VGA DE-15 (HD-15) pinout
VGA Pinout (DE-15 / HD-15)
The 15-pin VGA connector carries analog video as separate red, green, and blue signals (pins 1, 2, 3 with individual returns on 6, 7, 8), horizontal and vertical sync on pins 13 and 14, and the DDC identification channel on pins 12 and 15 with +5 V on pin 9.
| Pin | Signal | Notes |
|---|---|---|
| 1 / 6 | Red / red return | 75 ohm analog red video and its ground. |
| 2 / 7 | Green / green return | Analog green video and its ground. |
| 3 / 8 | Blue / blue return | Analog blue video and its ground. |
| 13 | Horizontal sync | TTL-level H sync. |
| 14 | Vertical sync | TTL-level V sync. |
| 12 / 15 | DDC data / clock (SDA/SCL) | The I²C channel that reads the display’s EDID. |
| 9 | +5 V (DDC power) | Powers the EDID chip; missing on some old cables. |
| 5 / 10 | Grounds | Sync and DDC ground returns. |
| 4 / 11 | Not connected (legacy ID) | Pre-DDC monitor ID lines; unused on modern equipment. |
What it’s used for
VGA is legacy, and legacy means it still shows up: house projectors in older venues, podium plates nobody rewired, and the one presenter laptop dock that only speaks analog. Knowing the pinout mostly means knowing what fails, since nobody terminates VGA in the field anymore.
The video is analog RGBHV, so quality degrades gracefully with cable length and quality rather than cliffing like digital: ghosting means impedance problems, color loss means a dead pin (a missing green pin is the classic magenta image), and wrong resolutions mean the DDC pins are not making it through an adapter chain.
Wiring & termination notes
- Each color rides its own 75 ohm coax inside the cable; cheap uncoaxed VGA cable ghosts at length. 15 meters on good cable is comfortable, more with line drivers.
- A magenta or yellow image is a missing color pin (green or blue respectively), usually a bent pin 2 or 3 in a reused cable.
- EDID problems (wrong or refused resolutions) travel on pins 12/15; docks and adapters that drop DDC force the source to guess.
- The thumbscrews exist because the connector predates strain relief wisdom; use them.
Frequently asked questions
Does VGA carry audio?
No. VGA is video and sync only, which is why every VGA-era podium also has a 3.5 mm audio cable taped to it.
What is the maximum resolution of VGA?
Analog VGA has no hard format ceiling; quality is bandwidth-limited by cable and hardware. In practice 1920 × 1080 or 1920 × 1200 at 60 Hz is a reasonable expectation on decent cable, degrading with length.