In lab_3 we built a prototype of our microphone-servo board. Now let's design the schematic of our own PCB. We'll draw a schematic of the microphone amplifier and servo supply and connector from lab 3, using the PCB design tool KiCad (formerly we used Eagle). It is not a very super powerful tool but installs very quickly, can run on multiple platforms, and has lots of user-developed parts libraries. We'll start today the layout of this board and you have time during next week to complete it and send by email.
This is an individual exercise and each student must complete it on their own laptop.
In this exercise we'll draw a schematic of the microphone amplifier and servo supply / connector from lab_3:
Remember that you actually modified some resistor values in lab_3 to bring the LM324 output more in the middle of it working range (see datasheet extract below).
When you are finished with your board schematic, zip your design and send it to email@example.com?subject=micboard schematic for Electronics for Physicists II
The LMC6484 is a rail to rail input and output opamp. However, the input range of the LM234 is limited:
Now let's do the layout of our PCB. This will conclude our exercises with PCB design; after this we'll move on to logic design with FPGAs.
Please observe the following points:
You may find it helpful to again follow the tutorial.
Below shows the template board layout.
When you are finished with your board schematic and layout, send a zip or tgz archive of your design to firstname.lastname@example.org?subject=micboard design for Electronics for Physicists II
Here you have a screenshot of a possible solution (done using Eagle) that uses 2 layers. Polygons have been used for GND (bottom) and 3.3v (top).