19 pin HDMI type A connector
24 pin DVI-D female connector
HDMI Type A (19-pin, introduced December 2002 by the HDMI Founders consortium) shares identical TMDS electrical signalling with single-link DVI-D: the same differential pair topology, 50 Ω termination, and 200–600 mV differential swing defined in the DVI 1.0 specification published by the Digital Display Working Group in April 1999. Because the two interfaces are electrically equivalent for video, a passive adapter or cable can connect an HDMI source to a DVI-D display with no active components. HDMI adds embedded multi-channel audio, Consumer Electronics Control (CEC, pin 13), and Hot Plug Detect (pin 19), none of which have DVI equivalents; these signals are simply left unconnected in a passive adapter. The maximum TMDS pixel clock shared by DVI and HDMI 1.0–1.4 is 165 MHz, sufficient for 1080p/60 and 1920×1200.
Type A HDMI to DVI-D interface cable
| HDMI Pin | Signal | Wire | DVI-D Pin |
|---|---|---|---|
| 1 | TMDS Data2+ | A | 2 |
| 2 | TMDS Data2 Shield | B | 3 |
| 3 | TMDS Data2- | A | 1 |
| 4 | TMDS Data1+ | A | 10 |
| 5 | TMDS Data1 Shield | B | 11 |
| 6 | TMDS Data1- | A | 9 |
| 7 | TMDS Data0+ | A | 18 |
| 8 | TMDS Data0 Shield | B | 19 |
| 9 | TMDS Data0- | A | 17 |
| 10 | TMDS Clock+ | A | 23 |
| 11 | TMDS Clock Shield | B | 22 |
| 12 | TMDS Clock- | A | 24 |
| 13 | CEC | N.C. | N.C. |
| 14 | Reserved | N.C. | N.C. |
| 15 | SCL | C | 6 |
| 16 | DDC | C | 7 |
| 17 | DDC/CEC Ground | D | 15 |
| 18 | +5V | 5V | 14 |
| 19 | Hot Plug Detect | C | 16 |
- Other pins are not connected
Type B HDMI to DVI-D interface cable
| HDMI Pin | Signal | Wire | DVI-D Pin |
| 1 | TMDS Data2+ | A | 2 |
| 2 | TMDS Data2 Shield | B | 3 |
| 3 | TMDS Data2- | A | 1 |
| 4 | TMDS Data1+ | A | 10 |
| 5 | TMDS Data1 Shield | B | 11 |
| 6 | TMDS Data1- | A | 9 |
| 7 | TMDS Data0+ | A | 18 |
| 8 | TMDS Data0 Shield | B | 19 |
| 9 | TMDS Data0- | A | 17 |
| 10 | TMDS Clock+ | A | 23 |
| 11 | TMDS Clock Shield | B | 22 |
| 12 | TMDS Clock- | A | 24 |
| 13 | TMDS Data5+ | A | 21 |
| 14 | TMDS Data5 Shield | B | 19 |
| 15 | TMDS Data5- | A | 20 |
| 16 | TMDS Data4+ | A | 5 |
| 17 | TMDS Data4 Shield | B | 3 |
| 18 | TMDS Data4- | A | 4 |
| 19 | TMDS Data3+ | A | 13 |
| 20 | TMDS Data3 Shield | B | 11 |
| 21 | TMDS Data3- | A | 12 |
| 25 | SCL | C | 6 |
| 26 | DDC | C | 7 |
| 27 | DDC/CEC Ground | D | 15 |
| 28 | +5V | 5V | 14 |
| 29 | Hot Plug Detect | C | 16 |
- Other pins are not connected
Notes
- The HDMI-to-DVI-D adapter is entirely passive — no signal conversion is required because both interfaces use identical TMDS differential signalling.
- Only the video (TMDS) data pairs, clock pair, DDC/I²C lines, and +5 V power are connected; CEC (HDMI pin 13), the reserved pin (14), and Hot Plug Detect (pin 19) have no DVI counterparts and remain unconnected at the DVI end.
- DDC (Display Data Channel, I²C) is preserved, allowing the source to read EDID data from the DVI display.
- Single-link DVI-D supports a maximum TMDS pixel clock of 165 MHz, setting an upper limit of 1920×1200 or 1080p/60 for passive adapters.
- Type B HDMI (29-pin) maps to dual-link DVI-D, doubling the data bandwidth by adding three additional TMDS data pairs; Type B hardware was defined but never commercially deployed.
- Audio, CEC, and any HDMI Ethernet Channel (HEC, available from HDMI 1.4) are not transmitted over DVI; audio must be carried separately (e.g. via S/PDIF or analogue output).
- DVI-D connectors are keyed differently from DVI-I; a DVI-D plug will seat into a DVI-I socket, but a DVI-I plug cannot be forced into a DVI-D socket.