This is my first PCB, so please forgive some of my ignorance! I'd like to mount two accelerometers (ADXL193: +/- 250g), orthogonally, on the same PCB, and have a question about noise.
The current design is to have 5 strands of a ribbon cable soldered to the PCB, shown below: 5V, GND, X_OUT_1, NC, X_OUT_2. The "NC" is connected to GND on the DAQ board, but has no connection on the accel PCB, intended to reduce noise between the signal lines. They are single-ended, collected simultaneously.
- C1 and C2 are 0.1uF and 1uF ceramic capacitors, respectively, intended to decouple noise from the power supply.
- ribbon cables to these PCBs from the DAQ board will be up to 16 inches long, and could have ferrite cores along the ribbon cables
- Should this combination of the ground plane/capacitors effectively reduce noise?
- If I want to use a radio on the DAQ, will it take a lot more decoupling?
I appreciate any help! I plan to make this design freely available after having it made and tested.
- swapped the power plane on the top of the board for a ground plane that's tied to the bottom
- added larger keepouts (top + bottom) around the drill holes for #4-40 socket cap screw head
- moved the self-test pins onto the 0.1" grid. unfortunately doing so removed 2 other labels from the board...