34 Oscillating Bones
34 : Oscillating Bones
- Author: Uri Shaked
- Description: A stylish ring oscillator built from SkullFET transistors
- GitHub repository
- Open in 3D viewer
- Clock: 0 Hz
How it works
A simple yet stylish ring oscillator that uses a chain of 21 SkullFET inverters to generate a square wave output. Based on simulation, the oscillator should have a frequency of around 148.6 MHz.
| Pin | Expected frequency |
|---|---|
| osc_out | 148.6 MHz |
| osc_div_2 | 74.3 MHz |
| osc_div_4 | 37.1 MHz |
| osc_div_8 | 18.6 MHz |
How to test
Connect an oscilloscope to one of the output pins (eg. osc_div_8 / uo_out[3]) and enjoy the show.
Simulation results
The following graph shows the output of the oscillator and the divided outputs. It was generated by running make -C docs/layout_sim.png:
The outputs are shifted by 2 volts to make them easier to see in the graph. "uo_out[0]" is the main output of the oscillator and "uo_out[1]"/"uo_out[2]"/"uo_out[3]" are the divided outputs.
Please note that the simulation results do not account for all parasitics, only the primary ones. Consequently, the actual frequency of the oscillator is likely to be lower than the simulated value.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | osc_out | ||
| 1 | osc_div_2 | ||
| 2 | osc_div_4 | ||
| 3 | osc_div_8 | ||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 |