eSATA Pinout
External Serial ATA - the 7-pin SATA data signal set in a rugged shielded shell.
Overview
eSATA carries the same seven-conductor SATA data signal set (two differential pairs plus three grounds) in a more robust connector for external cabling. Internal and external cables cannot be mismatched.
Electrically the protocol is identical to internal SATA; eSATA only tightens voltage levels and adds shielding for longer cables. It carries no power - devices need a separate supply.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | A+ (TX+) | UART / PAIR | Transmit differential pair, positive |
| 3 | A- (TX-) | UART / PAIR | Transmit differential pair, negative |
| 4 | GND | GND | Ground |
| 5 | B- (RX-) | UART / PAIR | Receive differential pair, negative |
| 6 | B+ (RX+) | UART / PAIR | Receive differential pair, positive |
| 7 | GND | GND | Ground |
Notes
- Signal pinout is identical to internal SATA data; only the shell and voltage margins differ.
- Plain eSATA carries no power; eSATAp is a separate combined connector.
Reference: SATA-IO eSATA specification; eSATA pinout· verified 2026-06-27