Optical Pickup Chipset Achieves the Industry’s Fastest CD-R/RW Write Speed
CXA2660N/CXA2663N
CXA2652EM/AEM/BEM
The increases in CD-R write speeds have been phenom-
enal and currently rival playback speeds.
Sony has now developed both a photodetector IC (PDIC)
that achieves the industry’s fastest write speed and an IC
that monitors the laser power during write operations by
taking maximum advantage of the process technologies
of which Sony is so proud.
These ICs, which provide the top performance level in
the industry, enable the implementation of CD-R/RW
optical pickups with the industry’s highest write speed.
CXA2660N/CXA2663N
RF/Servo PDIC
s
s
s
s
Supports high-speed CD-R writing
Built-in WRF output function: CXA2660N
Built-in gain switching function (8 dB): CXA2663N
Miniature transparent 14-pin molded package
(Straight lead and surface mounting packages)
CXA2652EM/AEM/BEM
Laser Front Monitor
s
s
s
Built-in chip capacitors (1005)
Photodetectors in a wide range of sizes
Miniature 6-pin side through hole COB package
CXA2660N
The CXA2660N is a photodetector IC
(PDIC) that detects the light reflected from
the disc. This device provides pulse
response characteristics (see table 1) that
allow applications to achieve high-speed
write operations. One feature of this
device is that in addition to an RRF output
pin used for RD signal detection during
playback, it also provides a WRF output
pin used for laser power detection during
writing. To improve the FPC (flexible
printed circuit) transmission characteris-
tics, this device is provided with a limiter
function for amplitude limitation for each
servo signal. It is provided in a miniature
transparent 14-pin molded package (in
both straight lead and surface mounting
versions) and has a structure that can with-
stand reflow soldering (under stipulated
conditions).
CXA2652EM/AEM/BEM
The CXA2652 Series products are photo-
detectors (front monitors) that are used to
monitor the laser power during write op-
erations. Since these devices include a
built-in I-V amplifier, they have a low
output impedance and provide a stable
output. They are provided in a 6-pin side
through hole miniature COB (chip-on-
board) package (3.2 mm
×
4.5 mm). A chip
capacitor (1005) is included within the
package making these devices optimal for
optical pickups, which have limited
mounting space.
CXA2663N
Like the CXA2660N, the CXA2663N is
a PDIC that detects light reflected from
the disc and provides pulse response
characteristics (see table 1) that allow
applications to achieve high-speed write
operations. This device inherits the gain
switching function from the CXA2636N
and CXA2637N, and can both prevent
output voltage saturation during high-
speed writing as well as prevent signal-
to-noise ratio degradation in playback
mode. This device is also provided in a
miniature transparent 14-pin molded pack-
age (in both straight lead and surface
mounting versions) and has a structure that
can withstand reflow soldering (under
stipulated conditions).
V
O
I
C
E
We had to work around the clock
for each IC in this chip set to cre-
ate this truly “sleepless” optical
pickup chip set, which supports
the industry’s fastest CD-R drives.
We reviewed Sony’s previously
developed technologies down to
the last detail to achieve the high-
est speeds possible. I strongly rec-
ommend that you put this chipset
in your next product’s “laser spot-
light.”
Disc
Objective
lens
13
0
13
30
0
30
C
13
0
D
Beam spliter
Grating
CXA2652EM/AEM/BEM
G
H
A
B
F
E
45 deg.
Laser diode
0
16
Top view
CXA2660N/2663N
∗
The photodetector pattern of the CXA2663N is identical to
that of the earlier product, the CXA2637N.
s
Figure 1 Optical Pickup Structure
s
Figure 3 CXA2660N Photodetector Pattern Dimensions
900
Ω
Vcc
1
14
GND
Vcc
1
6
V
OUT
0.1
µF
h
H
2
g
13
×3
1.2k
V
LIM
A'
a
d
V
LIM
D'
×3
1.2k
12
G
Vc
200
Ω
2
5
0.1
µF
GND
3
4.4 kΩ
4
V
IN
VR
IV
OUT
A
3
×3
1.2k
V
LIM
B'
b
c
V
LIM
C'
×3
1.2k
11
D
Photodiode
B
4
×3
1.2k
V
LIM
f
e
V
LIM
×3
1.2k
10
C
s
Figure 4 CXA2652EN/AEN/BEN Block Diagram
F
5
×3
1.2k
V
LIM
V
LIM
A
B
C
D
×3
1.2k
×1
9
E
Vc
6
RRF
s
Table 1
CXA2660N and CXA2663N Pulse Response
Characteristics
Slew rate
Settling
12 ns for a 1.9 V amplitude
10 ns for a 1.5 V amplitude
400 V/µs
350 V/µs
RRF = A + B + C + D
100k
V
LIM
7
WRF = (A' + B' + C' + D')
×
0.2625
A'
B'
C'
D'
×0.2625
8
WRF
CXA2660N
CXA2663N
*
The block diagram of the CXA2663N is identical to that of
the earlier product, the CXA2637N.
s
Table 2
CXA2652EN/AEN/BEN Photodetector Pattern
Dimensions (diameter)
0.70 mm
0.36 mm
0.47 mm
s
Figure 2 CXA2660N Block Diagram
CXA2652EM
CXA2652AEM
CXA2652BEM
