1. Design for Simple Spiking Neuron Model
Mixed-Signal Circuit
Design for Simple Spiking Neuron Model
Abdullah H. Ozcan
Vamshi Chatla
ECE 6332 – Fall 2009 University of Virginia

2. Motivation - 10^11 neurons, each neuron 10-10^5 synapses
- Uses less power than your refrigerator light
- Power matters; decreasing energy/spike

3. Outline
- ADC Circuit
- Neuron Circuit
- Conclusion

4. ANALOG TO DIGITAL CONVERTER

6. Comparator Stage

7. Gain Booster Stage Sharper Transitions in the output
Full voltage swing 7

8. XOR Stage

9. Encoder Stage

10. Simulation Results

17. ADC results without gain booster stage

18. ADC results using gain booster stage

19. ADC (4bit) Summary - Technology: 0.6 um - Avg Power: 14.2 mW
- Max Power: mW
- Transistors used: 528
- Supply Voltage: 5 V
Analog Range: 1 V
Sampling Rate: 100 MHz

20. Izhikevich’s Simple Spiking Neuron Model

21. VLSI Circuit of Izhikevich’s Model
(Jayawan H. B. Wijekon, Piotr Dudek (2007). Spiking and Bursting Firing Patterns of a Compact VLSI Cortical Neuron Circuit, Int. Joint Conference on Neural Networks)

22. VLSI Circuit (0.35 μm0.6 μm)

23. Comparator Part

24. Matlab Results

25. Circuit Results

26. Neuron Circuit Summary
-Transistors used: 12
mW  mW (% 17 decrease )

27. Future Work - ADC, minimizing power
- DAC circuit to drive synaptic input current
- Synaptic Modification Circuit
* Levy's learning neuron model

28. QUESTIONS
Thank You!