Changes

Due to the large number of components being placed in the limited space available on the digital board, Altium's auto-router proved completely useless. Therefore, I routed the board manually. Despite Altium's revolutionary convergence of schematic and PCB design into a single program, this was no easy task. During the routing process, I had to take into account not only the connections that had to be made, but also things such as avoiding crosstalk and minimizing trace length for sensitive components. I was able to complete routing after several weeks of work. The digital board design has since been completed and the board has been printed. It is currently awaiting assembly.

Due to the large number of components being placed in the limited space available on the digital board, Altium's auto-router proved completely useless. Therefore, I routed the board manually. Despite Altium's revolutionary convergence of schematic and PCB design into a single program, this was no easy task. During the routing process, I had to take into account not only the connections that had to be made, but also things such as avoiding crosstalk and minimizing trace length for sensitive components. I was able to complete routing after several weeks of work. The digital board design has since been completed and the board has been printed. It is currently awaiting assembly.

The analog board provided a host of new challenges. The basic schematic for the transimpedance amplifier on the analog board was completed by Igor and Dr. Jones before the semester. Inputting the schematic into Altium was not very difficult. However, one problem I encountered was that the analog board contains 32 copies of this amplifier circuitry. After failing to find any way to insert multiple copies of both the schematic and its corresponding PCB layout, I decided to insert only single copies if each schematic page, and copy and paste the PCB layout to produce 32 copies of the amplifier circuitry. At first this seemed like a quick and easy way to get all of the necessary circuitry onto the PCB. However, I eventually discovered that this procedure would lead to major problems with the board assembly process (due to duplicate component designators, and for other reasons). Fortunately, this revelation came around the same time that Igor and Dr. Jones found a problem with the performance of the amplifier circuit. Making any changes to the amplifier circuit at this point will require a major reroute of all the traces on the analog  board. Since the board needs to be completely redesigned anyway, this will give me another chance to find a way to match schematics with all 32 copies of the amplifier circuitry.

The analog board provided a host of new challenges. The basic schematic for the transimpedance amplifier on the analog board was completed by Igor and Dr. Jones before the semester. Inputting the schematic into Altium was not very difficult. However, one problem I encountered was that the analog board contains 32 copies of this amplifier circuitry. After failing to find any way to insert multiple copies of both the schematic and its corresponding PCB layout, I decided to insert only single copies of each schematic page, and copy and paste the PCB layout to produce 32 copies of the amplifier circuitry. At first this seemed like a quick and easy way to get all of the necessary circuitry onto the PCB. However, I eventually discovered that this procedure would lead to major problems with the board assembly process (due to duplicate component designators, and for other reasons). Fortunately, this revelation came around the same time that Igor and Dr. Jones found a problem with the performance of the amplifier circuit. Making any changes to the amplifier circuit at this point will require a major reroute of all the traces on the analog  board. Since the board needs to be completely redesigned anyway, this will give me another chance to find a way to match schematics with all 32 copies of the amplifier circuitry.

The backplane design is currently in progress. It should be relatively easy to complete. All that remains to be done is to add the LEMO connectors and power inputs. The board is simple enough that it can be routed completely by the auto-router, though a quick hand routing will probably be superior. I anticipate that I can complete the backplane with a few days of concentrated work over break.

The backplane design is currently in progress. It should be relatively easy to complete. All that remains to be done is to add the LEMO connectors and power inputs. The board is simple enough that it can be routed completely by the auto-router, though a quick hand routing will probably be superior. I anticipate that I can complete the backplane with a few days of concentrated work over break.