
1
Features
Operating Supply Range 3.0V to 3.6V
Power Dissipation 200mW Max
Low-Power Sleep Mode < 0.5mW
Four High-Speed, Low Noise 3.1K
, 4.15K
or 11.7K
Transimpedance (TZ) Amplifiers
Programmable Voltage Amplifiers Following
Fast TZ Amps (0.5, 0.7, 1 and 2 V/V)
Dedicated Differential RF Output
Flexible Output Configuration for Fast Quad Signals
Photodetector Signal Current up to 30
μ
A per Photodiode Allowed
(Read Mode), 4.15K
Transimpedance, PGC = 1 V/V
Gain Reduction on all Transimpedance Amplifiers During Write Mode
(Expanded Input Range 10X)
Separate Write Mode and ID Mode Pins for Fast Switching Between
Write and Read, and ID and Read
Transimpedance Amplifiers for EF and Laser Power Monitor
(3X Gain of High-Speed Amplifiers)
Programmable Offset DACs for Fast/Slow-Transimpedance Amplifiers
Serial Register for Programming Offset and Gains
Ideal for use with Atmel’s AT78C1503 DVD/CD Read Channel and
AT78C1502 DVD/CD DSP Servo Chip
Description
Atmel’s AT78C1505 contains the necessary preamplifiers for DVD or CD front-end
read electronics. The AT78C1505 is a DVD/CD preamp responsible for amplification
of slow/fast photodetector signals for CD-ROM, DVD-ROM or DVD-RAM data. The
preamp also includes an additional single-ended transimpedance amplifier with
programmable gain and offset adjustment which can be used for laser power monitor.
The CMOS preamplifier operates from a single 3.3V supply and is fully programmable
through a serial interface for either CD or DVD modes.
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
NC
A
GNDA
B
GNDB
C
GNDC
D
GNDD
NC
NC
VDD2
AP
AN
VDDB
BP
BN
VDDC
CP
CN
VDDD
DP
DN
NC
4
4
4
4
4
4
4
4
4
3
3
3
1
1
1
1
1
1
1
2
2
2
2
2
V
E
F
L
E
F
L
W
I
S
S
S
N
V
V
V
T
T
V
R
R
V
V
V
AT78C1505
DVD/CD Read
Preamplifier
AT78C1505
Preliminary
Rev. 1215A–11/98