bFunc - Project Journal - May 22 2020
Here’s this week’s development update for bFunc, the open source function generator project.
Buy a board on Gumroad, read the design doc, or browse the source on GitHub.
This Week’s Progress: Researching a bunch of components for the next rev - output opamps, filter topologies, some boost regulators, etc…
May 19, 2020
- There’s such a thing as integrated, dual power supply modules. Whoa.
- CUI Inc makes this honking great dual power module: +12/-12V output at 42mA each
- Datasheet is here
- Footprint is here
May 18, 2020
May 13, 2020
- I had found [Craig]’s post on Hackaday reviewing the MHS5200-A function generator but I didn’t realize he’d gone to the next level and fixed some parts of the design to make it work better. Super cool!
- Swapping out the output driver opamp for a higher slew rate model is instructive!
- The notes on the elliptic filter redesign are also really neat!
May 12, 2020
- Wrote some target specs for next revision - bFunc - Rev2.0 - Specs
- Made a set of quick sims for the output stages of the next rev
- Elliptic Filter - Step Response to 10ns rising edge
- Elliptic Filter - Bode Plot
- Output Driver - AD8065
- Started hardware_rev2!!
- Starting with DDS sheet
- Changed over to AD9834
- Started to add in features
- To-Do: Double check all the decoupling capacitors
- To-Do: Update Crystal (need 75MHz)