DVI-A to VGA Pinout Mapping Guide

DVI-A (DVI-Analog) and the analog portion of DVI-I carry native RGB and sync signals that are electrically identical to standard analog VGA (DE-15). Because the signal formats match, a passive adapter or cable can route video directly between the two interfaces without an active digital-to-analog converter. This guide details the exact pin-to-pin mapping required to bridge DVI-A to a standard 15-pin VGA connector.

Core Signal Pinout Mapping

The primary analog signals on a DVI-A connector are clustered around the cross-ground blade (the "C" pins) on the side of the connector, supplemented by a few standard digital-grid pins for vertical sync and DDC communication.

• Red Video: DVI Pin C1 routes to VGA Pin 1
• Green Video: DVI Pin C2 routes to VGA Pin 2
• Blue Video: DVI Pin C3 routes to VGA Pin 3
• Horizontal Sync: DVI Pin C4 routes to VGA Pin 13
• Analog Ground Return (RGB): DVI Pin C5 (flat ground blade) routes to VGA Pins 6, 7, and 8 (Red ground, Green ground, and Blue ground)

Synchronization and Display Data Channel (DDC) Mapping

In addition to the primary color lines, standard VGA communication requires vertical synchronization and I2C/DDC data lines to allow the host device to read the display's EDID information:

• Vertical Sync: DVI Pin 8 routes to VGA Pin 14
• DDC Data (SDA): DVI Pin 7 routes to VGA Pin 12
• DDC Clock (SCL): DVI Pin 6 routes to VGA Pin 15
• +5V Power: DVI Pin 14 routes to VGA Pin 9
• Sync and Logic Ground: DVI Pin 15 routes to VGA Pins 5 and 10

Passive Compatibility Requirements

For this direct mapping to function, the source video card must output an analog signal. Pure digital outputs (DVI-D) lack the physical C1–C5 pins and internal digital-to-analog conversion hardware, making direct passive routing impossible. When connecting a DVI-A or DVI-I source to a VGA monitor using this exact mapping, the monitor treats the incoming signal natively as a standard 0.7V peak-to-peak analog RGB signal.