Specifications - FS2340 FBD Validation DIMM Probe

The FS2340 Validation DIMM Analysis Probe is a bare printed circuit board (PCB) fabrication that is based on the standard FBDIMM Raw Card B design. With the exception of the four 100-pin logic analyzer connectors, it uses that same layout and components. The PCB itself has a gold surface finish that will allow the use of lead-free processing. The assembly requires 19 BGAs with 0.8 mm pitch and a number of additional surface-mount devices. Additionally, four 100-pin edge-mount connectors with a lead pitch of 0.5 mm require soldering across the top edge of the board.

Product Assembly
Assembly of this product requires a controlled surface mount assembly process with the capability to paste and reflow lead-free solder on very small features. The included Assembly files CD contains the following in Gerber and .pdf format:

• Top and bottom assembly drawing
• Top and bottom solderpaste drawings
• Top and bottom silkscreen and mask drawings
• Top and bottom signal layer artworks (for reference)
• Drill, fabrication, XY data, IPC356 and NCDrill files
• Bill of Materials
• Samtec 100 pin connector drawing
• Fabmaster and UniCAM files for the pcb design

Edge Mount Samtec Connectors
It is strongly recommended that these connectors be hand soldered to the pcb after the rest of the devices have been reflowed onto the pcb. The connector lead pitch is 0.5mm, which will require a skilled assembler with the appropriate soldering iron, light and magnification to solder the leads without defects.

Data Strobe Clock input Pull-up resistor locations
The FS2340 Validation FBD probe has the capability for the addition of pull-up/downs on the differential Data Strobe pair DQS1 and DQS1B. This pair is used as a clock input and the use of the pull-up to Vdd on DQS1 at R36 and a pull-down to Ground on DQS1B at R35 is to eliminate any spurious signal transitions on these lines while the Data Strobes are inactive. The logic analyzer clock input would react to spurious transitions as if they were clock cycles and this would degrade the measurement.The pull-up/down resistor pads are sized for 0402 resistors. Their value should be high (20K ohms) and may be best determined experimentally.

Vertical and Horizontal Clearance Considerations
The FS2340 can use two different termination adapters, depending on the vertical clearance in the customer system. The link below shows a drawing that will help you choose which termination adapter is best for you, and how much vertical and horizontal clearance you will have when using the FS2340.