Reddit:Electronics

I would like to share my DIY digital signal generator. I constructed it using an 8-bit R2R DAC to produce a variety of waveforms including sine, sawtooth, triangle, ramp, square, and noise. Additionally, you can create arbitrary waveforms.

The signal generator's speed varies based on the waveform type and resolution. A full 8-bit sine wave can reach a maximum frequency of approximately 10-20 kHz, while other waveforms are slightly faster. If needed, the resolution can be decreased to achieve higher frequencies.

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I used a simple emitter follower as an output buffer.

R2R DAC Digital Waveform Generator

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Typically, each unit(bit) of an R2R DAC consists of a pair of resistors, with the second resistor having half the value of the first. However, my R2R DAC is constructed using identical resistors, which eliminates the need for special values. Double the value of the first resistor by simply connecting two resistors of the same value in series. By doing so, R1 and R2 function as a 2K resistor. Any value between 1K and 100K will suffice, therefore, use the value that you have the most of. Maintain a consistent value throughout the entire R2R ladder.

One bit of R2R DAC