From VGA to Display Port – the Evolution
That Place is Your Zone to learn the TV, PC Monitor or Digital Projector input Video cable standards, which are very different, and in some cases related to them, mistakes and misunderstands are very confusing.
Video Lesson
How to Understand VGA, DVI, HDMI and DisplayPort Standards and Related Connectors
From VGA to Display Port – the Evolution
From VGA to Display Port – the Evolution
VIDEO 1. HDMI, DisplayPort, VGA, and DVI as Fast As Possible
Video Lesson: Explaining The HDM, DVI, DP and VGA
By TechQuickie
VGA – Video Graphics Array
[D-SUB15 Connector]
PIC. 1 VGA [D-SUB15 Video Connector]
First produced in 1987, VGA has much more enough time to get its roots down.
The maximum usable resolution via VGA is 2048 x 1536 pixels @ 85Hz
The “OLD” VGA standard using [D-SUB 15] today is used as input interface standard in some low-cost Digital projectors.
D-SUB 15 or VGA has commonly used PC to Monitor Standard Cable. Till yesterday, But today in the “BooM” in the evolution of digital revolution as many devices used another interface connectors, related with their Bandwidth and Resolution requirement.
Inventing the new standards for carrying the data to the visualizing device / TV screen, Monitor, Projector , etc. / is commonly related to needs to move a huge amount of data in the base case: trough the pair/s of wire as a physical interface.
In VGA Standard cable we can see some problems:
This is the Signal Degradation in a relation of the cable length, and the wire gauge used into cable make.
- Signal Degradation
- Wire gauge
- Digital Conversion
The Need from another Standard is huge. The problem has resolved by using of a Digital Conversion, with a combination of multiple phases modulation. The Migration to new “DVI” connector begin.
PIC. 2
DVI
PIC. 3
To make things more difficult, there are multiple types of DVI connectors. With the exception of the least famous DVI-A connector, all of them work with uncompressed digital video.
DVI-D is characterized by the single flat blade on one side of the connector, showing no pins above or below the blade. You can see on the PIC.
DVI-I looks very similar to DVI-D but does have four pins surrounding the flat blade. These pins carry an analog signal, for compatibility with the VGA standard. This makes DVI-I connectors able to carry a digital and analog signal.
Both DVI-I and DVI-D connectors have two distinct data rates, also known as single-link and dual-link.
There are several variants DVI-I (Single-Link), DVI-I (Dual-Link), DVI-D (Single-Link) and DVI-D (Dual-Link). Each link type has a maximum allowed data rate that ensures data is not corrupted when transferred from the video card to the monitor.
DVI uses Transition Minimized Differential Signaling (TMDS) for transmitting the data over one twisted wire pair. An SL (single-link) DVI connector consists of four TMDS links. Three of the four links correspond to the red, green, and blue R-G-B Video Signals, while the fourth is a clock control channel. Single-link connectors operate up to 165 MHz and offer 1.65 Gbps of bandwidth. They support resolutions up to 1920×1200 at a refresh rate of 60Hz.
Dual-link connections double the number of RGB TMDS pairs – excluding the clock pair – through parallel connections, thus enabling 2Gbps of bandwidth. They support higher resolutions up to 2560×1600 at a refresh rate of 60Hz. Dual-link connectors are fully backward compatible with single-link operation unless a display mode uses more than 165MHz pixel clock frequency or 24 bits per pixel. In contrast, a single-link connector cannot support dual-link connections at any time; hence,a dual-link connection is preferable in most cases.
DVI connection pins are comprised of the following potential components: parts of an 8×3 rectangle pinout supporting TMDS, DDC, analog vertical sync, power, hot plug detection and ground signals (Pin 1-24); 4 analog pins for RGB and horizontal sync (C1-C4); and a long flat pin for analog ground (C5).
DVI Signals Description
DVI-A connectors have 17 pins (12+5), carry analog signals, and they don’t have a dual-link option. These signals are identical to VGA signals but are presented as an altered configuration.
A VGA – DVI adapter is necessary to connect a VGA video card to a DVI-A monitor or a DVI-A video card to a VGA monitor. DVI-A cables work with both DVI-A and DVI-I connectors.
- DVI-D connectors can only transfer digital video signals. Single-link DVI-D connectors have 19 pins (18+1) and dual-link DVI-D connectors have 25 pins (24+1). DVI-D cables will work with both DVI-D and DVI-I connectors.
- HDMI and DisplayPort connectors can support DVI-D video signals through an adapter, but DVI-D cannot support the additional features that HDMI and DisplayPort possess, such as integrated audio and CEC control. Most digital monitors have a DVI-D connector, while monitors which support both digital and analog signals usually have a DVI-D and VGA connector.
- DVI-I single link connectors have 23 pins (18+5) and dual-link connectors have 29 pins (24+5). DVI-I connectors do not convert analog and digital signals but can accept digital or analog signals – just not both at the same time. If a video card, monitor and cable all have DVI-I connections with the ability to support both analog and digital signals, one mode of operation has to be selected. DVI-I connectors work with all three DVI cable types. However, a male DVI-I cable will not fit in a female DVI-D connector due to its additional analog pins. Hence, when considering the rarity of a DVI-A connector, a DVI-D cable is the most commonly applicable out of the three cable types.
PIC. 4
HDMI [19-PIN] Connector
PIC. 5
If Suggest that DVI is the successor to VGA, the HDMI is a possible successor to DVI. In that Case, We will overview this standard connection in details.
Thanks to the compatibility with the newer high definition televisions, and its compact size compared to DVI, the HDMI connector is increasingly showing up in computers and computer’s displays.
Тhat's why, we will overview this standard connection in details.
HDMI, like DVI, is designed for the digital transmission of uncompressed data.
However, besides a video signal, HDMI can also carry up to eight channels of compressed or uncompressed digital audio.
There are 5 HDMI connector types:
Type A:
- The plug (male) connector outside dimensions are 13.9 mm × 4.45 mm and has 19 pins
Type B:
- This connector is 21.2 mm × 4.45 mm and has 29 pins
Type C:
- This Mini connector is smaller than the type A plug, measuring 10.42 mm × 2.42 mm but has the same 19 pins.
Type D:
- This Micro connector shrinks the connector size to only 6.4 mm × 2.8 mm
Type E:
- The Automotive Connection System with a locking tab to keep the cable from vibrating loose Also has a shell to help prevent from moisture and dirt and from interfering with the signals.
The most famous one, type A, is what you’ll find in most of your appliances today. It’s also the connector we pictured above.
What video connectors do you have on your computer? Let us know in the comments section below the article!
Look inside an HDMI cable:
There are nineteen pins in an HDMI connector, as seen in the following illustration:
PIC. 6
Pins 1 through 9 carry the three TMDS data channels (Transition Minimized Differential Signaling – the technology that allows DVI and HDMI to send high-speed digital data), three pins per channel. TMDS data includes both video and audio information, and each channel has three separate lines for + values, – values, and a ground or data shield.
Pins 10 through 12 carry data for the TMDS clock channel, which helps keep the signals in synchronization. As with the TMDS data channels, there are separate lines for + values, – values, and a data shield.
Pin 13 carries the CEC [ Consumer Electronics Control ] channel, used for sending command and control data between connected devices.
Pin 14 is reserved for future use.
Pins 15 and 16 are dedicated to the DDC [ Display Data Channel ], used for communicating EDID [ Extended Display Identification Channel ] information between devices.
Pin 17 is a data shield for the CEC and DDC channels.
Pin 18 carries a low-voltage (+5V) power supply.
Pin 19 is the Hot Plug Detect, dedicated to monitoring [power up] or [power down] and [plug] or [unplug] events.
There is a variant of cable who creates a connection between DVI and HDMI. It is possible by using the special dual mode video interface chip on the board of PC or media Device.
See on the PIC. the cable is:
PIC. 7
HDMI 1.4 Standard Supports:
- Multi-Channel Audio
- Ethernet Data
- Superior Color Depth
- Wide Video Format
- 30 Hz on 4K Video resolution
HDMI 2.0 Standard Supports:
In addition than older 1.4 standard:
- 4K at 60 Hz
- Wide Aspect ratio up to 21:9
- Multiple stream
PIC. 8
DP (Display Port)
PIC. 9 Standard Display Port
Designer: VESA
Designed: May 2006
Produced 2008 – present
Superseded Digital Visual Interface
Display Port 1.2:
- 4k at 60 Hz
- Multiple Video Streams
- Audio, Ethernet
- Other data signals
- Stereoscopic 3D
- 21:9 Aspect ratios
PIC. 10 Mini Display Port
Display Port 1.3:
- 8K at 60Hz
- Multiple Video Streams
- Audio
- Ethernet
- Other Data Signals
- 4K Stereoscopic 3D
- 21:9 Aspect Ratios
- Adaptive Synchronization
Technical Specifications:
Hot-pluggable:
- Yes
External:
- Yes
Audio signal:
- Optional; 1–8 channels, 16 or 24-bit linear PCM; 32 to 192 kHz sampling rate; maximum bitrate 36,864 kbit/s (4,608 kB/s)
Video signal:
- Optional, maximum resolution limited by available bandwidth
Cable:
- 3 meters for full bandwidth transmission over a passive cable.
- 33 meters over active cable.[1]
Pins:
- 20 pins for external connectors on desktops, notebooks, graphics cards, monitors, etc. and 30/20 pins for internal connections between graphics engines and built-in flat panels.
Electrical Specifications:
Signal Level [V] +3.3
Max. voltage[V] 16.0
Max. current[A] 0.5
DATA:
Data signal
- Yes
Bitrate:
- 1.62, 2.7, 5.4, or 8.1 Gbit/s data rate per lane; 1, 2, or 4 lanes; (effective total 5.184, 8.64, 17.28, or 25.92 Gbit/s for 4-lane link); 1 Mbit/s or 720 Mbit/s for the auxiliary channel.
Protocol
- Mini-packet
PIC. 11 Display Port
{ Source: TechQuickie Videos, WiKipedia }
