AD9388ABSTZ-5P datasheet(17/28 Pages) AD

17 / 28 page

AD9388A

Rev. B | Page 17 of 28

THEORY OF OPERATION

ANALOG FRONT END

The AD9388A analog front end comprises three 10-bit ADCs

that digitize the analog video signal before applying it to the CP.

The analog front end uses differential channels to each ADC to

ensure high performance in a mixed-signal application.

The front end also includes a 12-channel input multiplexer that

enables multiple video signals to be applied to the AD9388A.

Current and voltage clamps are positioned in front of each ADC

to ensure that the video signal remains within the range of the

converter. Fine clamping of the video signals is performed

downstream by digital fine clamping in the CP.

For component 525i, 625i, 525p, and 625p sources, 2× over-

sampling is performed, but 4× oversampling is available for

component 525i and 625i. All other video standards are 1×

oversampled. Oversampling the video signals reduces the cost

and complexity of external antialiasing (AA) filters with the

benefit of an increased signal-to-noise ratio (SNR).

HDMI RECEIVER

The HDMI receiver on the AD9388A incorporates active

equalization of the HDMI data signals. This equalization

compensates for the high frequency losses inherent in HDMI

and DVI cables, especially those with long lengths and high

frequencies. It is capable of equalizing for cable lengths up to

30 meters to achieve robust receiver performance at the highest

HDMI data rates.

With the inclusion of HDCP, displays can receive encrypted

video content. The HDMI interface of the AD9388A allows

for authentication of a video receiver, decryption of encoded

data at the receiver, and renewability of that authentication

during transmission as specified by the HDCP 1.3 protocol.

The HDMI receiver also offers advanced audio functionality.

The receiver contains an audio mute controller that can detect a

variety of selectable conditions that may result in audible

extraneous noise in the audio output. Upon detection of these

conditions, the audio data can be ramped to prevent audio

clicks and pops.

COMPONENT PROCESSOR (CP)

The CP is capable of decoding and digitizing a wide range of

component video formats in any color space. Component video

standards supported by the CP include 525i, 625i, 525p, 625p,

720p, 1080i, 1080p, 1250i, VGA up to UXGA at 60 Hz, and

many other standards.

The CP section of the AD9388A contains an AGC block. This

block is followed by a digital clamp circuit that ensures that the

video signal is clamped to the correct blanking level. Automatic

adjustments within the CP include gain (contrast) and offset

(brightness); however, manual adjustment controls are also

supported. If no embedded synchronization is present, the

video gain can be set manually.

A fully programmable, any-to-any 3 × 3 color-space converter is

placed before the CP section. This enables YPrPb-to-RGB and

RGB-to-YCrCb conversions. Many other standards of color

space can be implemented using the color-space converter.

A second fully programmable, any-to-any 3 × 3 color space

converter is placed in the back end of the CP core. This color

space converter features advanced color controls such as

contrast, saturation, brightness, and hue controls.

The output section of the CP can be configured in single data

rate (SDR) mode with one data packet per clock cycle. In SDR

mode, a 16-/20-bit 4:2:2 or 24-/30-bit 4:4:4 output is possible. In

these modes, HS/CS, VS/FIELD, and DE/FIELD (where

applicable) timing reference signals are provided.

The CP section contains circuitry to enable the detection of

Macrovision-encoded YPrPb signals for 525i, 625i, 525p, and

625p. It is designed to be fully robust when decoding these

types of signals.

VBI DATA PROCESSOR

VBI extraction of CGMS data is performed by the VBI data

processor (VDP) section of the AD9388A for interlaced,

progressive, and high definition scanning rates. The data

extracted is read back over the I2C interface.

For more detailed product information about the AD9388A,

send an e-mail to video.products@analog.com or contact a local

Analog Devices sales representative.

AD9388ABSTZ-5P Datasheet(PDF) 17 Page - Analog Devices

AD9388ABSTZ-5P Datasheet(HTML) 17 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Datasheet Download

Link URL