ADV7181BST View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

ADV7181BST

Multiformat SDTV Video Decoder

Analog Devices 

ADV7181

INTRODUCTION

The ADV7181 is a high quality, single chip, multiformat video

decoder that automatically detects and converts PAL, NTSC,

and SECAM standards in the form of composite, S-Video, and

component video into a digital ITU-R BT.656 format.

The advanced and highly flexible digital output interface

enables performance video decoding and conversion in line

locked clock based systems. This makes the device ideally suited

for a broad range of applications with diverse analog video

characteristics, including tape based sources, broadcast sources,

security/surveillance cameras, and professional systems.

ANALOG FRONT END

The ADV7181 analog front-end comprises three 9-bit ADCs

that digitize the analog video signal before applying it to the

standard definition processor. The analog front end employs

differential channels to each ADC to ensure high performance

in mixed-signal applications.

The front end also includes a 6-channel input mux that enables

multiple video signals to be applied to the ADV7181. 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 within the ADV7181. The

ADCs are configured to run in 4× oversampling mode.

STANDARD DEFINITION PROCESSOR

The ADV7181 is capable of decoding a large selection of

baseband video signals in composite, S-Video, and component

formats. The video standards supported by the SDP include

PAL B/D/I/G/H, PAL60, PAL M, PAL N, PAL Nc, NTSC M/J,

NTSC 4.43, and SECAM B/D/G/K/L. The ADV7181 can

automatically detect the video standard and process it

accordingly.

The ADV7181 has a 5-line, superadaptive, 2D comb filter that

gives superior chrominance and luminance separation when

decoding a composite video signal. This highly adaptive filter

automatically adjusts its processing mode according to video

standard and signal quality with no user intervention required.

Video user controls such as brightness, contrast, saturation, and

hue are also available within the ADV7181.

The ADV7181 implements a patented adaptive digital line-

length tracking (ADLLT) algorithm to track varying video line

lengths from sources such as a VCR. ADLLT enables the

ADV7181 to track and decode poor quality video sources such

as VCRs, noisy sources from tuner outputs, VCD players, and

camcorders. The ADV7181 contains a chroma transient

improvement (CTI) processor that sharpens the edge rate of

chroma transitions, resulting in sharper vertical transitions.

The SDP can process a variety of VBI data services such as

closed captioning (CC), wide screen signaling (WSS), copy

generation management system (CGMS), EDTV, Gemstar

1×/2×, and extended data service (XDS). The ADV7181 is fully

Macrovision certified; detection circuitry enables Type I, II, and

III protection levels to be identified and reported to the user.

The decoder is also fully robust to all Macrovision signal inputs.

Rev. A | Page 4 of 104

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