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Электронный компонент: A1751A

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A1751A DWDM Analog
Forward-Path or Return-Path Laser Modules
Data Sheet, Rev. 4
June 2001
Features
s
Higher temperature rating
s
Excellent linearity
s
Standard ITU wavelengths
s
Advanced analog chip design
s
Tested for forward and return path applications
s
Reduces equipment requirements in the hub
s
Exceeds
Telcordia Technologies
* 468 specifica-
tion.
Applications
s
Node capability
s
Narrow transmitter housing
s
Networks with limited fiber
s
Architectures using separate optical wavelengths
to carry targeted services
*
Telcordia Technologies
is a trademark of Telcordia Technologies,
Inc.
Description
The A1751A laser module is a dense wavelength-
division multiplexing (DWDM) laser for analog appli-
cations. It features a distributed-feedback (DFB) chip
that has been designed specifically for radio fre-
quency (RF) applications. The A1751A laser module
has a wide temperature range for reliable perfor-
mance in harsh node environments and narrow
transmitter designs. It also features low adiabatic
chirp to maximize signal quality in short and long
lengths of fiber. The laser's excellent inherent linear-
ity minimizes degradation of the broadcast signals
caused by the quadrature amplitude modulation
(QAM) channels.
Wavelength-division multiplexing is being designed
into cable television architectures. DWDM, a method
for delivering targeted QAM signals to different loca-
tions, allows multiple signal sets to be combined onto
a single strand of fiber for transmission from a head-
end to a hub. At the hub, individual QAM signals can
be selected and combined with broadcast analog
channels. The versatile A1751A DWDM laser module
reduces cable network architecture fiber needs and
lessens equipment requirements in the hub.
The A1751A is available in a wide range of standard
ITU wavelengths. The lasers are offered as either for-
ward-path (40 MHz--860 MHz) or return-path
(5 MHz--210 MHz) modules.
2
A1751A DWDM Analog
Data Sheet, Rev. 4
Forward-Path or Return-Path Laser Modules
June 2001
Agere Systems Inc.
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess
of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for extended
periods can adversely affect device reliability.
* The device can withstand continuous exposure to the specified limits without damage.
Characteristics
1. Tested in a 50
resistively matched system.
2. Eight channel loading with 10% OMI and 40 km fiber length.
3. Measured at 42 MHz.
4. Measured at 553.25 MHz, 577.25 MHz, and 595.25 MHz.
5. Change in wavelength as case temperature is changed.
Parameter*
Symbol
Min
Max
Unit
Operating Case Temperature Range
T
C
40
85
C
Storage Temperature Range
Tstg
40
85
C
Monitor Photodiode Reverse Voltage
V
MPD
--
10
V
Laser Forward Current
I
F
--
150
mA
Reverse Voltage (Laser)
V
R
--
2
V
TEC Current
I
TEC
--
1.7
A
RF Input Power
P
RFIN
--
62 dBm
V
Table 1. Key Characteristics
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Frequency Range:
1
Return Path
Forward Path
F --
5
40
--
--
210
860
MHz
MHz
MHz
Frequency Response:
1
5 MHz--210 MHz
40 MHz--860 MHz
--
I
F
= 60 mA,
T
OP
= 25 C
--
--
0.5
0.5
--
--
dB
dB
RF Return Loss:
1
5 MHz--210 MHz
40 MHz--860 MHz
RL
RF
I
F
= 60 mA,
--
--
>16
>16
--
--
dB
dB
Optical Output Power
P
O
I
F
= I
OP
6, 8, or
10
--
--
mW
Laser Relative Intensity
Noise
RIN
I
F
= I
TH
+ 70 mA,
T = 25 C
--
<
155
--
dB/Hz
Composite Second Order
2, 3
CSO
I
F
= I
OP
, OMI = 10%
--
--
50
dBc
Composite Triple Beat
2, 4
CTB
I
F
= I
OP
, OMI = 10%
--
--
60
dBc
Available Wavelengths
I
P
= I
OP
, T = T
OP
1527.94
--
1563.1
nm
Wavelength Drift
5
I
F
= 60 mA,
T = T
OP,
T
C
varied from min-->max
--
--
0.04 nm
Adiabatic Chirp
FM
I
F
= 60 mA,
T
OP
= 25 C,
measured at 500 MHz
40
--
100
MHz/mA
Operating Case
Temperature Range
T
C
I
F
= I
OP
40
--
85
C
3
Data Sheet, Rev. 4
A1751A DWDM Analog
June 2001
Forward-Path or Return-Path Laser Modules
Agere Systems Inc.
Characteristics
(continued)
1. Bias point at which all specifications apply.
2. For 10 mW output power. Minimum slope efficiency is lower for lower-power lasers.
3. Chip temperature at which wavelength specification is met. Operating chip temperature is reported for each laser.
Electrical Schematics
Figure 1. A1751A Laser Schematic
Table 2. Additional Characteristics
Parameter
Symbol
Conditions
Min
Max
Unit
Bias Current
1
I
B
BOL
--
120
mA
Threshold Current
I
TH
25 C, BOL
--
30
mA
Slope Efficiency
2
I
P
= I
TH
+ 20 and
I
TH
+ 60
0.10
--
mW/mA
Monitor Photocurrent
I
MON
I
OP
= 0 mA, V
RM
= 5 V,
T
OP
= 25 C
10
200
A/mW
Operating Chip Temperature
3
T
OP
I
F
= I
OP
18
35
C
TEC Current
I
TEC
40
C
<
T
C
<
85
C,
T
OP
= 15 C--35 C,
I
F
= 60 mA
1.5
1.5
A
TEC Voltage
V
TEC
T
OP
= 15 C--35 C over T
C
2.5
3.8
V
Thermistor Resistance
R
TH
T
OP
= 25 C
--
10.5
k
Optical Return Loss
RL
T
C
40
--
dB
Side Mode Suppression Ratio
SMSR
I
F
= I
OP
30
--
dB
1
2
3
4
5
6
7
14
13
12
11
10
9
8
CASE
GROUND
NC
(+)
()
(+)
()
TEC
()
(+)
CASE
GROUND
NC
ISOLATOR
(+)
1-1233(F)
4
A1751A DWDM Analog
Data Sheet, Rev. 4
Forward-Path or Return-Path Laser Modules
June 2001
Agere Systems Inc.
Electrical Schematics
(continued)
Figure 2. A1751A Circuit Schematic
1-1234(F)
1
2
3
4
5
6
7
14
13
12
11
10
9
8
THERMISTOR
TEC ()
MPC CATHODE
NC
THERMISTOR
dc LASER
BIAS
MPD ANODE
CASE GROUND
TEC (+)
CASE
GROUND
CASE
GROUND
MPC CATHODE
NC
LASER
COMMON (+)
LASER
MODULATION ()
LASER
COMMON (+)
39 nH
200
0.01
f
3.3
H
1000 pf
1000 pf
0.01
f
0.01
f
SEE
SEE
3A AND 3B
FIGURES
FIGURE 4
Figure 3a. Impedance-Matched Configuration
Figure 3b. Resistive-Matched Configuration
C7
1 pF--
0.01
f
0.01
f
VSWR
T1*
3:5
2
3
0.5 pF--2.5 pF
SEE PIN 12,
FIGURE 2
0.01
f
FREQUENCY
RESPONSE
*T1 (75
) 3:5.
5 pF
1-1238F.a
SEE PIN 12,
FIGURE 2
37.5
R1
37.5
R2
1-1238F.b
5
Data Sheet, Rev. 4
A1751A DWDM Analog
June 2001
Forward-Path or Return-Path Laser Modules
Agere Systems Inc.
Electrical Schematics
(continued)
Note: When ordering the dc set, the following boards are included: alarm board, 9108-004; TEC board, 9028-004; constant current, 9383-004.
Figure 4. dc Set (Agere Systems-Supplied Option)
CONSTANT
ALARM
TEC
J2
1 THERMISTOR
2 THERMISTOR
3 dc LASER BIAS
4 MPD ANODE (CASE GROUND)
5 MPC CATHODE
6 TEC (+)
7 TEC ()
8 GND
9 GND
10 GND
1
2
3
4
5
6
7
THERMISTOR
TEC ()
MPC CATHODE
THERMISTOR
dc LASER
BIAS
MPD ANODE
CASE GROUND
TEC (+)
MPC CATHODE
39 nH
200
0.01
f
3.3
H
1000 pf
1000 pf
0.01
f
0.01
f
1-1238F.c