525 CSRO with 8-bit DAC
525 : CSRO with 8-bit DAC
- Author: Luca Maddison
- Description: Voltage controlled ring oscillator with 8-bit DAC and analog input
- GitHub repository
- Open in 3D viewer
- Clock: 0 Hz
How it works
Ring oscillator frequency can be changed by either varying Vctrl or leaving it open and using the DAC (Vmax - 1.8V). DAC_enable pin must be held high
How to test
Vary voltage of Vctrl pin and measure frequency of output. Change bits of DAC and measure frequency output. OSC_OUT_DIV is OSC_OUT divided by 64 and can (hopefully) be read by Arduino
External hardware
Power supply (for vctrl) and oscilliscope
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | DAC_bit0 | OSC_OUT_DIV | DAC_enable |
| 1 | DAC_bit1 | ||
| 2 | DAC_bit2 | ||
| 3 | DAC_bit3 | ||
| 4 | DAC_bit4 | ||
| 5 | DAC_bit5 | ||
| 6 | DAC_bit6 | ||
| 7 | DAC_bit7 |
Analog pins
ua | PCB Pin | Internal index | Description |
|---|---|---|---|
| 0 | B4 | 10 | VCTRL |
| 1 | B5 | 11 | OSC_OUT |