1
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 mV
PPD
or 1101100 mV
PPD
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
Description
The AT78C1503 is a programmable DVD/CD channel responsible for servo algebra, gain con-
trol, equalization, bit detection and clock extraction for CD-ROM, DVD-ROM, DVD-R, DVD-RW
and DVD-RAM formats. Programmable features allow data rates up to 5X DVD. Also, for DVD-
RAM functionality, the channel serves the write path providing laser power control and pit asym-
metry detection. Up to 2X DVD write speeds are supported for DVD-R, DVD-RW and DVD-
RAM. The extracted wobble frequency is supplied to the AT78C1507 companion chip which in
turn synthesizes the write clock.
The AT78C1507 is 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 combination. 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.
DVD/CD Read
Channel
AT78C1503
AT78C1507
Rev. 2054ADVD07/02
5
DVD/CD Read Channel
2054ADVD07/02
12
FOHG
Digital Input
Focus High Gain
13
REXT
Passive
Passive for 0 TC Current Reference (16.5 K_, 1%)
14
VDD1
3.3V Supply
DPD, IBIAS
15
VSS1
0V Supply
DPD, IBIAS
16
FO1_CD
Analog Input
Focus 1, CD Input
17
FO2_CD
Analog Input
Focus 2, CD Input
18
TR1_CD
Analog Input
Track 1, CD Input
19
TR2_CD
Analog Input
Track 2, CD Input
20
VDD6
3.3V Supply
Slow Servo Analog
21
SS_H
Digital Input
Servo Sample and Hold
22
VSS6
0V Supply
Slow Servo Analog
23
REFFRONT
Input/Output
Servo Front-end Reference Level
24
REFBACK
Input/Output
Servo back-end Reference Level
25
LENSPOS
Analog Input
Lens Position Error Input
26
ATP1
Analog Output
Servo Analog Test Point
27
FE
Analog Output
Focus Error Output
28
TE
Analog Output
Tracking Error Output
29
SLOWSUM
Analog Output
Low-pass Filtered Sum of Photodetector Outputs
30
PORB
Digital Input
Power-on Reset, Bar (active-low)
31
VSS8
0V Supply
Servo DACs
32
VDD8
3.3V Supply
Servo DACs
33
IDSEL
Digital Input
ID Field Select
34
LHIPWR
Digital Input
Laser High Power
35
SHLD
Digital Input
Servo Hold
36
ADCSTRT
Digital Input
Start On-chip 6-bit ADC
37
BWUP
Digital Input
Bandwidth Up
38
BWDN
Digital Input
Bandwidth Down
39
IDINT
Digital Input
Mode Select of Sequencer
40
PD
Digital Input
Power-down
41
RG
Digital Input
User Data Read Gate
42
VSS9
0V Supply
Servo DAC Rings
43
VDD9
3.3V Supply
Servo DAC Rings
44
WOBBLE
Digital Output
Wobble Detect Output
45
ID12
Digital Output
ID Field 12 Detected
46
ID34
Digital Output
ID Field 34 Detected
47
TZC
Digital Output
Track Zero Crossing
Table 1. AT78C1503 Pin List (Continued)
Pin #
Pin Name
Type
Description
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