Digital standards

Digital standards

As early as the early 1980s, the International Radio Consultative Committee CCIR (InternaTIonal Radio ConsultaTIve Committee) formulated the color TV image digitization standard, called the CCIR 601 standard, which is now changed to the ITU-R BT.601 standard. The standard specifies the sampling frequency used when converting a color TV image to a digital image, and the conversion relationship between RGB and YCbCr (or YCBCR).

(1) Conversion between color spaces

The conversion relationship between RGB and YCbCr color spaces in the digital domain instead of the analog domain is expressed by the following formula:

Y = 0.299R + 0.587G + 0.114B

Cr = (0.500R-0.4187G-0.0813B) + 128

Cb = (-0.1687R-0.3313G + 0.500B) +128

(2) Sampling frequency

CCIR stipulates the common TV image sampling frequency for NTSC system, PAL system and SECAM system. This sampling frequency is also used for TV image signal sampling in remote image communication networks, such as ISDN, video conferencing, CCITT-H.261 and optical fiber communication.

For PAL system and SECAM system, the sampling frequency fs is

fs = 625 × 25 × N = 15625 × N = 13.5MHz

Among them, N = 864 is the number of samples on each scan line.

For NTSC system, the sampling frequency fs is

fs = 525 × 29.97 × N = 15734 × N = 13.5 MHz

Among them, N = 858 is the number of samples on each scan line.

The relationship between the sampling frequency and the synchronization signal is shown in Figure 07-04-1.

Fig. 07-04-1 Sampling frequency

(3) Effective display resolution

For the luminance signal of PAL system and SECAM system, each scanning line samples 864 samples; for the luminance signal of NTSC system, each scanning line samples 858 samples. For all systems, the number of effective samples per scan line is 720. The sampling structure of each scan line is shown in Figure 07-04-2.

Figure 07-04-2 ITU-R BT.601 brightness sampling structure

(4) ITU-R BT.601 standard summary

In order to facilitate the international exchange of programs, in order to eliminate the difference between the standards of digital equipment, and for compatibility between the 625-line TV system and the 525-line TV system, at the 15th Plenary Session of the International Radio Consultative Committee (CCIR) in February 1982 Adopted Recommendation No. 601, and determined to be based on component coding, that is, to encode based on the luminance component Y, and the two color difference components RY, BY, as an international standard for digital coding in TV studios. The standard provides:

(A) Regardless of whether it is a PAL system or an NTSC system, the sampling frequencies of the Y, RY, and BY components are 13.5MHz, 6.75MHz, and 6.75MHz, respectively.

(B) Linear quantization is used after sampling. The number of quantization bits for each sample is 10 bits for the studio and 8 bits for transmission.

(C) The ratio between the Y, RY, and BY components is 4: 2: 2.
---- At the Interim Conference of the International Radio Consultative Committee (CCIR) held in September 1983, three additional points were added:

(A) It is clearly stipulated that the encoded signal is Y, (RY), BY) signal pre-corrected by γ;

(B) Codewords corresponding to quantization levels 0 and 255 are dedicated to synchronization, and quantization levels from 1 to 254 are used for video signals;

(C) Further clarify the correspondence between analog and digital lines, and specify the interval from the end of the digital effective line to the reference time sample point, which is 16 samples for 525 lines, 60 fields / second, and 625 lines , 50 fields / second is 12 samples. Regardless of 625 lines / 50 fields or 525 lines / 60 fields, the number of brightness samples of the digital effective line is 720, and the number of samples of the color difference signal is 360, which is to facilitate system conversion. If the number of brightness samples is divided by 2, the data of the color difference signal is obtained.

Table 07-04-1 gives the sampling format, coding parameters and sampling frequency recommended by ITU-R BT.601.

ITU-R BT.601 recommends using 4: 2: 2 color TV image sampling format. When using this sampling format, Y uses a sampling frequency of 13.5MHz, and Cr and Cb use a sampling frequency of 6.75MHz. When sampling, the sampling frequency signal should be synchronized with the field synchronization and line synchronization signals.

Table 07-04-1 Color TV digitalization parameters (abstract)

(4) CIF, QCIF and SQCIF

In order to use both 625-line TV images and 525-line TV images, CCITT specifies the so-called common intermediate resolution format (CIF, Common Intermediate Format), 1/4 common intermediate resolution format (QCIF, Quarter-CIF) and SQICF (Sub-Quarter Common Intermediate Format) format, specific specifications are shown in Table 07-04-2.

The CIF format has the following characteristics:

① The spatial resolution of the TV image is the resolution of the home video system (VHS, Video Home System), which is 352 × 288.

â‘¡ Use non-interlaced scan.

③ Using the NTSC frame rate, the maximum frame rate of TV images is 30 000 / 1001≈29.97 frames / second.

â‘£ Use 1/2 PAL horizontal resolution, namely 288 lines.

⑤ Encode the luminance and two color-difference signals (Y, Cb, and Cr </ SUB>) separately, and their value ranges are the same as ITU-RBT.601. That is, black = 16, white = 235, the maximum value of color difference is equal to 240, and the minimum value is equal to 16.

Table 07-04-2 CIF and QCIF image format parameters

0.8mm Female Pin Header

0.8mm ( 0.031") Female Header Connector
Category:Board To Board Connectors
Sub-Category:Pin Header Female
Type:0.8mm

0.8mm ( 0.031") Female Headers Overview
Whenever there is a need for fitting small-sized connectors in compact devices, the 0.8mm pitch female header, or sometimes referred to as header connector, is ideally suited for this application. Not only does this female header space-savvy, but it is also designed for vacuum pick and place that makes it suitable for high volume automated manufacturing.

Antenk offers these low profile, easy-install, SMT or THM miniature female connector plugs at high quality and affordable China-quoted price, for board-to-board connection, snuggly fitting the pins of a male header and acting as a receptacle.

Assembly and service is simple with either vertical (straight), elevated or at a right angle configuration/orientation, which can dissipate current of about 1.0 A or less in a tape and reel packaging. The filleted corners can also remove shadowing allowing optimization of LED output.

Also, the 0.8mm pitch female headers are made to work in Arduino boards, Arduino Pro and Arduino Mega with either single or double-row female headers, facilitating connections for programming and incorporation into other circuits. They have the perfect height for clearing the USB-B connector and great for stacking multiple shields.

Female header always called as [Header connector", Antenk provide widely range of header connector, from 2.54mm (.100″ inch) pitch to 0.8mm (0.031 inch) pitch. The number of pins (contacts) is from 2 to 40 pins per orw. There are three type: Straight (Dip Vertical), Right angle, SMT (surface mount).

If you can not find the items you interest from above items, welcome to contact us, and you will always get fully responsive from us.

Applications of 0.8mm Pitch Female Headers
Its small size is most suitable for PCB connections of small equipment and devices such as:
Arduino Boards
Architectural and sign lighting
Retail and display lighting
Fluorescent LED retrofit lighting
Cabinet or furniture lighting
Commercial / residential cove lighting
WiFi equipment
Gaming consoles,
Measurement instruments
Medical Diagnostic and Monitoring equipment
Communications: Telecoms and Datacoms
Industrial and Automotive Control and Test

Mount Type: Through-hole vs Surface Mount
At one side of this female header is a series of pins which can either be mounted and soldered directly onto the surface of the PCB (SMT) or placed into drilled holes on the PCB (THM).

Through-Hole (Poke-In)
Best used for high-reliability products that require stronger connections between layers.
Aerospace and military products are most likely to require this type of mounting as these products experience extreme accelerations, collisions, or high temperatures.
Useful in test and prototyping applications that sometimes require manual adjustments and replacements.
0.8mm vertical single row female header, 0.8mm vertical dual row female header, 0.8mm Elevated single row female header, 0.8mm Elevated dual row female Header, 0.8mm right-angle single row female header and 0.8mm right-angle dual row female header are some examples of Antenk products with through-hole mount type.

Surface-Mount
The most common electronic hardware requirements are SMT.
Essential in PCB design and manufacturing, having improved the quality and performance of PCBs overall.
Cost of processing and handling is reduced.
SMT components can be mounted on both side of the board.
Ability to fit a high number of small components on a PCB has allowed for much denser, higher performing, and smaller PCBs.
0.8mm Right-angle Dual Row female header, 0.8mm SMT Single row female header, 0.8mm SMT Dual row female header and 0.8mm Elevated Dual Row female Header are Antenk`s SMT female headers.

Soldering Temperature for 0.8mm Pitch Female Headers
Soldering SMT female connectors can be done at a maximum peak temperature of 260°C for maximum 60 seconds.

Orientation/Pin-Type: Vertical (Straight) and Right-Angle
0.8mm pitch female headers may be further classified into pin orientation as well, such as vertical or straight male header or right-angle female header.

Vertical or Straight Female Header Orientation

One side of the series of pins is connected to PCB board in which the pins can be at a right-angle to the PCB surface (usually called "straight" or [vertical") or.

Right-Angle Female Header Orientation
Parallel to the board's surface (referred to as "right-angle" pins).
Each of these pin-types have different applications that fit with their specific configuration.

PCB Connector Stacking
Profile Above PCB
This type of configuration is the most common way of connecting board-to-board by a connector. First, the stacking height is calculated from one board to another and measured from the printed circuit board face to its highest insulator point above the PCB.

Elevated Sockets/Female Headers
Elevated Sockets aka Stacked sockets/receptacles or Mezzanine are simply stacked female headers providing an exact distance requirement between PCBs that optimizes electrical reliability and performance between PCB boards.

Choosing this type of stacking configuration promotes the following benefits:
Connector Isolation - the contacts are shrouded preventing cable connection mishaps and good guidance for the mating header connectors.
For off-the-shelf wireless PCB module, stacking height is optimized with elevated sockets.
Offers superior strength and rigidity.
Polarisation prevents users from inverted insertion.

Single, Dual or Multiple Number of Rows
For a 1.0mm straight or vertical female header, the standard number of rows that Antenk offers ranges from 1 to 2 rows. However, customization can be available if 3 ,4 or n number of rows is needed by the customer. Also, the number of contacts for the single row is about 2-40 pins while for dual row, the number contacts may vary from 2-80 pins.

Pin Material
The pins of the connector attached to the board have been designed with copper alloy. With customer`s demand the pins can be made gold plated.

Custom 1.0mm Pitch Female Headers
Customizable 1.0 mm pitch female headers are also available, making your manufacturing process way faster as the pins are already inserted in the headers, insulator height is made at the right size and the accurate pin length you require is followed.
Parts are made using semi-automated manufacturing processes that ensure both precision and delicacy in handling the headers before packaging on tape and reel.

Tape and Reel Packaging for SMT Components
Antenk's SMT headers are offered with customizable mating pin lengths, in which each series has multiple number of of circuits, summing up to a thousand individual part number combinations per connector series.

The tape and reel carrier strip ensures that the headers are packaged within accurately sized cavities for its height, width and depth, securing the headers from the environment and maintaining consistent position during transportation.

Antenk also offer a range of custom Tape and reel carrier strip packaging cavities.

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ShenZhen Antenk Electronics Co,Ltd , https://www.atkconnectors.com