1
Copyright 2002, Capella Microsystems, Inc.
399B West Trimble Road, San Jose, CA 95131 USA 408.382.6600 FAX.408.382.6601
P
REL
I
M
I
N
A
R
Y
P
ROD
U
C
T
D
AT
AS
HE
E
T
-- C
O
NF
ID
ENT
I
AL
CM1281
Integrated PD+TIAIC
DESCRIPTION
The CM1281 is a PDIC for use in
DVD-ROM/CD-ROM applications. The PDIC
is compatible with the CD laser diode
wavelength of 780nm. Four high speed
channels (A1/a1~A4/a4), two low speed
channels (E1~E2), and a high speed RF
channel. The PD pattern is designed to
handle DVD-ROM/CD-ROM media. In
addition the PD pattern is designed for
twin laser applications, with a switchable
PD pattern and gain.
FEATURES
Full CMOS seven channel, integrated high
speed photodiodes and current to voltage
transimpedance amplifiers.
High speed (55MHz typ) RF channel.
Four High Speed (55MHz typ) data channels
(A1/a1~A4/a4).
Two low speed tracking channels (E1, E2).
Can be used for reading DVD-ROM/CD-
ROM/CD-R/CD-RW optical media.
High PD sensitivity optimized for DVD/CD
applications with 650nm and 780nm laser
diodes.
APPLICATIONS
DVD-ROM / CD-ROM Drives
DISCLAIMER
Capella Microsystems Inc. reserves the right to make changes in specifications or discontinue this product at any time
without notice. Please contact Capella Microsystems Inc. for possible updates before starting a design.
Capella Microsystems Inc. products are not designed for use in life support applications. Any parties who use these products
in such applications do so at their own risk and agree to fully indemnify Capella Microsystems Inc. for any damages resulting
from such improper usage or sale.
Revision: 0.5
Date: 01-Oct-2002
CM1281 -- Integrated PD+TIAIC
2
Copyright 2002, Capella Microsystems, Inc.
P
REL
I
M
I
N
A
R
Y
P
ROD
U
C
T
D
AT
AS
HE
E
T
-- C
O
NF
ID
ENT
I
AL
Figure 1: CM1281 Block Diagram
CM1281 -- Integrated PD+TIAIC
3
Copyright 2002, Capella Microsystems, Inc.
P
REL
I
M
I
N
A
R
Y
P
ROD
U
C
T
D
AT
AS
HE
E
T
-- C
O
NF
ID
ENT
I
AL
Absolute Maximum Ratings
Description Symbol Value Unit
Power Supply Voltage
V
CC
6.0 V
Output Voltage
Vo
Vcc + 0.5
V
Storage Temperature
Tstg
-30 ~ +85
C
Soldering Temperature
Tsol
260
C
Recommended Operating Conditions
Table 1: CM1281 Pin Descriptions
Pin
No.
Pin
Signal
I/O Pin
Description
2 V
A1
/ V
a1
1 V
A2
/ V
a2
6 V
A3
/ V
a3
5 V
A4
/ V
a4
11 V
E1
7 V
E2
O
The optical input signal on respective photodiodes is converted to a voltage
at the output pins.
4 V
RF
O
RF output voltage represents the summing of the
A1/a1 ~ A4/a4 channel voltages.
3 SW I
Pattern Select Selects from 2 PD patterns (CD/DVD). A low level on this
input indicates DVD mode, a high level on this input indicates CD mode.
TTL/CMOS compatible input. Defaults to DVD mode if floating.
8, 12
GND
I
GND (Ground)
9 V
S
I
Reference voltage input pin provided by a stable external voltage source
(typically 2.1V).
10 V
CC
I
5V 10% DC Supply
Description Signal
Condition
Min.
Typ.
Max.
Unit
Operating Supply Voltage Range
V
CC
- 4.5
5.0
5.5
V
Operating Reference Voltage Range
V
S
-
1.9
2.1
2.3
V
Operating Temperature Range
Topr
-
-20
75
C
CM1281 -- Integrated PD+TIAIC
4
Copyright 2002, Capella Microsystems, Inc.
P
REL
I
M
I
N
A
R
Y
P
ROD
U
C
T
D
AT
AS
HE
E
T
-- C
O
NF
ID
ENT
I
AL
Electrical Characteristics
(Ta=25C, V
CC
=5V, V
S
=2.1V, R
L
=10K, C
L
=10pf)
Description
Symbol
Condition
Min. Typ. Max. Unit Applies
to
Current Consumption
I
CC
All output pins open
-
17
22
mA
V
CC
Output Offset Voltage 1
V
OD1
Offset voltage with respect
to Vs (Note 3)
-15 0 +15 mV
V
A1
~ V
A4,
V
a1
~ V
a4
Output Offset Voltage 2
V
OD2
Offset voltage with respect
to Vs (Note 3)
-15 0 +15 mV V
E1
~ V
E2
Output Offset Voltage 3
V
OD3
Offset voltage with respect
to GND (Note 3)
1.2 1.4 1.6 V
V
RF
(A1+A3)-(A2+A4) (Note 3) -25 0 +25
V
A1
~ V
A4,
V
a1
~ V
a4
(A1+A4)-(A2+A3) (Note 3) -25 0 +25
V
A1
~ V
A4,
V
a1
~ V
a4
(A1+A2)-(A3+A4) (Note 3) -25 0 +25
V
A1
~ V
A4,
V
a1
~ V
a4
Output Offset Voltage
Difference
V
OD
(E
2
-E
1
) (Note 3) -25
0
+25
mV
V
E1
~ V
E2
Maximum Output
Voltage
V
OH
3.8
-
-
V
V
A1
~ V
A4,
V
a1
~ V
a4,
V
E1
~ V
E2,
V
RF
SW Input High Level
V
IH
2.4 -
-
V
SW
SW Input Low Level
V
IL
-
- 0.8 V
SW
Pattern Switching
Settling Time
H
L
L
H (Note 4)
- - 10 s
Note 3: Dark conditions, which implies no light incident on the photodiode.
Note 4: Guaranteed by design.
CM1281 -- Integrated PD+TIAIC
5
Copyright 2002, Capella Microsystems, Inc.
P
REL
I
M
I
N
A
R
Y
P
ROD
U
C
T
D
AT
AS
HE
E
T
-- C
O
NF
ID
ENT
I
AL
DVD Mode (SW=L)
(Ta=25C, V
CC
=5V, V
S
=2.1V, R
L
=10K, C
L
=10pf, =650 nm)
Description
Symbol
Condition
Min. Typ. Max. Unit Applies
to
Sensitivity 1
R
P1
P
O
= 10W
23.0
27.0
31.0
mV/W
V
a1
~ V
a4
Sensitivity 3
R
P3
P
O
= 10W
40.9
47.5
55.2
mV/W
V
RF
Cutoff Frequency 1
f
C1
-3dB 45
55
-
MHz
V
a1
~ V
a4
Cutoff Frequency 3
f
C3
-3dB 45
55
-
MHz
V
RF
Group Delay Variation
t
GD
f = 1~27.5 MHz
-
1
3
ns
V
a1
~ V
a4
,
V
RF
Output Noise Level 1
V
N1
f = 1~27.5 MHz
RBW = 30 kHz
(Note 3)
- -81
-76
dBm
V
a1
~ V
a4
Output Noise Level 2
V
N2
f = 1~27.5 MHz
RBW = 30 kHz
(Note 3)
- -70
-65
dBm V
RF
CD Mode (SW=H)
(Ta=25C, V
CC
=5V, V
S
=2.1V, R
L
=10K, C
L
=10pf, =780 nm)
Description
Symbol
Condition
Min. Typ. Max. Unit Applies
to
Sensitivity 1
R
P1
P
O
= 10W
29.0
34.0
39.0
mV/W
V
A1
~ V
A4
Sensitivity 2
R
P2
P
O
= 10W
76.0
89.0
102.0
mV/W
V
E1
~ V
E2
Sensitivity 3
R
P3
P
O
= 10W
51.5
60.0
70.3
mV/W
V
RF
Cutoff Frequency 1
f
C1
-3dB 28
35
-
MHz
V
A4
~ V
A4
Cutoff Frequency 2
f
C2
-3dB 1
3
-
MHz
V
E1
~ V
E2
Cutoff Frequency 3
f
C3
-3dB 28
35
-
MHz
V
RF
Group Delay Variation
t
GD
f = 1~17 MHz
-
1
3
ns
V
A1
~ V
A4
V
RF
Output Noise Level 1
V
N1
f = 1~17 MHz
RBW = 30 kHz
(Note 3)
- -81
-76
dBm
V
A
~ V
A4
Output Noise Level 2
V
N2
f = 1~17 MHz
RBW = 30 kHz
(Note 3)
- -70
-65
dBm V
RF
Note 3: Dark conditions, which implies no light incident on the photodiode.
PDF 
ZIP