VGA is the 15-pin analog video connector standard since 1987. It carries RGB analog video signals with horizontal and vertical sync, plus DDC I2C for monitor EDID. Found on PCs, projectors, and legacy monitors.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | RED | Red video, 0.7V p-p, 75 ohm | ADC |
| 2 | GREEN | Green video, 0.7V p-p, 75 ohm | ADC |
| 3 | BLUE | Blue video, 0.7V p-p, 75 ohm | ADC |
| 4 | ID2 / RES | Monitor ID bit 2 (reserved, tie to GND) | I/O |
| 5 | GND | Ground (for horizontal sync) | GND |
| 6 | RED RTN | Red signal return / ground | GND |
| 7 | GREEN RTN | Green signal return / ground | GND |
| 8 | BLUE RTN | Blue signal return / ground | GND |
| 9 | KEY / +5V | Key pin, sometimes +5V for DDC power | PWR |
| 10 | GND | Ground for vertical sync | GND |
| 11 | ID0 / RES | Monitor ID bit 0 (reserved) | I/O |
| 12 | ID1 / SDA | DDC serial data (I2C SDA for EDID) | BUS |
| 13 | HSYNC | Horizontal sync, TTL, 0 or 5V | I/O |
| 14 | VSYNC | Vertical sync, TTL, 0 or 5V | I/O |
| 15 | ID3 / SCL | DDC serial clock (I2C SCL for EDID) | BUS |