AT78C1503

Features:

• Operating Supply Range 3.0V to 3.6V
• Power Dissipation 1W Max
• Low-power Sleep Mode (<0.5 mW)
• RF Data Channel
Automatic Gain Control or Programmable Gain Mode
Wide Bandwidth VGA
VGA Accepts Inputs from 30300 mV Peak-to-peak Differential (PPD), 60600 mVPPD or 1101100 mVPPD
Programmable Equalization via 7th-order Equiripple Filter with Programmable Symmetric Zeros
Programmable 5-to-1 Filter Cutoff Range
Data Slicer with DC Restore Circuit
Wide Frequency Range Clock Extraction
Frequency Synthesizer with Independent 7-bit M and 6-bit N Dividers, Better than 1% Resolution
Highly Programmable to Accommodate DVD (15X) and CD (630X)
Write Asymmetry Measurement for Adjusting Write-mode Power
Data Recovery Supports CLV, ZCLV, ZCAV Recording
Optional Internally-generated Timing for AGC and Timing Recovery
• Synthesizer Functions
Supports Wobble Clock Synthesis, Using Low-jitter PLL
• Servo Algebra and OPC Functions
45 MHz Bandwidth for Differential Phase Tracking Detector
Land and Groove Detector for DVD RAM
Supports One Beam Push/Pull Tracking Output
Supports One Beam Differential Phase Tracking
Supports Three-beam Push/Pull Tracking Output, Using E, F, G, H
Focus Error Signal Output
Focus OK Signal
Track Crossing Detection
Mirror Signal Output
Wobble Detection for DVD RAM, DVD-RW, DVD-R
Detects Tracking Error OK
Provides Sample and Hold Functions for CD and DVD OPC
Formats Pre-pit Data, Using Raw Pre-pit Information from AT78C1503
• Header Detection for DVD RAM



Pinout




Description

The AT78C1503 is a programmable DVD/CD channel responsible for servo algebra, gain control, equalization, bit detection and clock extraction for CD-ROM, DVD-ROM, DVD-R, DVD-RW and DVD-RAM formats. Programmable fea-tures allow data rates up to 5X DVD. Also, for DVDRAM functionality, the channel serves the write path providing laser power control and pit asymmetry detection. Up to 2X DVD write speeds are supported for DVD-R, DVD-RW and DVDRAM. The extracted wobble frequency is supplied to the AT78C1507 companion chip which in turn synthesizes the write clock.

The AT78C1507is the companion chip to the AT78C1503 DVD/CD Read Channel and the AT78C1504 DVD/CD Automatic Laser Power Controller. Working in conjunction with the read channel, the AT78C1507 is responsible for wobble clock synthesis for DVD-R and DVD-RAM formats. In addition, the two parts working together also support pre-pit data and clock recovery for the DVD-R format. Four separate inputs are provided to enable the AT78C1507 to perform tracking servo algebra, using just the outrigger photo detector signals (E, F, G, H for example) coming from the OPU. This extends the range of supported tracking servo algebra functions for the 1503-1507 combina-tion. Lastly, OPC capability is supported for efficient writing of DVD-R, DVD-RAM and CD-R disks.

Based on CMOS technology, both the AT78C1503 and AT78C1507 operate from a single 3.3V supply and are fully programmable through serial interfaces for both CD and DVD modes.