The 20-Pin DisplayPort: Full Pinout and Why HDMI Has 19

The search “20 pin displayport male to hdmi” usually arrives at the pinout question wearing a product question’s clothes: someone has counted (or was told) 20 pins on the DisplayPort plug, 19 on the HDMI, and wants to know if a 20-pin DP can become an HDMI by some pin mapping. The honest answer is no – the two standards use their contacts for different electrical purposes – but the pinout itself is genuinely useful knowledge for anyone specifying adapters, cables or test fixtures. This article is the reference: what each pin group in the 20-contact DP connector does, how the count differs from HDMI’s 19, and what the spec versions change.

The 20 Contacts, Group by Group

The connector is small but the architecture is dense. Four functional groups cover all 20 contacts.

Main Link – 8 Pins, 4 Lanes

Pins 13-20 carry the four differential lane pairs (main link 1-4, plus and minus). This is the video, audio and MST highway: DP 1.2’s HBR2 runs 21.6 Gbps total, DP 1.4’s HBR3 runs 27 Gbps, DP 2.1’s HBR4 runs 80 Gbps. Lane count is negotiable – a single-lane DP link still runs 1080p60 on one pair.

AUX, HPD and Power

The AUX channel pair (pins 5 and 7) carries the sideband control: link training, DPCD reads, MST topology and EDID. HPD (pin 3) is the hot-plug line that tells the source a display has arrived. Pins 1 and 9 are +5 V; pins 2, 4, 6, 8, 10, 11 and 12 are ground. The supply pins are what let passive DP-to-HDMI accessories and many sinks draw power from the source.

Why 20 Pins Do Not Map to HDMI’s 19

The pin-count difference is a symptom; the electrical difference is the reason. The two connectors implement different standards at every layer.

Different Signals, Same Size Class

HDMI’s 19 contacts carry TMDS lanes, eARC, CEC and 5 V – a different protocol family with its own training and handshake. DP’s 20 carry lane pairs plus the AUX sideband. Overlaying the two pinouts produces no useful alignment: what is ground on one side is a data lane on the other.

What Conversion Actually Requires

DP-to-HDMI passive adapters work because many DP sources can natively emit a TMDS-compatible signal on selected main-link pins – a source-side courtesy, not a pin mapping. Anything beyond that (HDMI-to-DP, 4K60, audio edge cases) needs the active chip that decodes one protocol and emits the other.

What the Versions Change (and the CONFIG Header)

The physical 20-contact shell has survived every version unchanged – the versions negotiate rates, not pins.

HBR Rates and DSC

DP 1.2 is HBR2 (21.6 Gbps): 4K60 at 8-bit. DP 1.4 is HBR3 (27 Gbps) plus DSC, opening 4K120/144 and 8K-class modes. DP 2.0/2.1 is HBR4 (80 Gbps), the same connector at a higher clock. The 20-contact count is constant; the bandwidth per contact climbs.

The 2-Pin CONFIG Header

On the back of a male DP plug sits a small 2-pin CONFIG connector – it is not part of the 20. Early DPC-style passive DP-to-DVI adapters wired through it. Market listings that say “18 pin” or “16 pin” are counting the subset their particular cable or adapter uses – the shell is 20 contacts either way.

DisplayPort 20-Contact Pinout, Grouped

Real-World Application Scenarios

A cable factory test lab uses the group map to build fixtures: a main-link continuity and crosstalk test needs all four lane pairs; an AUX and EDID test bench drives pins 5, 7 and 3 directly; a power-pinning check loads pins 1 and 9. An adapter designer uses the CONFIG header note to explain why a “passive DP-to-DVI” unit exists at all. A field engineer uses the +5 V pins to understand which adapters are self-powered from the source and which need the USB lead. The same 20-contact shell is the reference point for every one of them, which is why the pinout article anchors the whole DisplayPort batch.

Recommended Internal Resources

Editorial Note: Internal linking recommendation: (1) HDMI to mini DisplayPort – the direction that needs a chip, explained from the protocol side: https://zh-zong.com/hdmi-to-mini-dp-adapter/ (anchor: HDMI to mDP); (2) Thunderbolt to DisplayPort – native DP under the USB-C shell: https://zh-zong.com/thunderbolt-to-displayport/ (anchor: TB to DP); (3) Product catalog – DisplayPort cables and fixtures: https://zh-zong.com/productlist/ (anchor: product list)

Frequently Asked Questions (FAQ)