Slim 2.5-inch SATA devices, 5 mm in height, use the twenty-pin SFF-8784 edge connector to save space. By combining the data signals and power lines into a slim connector that effectively enables direct connection to the device's printed circuit board (PCB) without additional space-consuming connectors, SFF-8784 allows further internal layout compaction for portable devices such as ultrabooks.
| Bottom | Top | ||||||
|---|---|---|---|---|---|---|---|
| Pin | Function | Pin | Function | Pin | Function | Pin | Function |
| 1 | Ground | 6 | Unused | 11 | Ground | 16 | +5 V |
| 2 | Ground | 7 | +5 V | 12 | B+ (transmit) | 17 | Ground |
| 3 | Ground | 8 | Unused | 13 | B− (transmit) | 18 | A− (receive) |
| 4 | Ground | 9 | Unused | 14 | Ground | 19 | A+ (receive) |
| 5 | LED | 10 | Ground | 15 | +5 V | 20 | Ground |

