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RINGO9 Characterization

A project log for LED Coupled Logic (LCL)

Reaching sub 1 ns propogation delay with LEDs and bipolar transistors.

timTim 12/12/2020 at 13:560 Comments

I used 9 inverters from two RINGO5 boards to build a single ring oscillator with 9 stages. Due to the lower oscillating frequency, the individual inverters are able to reach a more steady state during switching.

The output at VDD=4.5 V is shown above. The waveform does now rather resemble a digital switching signal.

The output for VDD=5 V is above.

Vdd [V] Idd [mA] Vavg [V] Vmin [V] Vmax [V] Swing [V] Freq [MHz] tpd [ns]
4.5 80 3.36 2.86 3.83 0.97 70.7 0.78
5 92 3.81 3.01 4.54 1.53 58.6 0.94

The tpd and logic levels are very similar for the RINGO5 and RINGO9 confirming sub 1ns tpd for the LCL inverter.

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