3.4 SAMA5D27/BGA289 Custom Test Board
This is a custom board solely designed for testing MPU+SDRAM configurations not covered by the SAMA5D24/BGA256 test board. It features two individual sets of SAMA5D27 MPUs paired with 1x32-bit LPDDR-SDRAM and 1x32-bit LPDDR2-SDRAM. Each set has its own power management integrated circuit (PMIC).
The layer stack-up is shown in the following table. Since both sets are on the same board, they share the same stack-up.
| Layer Name | Type | Material | Thickness [mm] | Thickness [mil] | Dielectric material | Dielectric constant |
|---|---|---|---|---|---|---|
| Top Overlay | Overlay | – | – | – | – | – |
| Top Solder | Solder Mask/Coverlay | Surface Material | 0.02 | 0.79 | Solder Resist | 3.5 |
| L1-TOP | Signal | Copper | 0.035 | 1.38 | – | – |
| Dielectric 1 | Dielectric | Prepreg | 0.09 | 3.54 | FR-4 | 4.2 |
| L2-GND | Signal | Copper | 0.018 | 0.71 | – | – |
| Dielectric2 | Dielectric | Core | 0.1 | 3.93 | FR-4 | 4.2 |
| L3-INT3 | Signal | Copper | 0.018 | 0.71 | – | – |
| Dielectric3 | Dielectric | Prepreg | 0.95 | 37.4 | FR-4 | 4.2 |
| L4-INT4 | Signal | Copper | 0.018 | 0.71 | – | – |
| Dielectric4 | Dielectric | Core | 0.1 | 3.93 | FR-4 | 4.2 |
| L5-VDD | Signal | Copper | 0.018 | 0.71 | – | – |
| Dielectric5 | Dielectric | Prepreg | 0.09 | 3.54 | FR-4 | 4.2 |
| L6-BOTTOM | Signal | Copper | 0.035 | 1.38 | – | – |
| Bottom Solder | Solder Mask/Coverlay | Surface Material | 0.02 | 0.79 | Solder Resist | 3.5 |
| Bottom Overlay | Overlay | – | – | – | – | – |