Emphasis) was introduced in May 1972by the University of Berkeley, California. It soon became a standard for electronic circuitsimulation, used by both, the industry and the universities. This fact is based on the technicalexpertise of the developers of SPICE: especially Prof. Pederson, and Prof. Nagel.

4. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software (schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

5. Parts of Spice software(schematic, simulator and wave-form viewer) Design entry can be generated by textual or schematic editor. When the simulator finish its job, results is an output binary or an ascii file. For view or print simulation results is used software named as wave-form viewer.

6. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software description(schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

7. Spice software on market and making choice There are many Spice software in the marked: Star-Spice, Smart-Spice, Tanner T-Spice, PSpice, Intuisoft Spice,… The professional analog designer in the most company use Synario HSpice also named like Star-Spice. This software has a superior mathematical solution and the “gold” accurate simulation. A software for Student practice must be free and easy available. In category of free Spice software good choice is PSpice (evaluation student version). PSpice has friendly shell with all three parts of the software (schematic, simulator and a wave-form viewer)

8. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software description(schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

9. Library models and design rules for select technology For present student practice it was used library models, level 6, for CMOS 1.2mm double-metal double-poly technology

10. Library models and design rules for select technology MOS transistors attributes like: L - channel length W - channel width AD,AS - drain & source diffusion area PD,PS - drain & source diffusion perimeters NRx – relative resistance of drain,… … mast be set with respect of design rules for this technology

11. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software description(schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient and AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

12. First example: Inverter (DC) - Schematic editor is used for design entry. - DC analysis setup and DC sweep setup is done.

13. First example: Inverter (DC) DC simulation result: Output voltage in term of voltage V2

14. First example: Inverter (TRANSIENT) - Schematic editor is used for inverter design entry. - Transient analysis setup is done.

15. First example: Inverter (TRANSIENT) Transient simulation result: Input and output voltage

16. First example: Inverter (TRANSIENT) Transient simulation result: Inverter power consumption

17. First example: Inverter (AC) - Schematic editor is used for inverter like voltage amplifier design entry. - AC analysis setup is done.

18. First example: Inverter (AC) AC simulation result: Inverter amplifying [dB] in term of input frequency. Second probe cursor display maximal amplifying 27dB and first cursor display upper cutoff frequency at 595MHz.

19. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software (schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

20. Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line Circuit propagation delay time simulation for inverter with current supply. Parameter is value of V3 voltage source.

21. Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line Parametric transient simulation result: Input and output voltage of delay line for different value of voltage V3 like parameter.

22. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software (schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

23. Third example: Delay Locked Loop • Also, Spice software can be used for simulation of some complex circuits like DLL. • Complete DLL circuits is consisted from: • phase detector, • charge pump, • LP filter and • voltage controlled delay line. Phase detector who is implemented like True Single Phase Logic circuits.

24. Third example: Delay Locked Loop Classic Charge Pump circuit scheme Four stages Voltage Controlled Delay Line circuit scheme.

25. Third example: Delay Locked Loop Hierarchical schema of DLL circuits shows interconnection between components

26. Control Voltage Referent clock Output clock

27. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software description(schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

28. Conclusion After six years experience of using PSpice software in a laboratory practice, I can note: • students (an absolutely beginners) can 15 minutes after introduce time to start with an independent work, • 45 minutes after, students usually finish their first simulation, Friendly environment enables short training time and a clearly presentation of design structure and simulation results.

29. 2038 Analog integrated circuits Content • Introduction • Parts of Spice software description(schematic, simulator and wave-form viewer) • Spice software on market and making choice • Library models and design rules for select technology • First example: DC, Transient, AC simulation of CMOS Inverter • Second example: Parametric simulation of Inverter like Voltage Controlled Delay Line • Third example: Delay Locked Loop • Conclusion • References

30. References • Avant!, Star-Hspice Manual, Release 1998.2, July 1998 • OrCad, PSpice reference guide, 2000. • San Jose State University, EE124 Web Site - Introduction to PSPICE, http://www.engr.sjsu.edu/ee124/p-intro.html