Rainbow Electronics MAX3737 User Manual
General Description
The MAX3737 is a +3.3V laser driver designed for
multirate transceiver modules with data rates from
155Mbps to 2.7Gbps. Lasers can be DC-coupled to the
MAX3737 for reduced component count and ease of
multirate operation.
Laser extinction ratio control (ERC) combines the features
of automatic power control (APC), modulation compensation, and built-in thermal compensation. The APC loop
maintains constant average optical power. Modulation
compensation increases the modulation current in proportion to the bias current. These control loops combined
with thermal compensation maintain a constant optical
extinction ratio over temperature and lifetime.
The MAX3737 accepts differential data input signals.
The wide 5mA to 60mA (up to 85mA AC-coupled) modulation current range and up to 100mA bias current
range makes the MAX3737 ideal for driving FP/DFB
lasers in fiber-optic modules. External resistors set the
required laser current levels. The MAX3737 provides
transmit disable control (TX_DISABLE), single-point
fault tolerance, bias-current monitoring, modulation-current monitoring, and photocurrent monitoring. The
device also offers a latched failure output (TX_FAULT)
to indicate faults, such as when the APC loop is no
longer able to maintain the average optical power at the
required level. The MAX3737 is compliant with the SFF8472 transmitter diagnostic and SFP MSA timing
requirements.
The MAX3737 is offered in a 5mm x 5mm 32-pin thin QFN
and QFN package and operates over the -40°C to +85°C
extended temperature range.
Applications
Multirate OC-3 to OC-48 FEC Transceivers
Gigabit Ethernet SFF/SFP and GBIC
Transceivers
1Gbps/2Gbps Fibre Channel SFF/SFP and GBIC
Transceivers
Features
♦ Single +3.3V Power Supply
♦ 47mA Power-Supply Current
♦ 85mA Modulation Current
♦ 100mA Bias Current
♦ Automatic Power Control (APC)
♦ Modulation Compensation
♦ On-Chip Temperature Compensation
♦ Self-Biased Inputs for AC-Coupling
♦ Ground-Referenced Current Monitors
♦ Laser Safety, Shutdown, and Alarm Outputs
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
________________________________________________________________ Maxim Integrated Products 1
Pin Configurations
Ordering Information
19-2818; Rev 0; 4/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
Functional Diagram and Typical Application Circuit appear
at end of data sheet.
Pin Configurations continued at end of data sheet.
PART TEMP RANGE PIN-PACKAGE
MAX3737ETJ -40°C to +85°C 32 Thin QFN
MAX3737EGJ -40°C to +85°C 32 QFN
TOP VIEW
APCFILT2
APCSET
28
27
13
14
VBS
SHUTDOWN
APCFILT1
25 VMD
26
16GND
15
GND
24 MD
23
22
21
20
19
18
17
TX_DISABLE
V
V
PC_MON
BC_MON
IN+
MODTCOMP
TH_TEMP
MODBCOMP
MODSET
32
31
30
29
1GND
2
3
CC
4
9
10
GND
MC_MON
MAX3737EGJ
11
12
CC
V
TX_FAULT
5mm x 5mm
QFN
5
IN-
6
CC
7
8
V
CC
OUT+
OUT+
OUT-
OUT-
V
CC
BIAS
*THE EXPOSED PADDLE MUST BE SOLDERED TO SUPPLY GROUND
TO ACHIEVE SPECIFIED PERFORMANCE.
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= +2.97V to +3.63V, TA = -40°C to +85°C. Typical values are at VCC= +3.3V, I
BIAS
= 60mA, I
MOD
= 60mA, TA = +25°C, unless
otherwise noted.) (Notes 1, 2)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Supply Voltage VCC...............................................-0.5V to +6.0V
IN+, IN-, TX_DISABLE, TX_FAULT, SHUTDOWN,
MC_MON, BC_MON, PC_MON, VBS, VMD,
APCFILT1, APCFILT2, MD, TH_TEMP,
MODTCOMP, MODBCOMP, MODSET, and
APCSET Voltage .......................................-0.5V to V
CC
+ 0.5V
OUT+, OUT-, BIAS Current.............................-20mA to +150mA
Continuous Power Dissipation (T
A
= +85°C)
32-Pin QFN (derate 21.2mW/°C above +85°C) ...............1.3W
Operating Junction Temperature Range...........-55°C to +150°C
Storage Temperature Range .............................-55°C to +150°C
POWER SUPPLY
Supply Current I
Power-Supply Noise Rejection PSNR f ≤ 1MHz, 100mV
I/O SPECIFICATIONS
Differential Input Swing V
Common-Mode Input V
LASER BIAS
Bias-Current Setting Range 1 100 mA
Bias Off Current TX_DISABLE = high 0.1 mA
Bias-Current Monitor Ratio I
LASER MODULATION
Modulation-Current Setting
Range
Output Edge Speed
Output Overshoot/Undershoot (Note 7) ±6 %
Random Jitter (Notes 6, 7) 0.65 1.3 ps
Deterministic Jitter (Notes 6, 8)
Modulation-Current Temperature
Stability
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CC
I
MOD
CM
(Note 3) 47 60 mA
DC-coupled, Figure 1 0.2 2.4 V
ID
BIAS/IBC_MON
(Note 5) 5 85 mA
20% to 80%
(Notes 6, 7)
2.7Gbps
1.25Gbps
622Mbps
155Mbps
(Note 6) ±150 ±480 ppm/°C
(Notes 4, 6) 33 dB
P-P
5mA ≤ I
10mA < I
5mA ≤ I
10mA < I
5mA ≤ I
10mA < I
5mA ≤ I
10mA < I
5mA ≤ I
10mA < I
≤ 10mA 71 80
MOD
≤ 85mA 52 80
MOD
≤ 10mA 25.6 40
MOD
≤ 85mA 16 40
MOD
≤ 10mA 32 41
MOD
≤ 85mA 15 41
MOD
≤ 10mA 39 46
MOD
≤ 85mA 21 46
MOD
≤ 10mA 65 100
MOD
≤ 85mA 46 70
MOD
V
-
1.7
68 82 95 mA/mA
CC
/4
V
ID
ps
P-P
V
ps
P-P
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +2.97V to +3.63V, TA = -40°C to +85°C. Typical values are at VCC= +3.3V, I
BIAS
= 60mA, I
MOD
= 60mA, TA = +25°C, unless
otherwise noted.) (Notes 1, 2)
Note 1: AC characterization is performed using the circuit in Figure 2 using a PRBS 2
23
- 1 or equivalent test pattern.
Note 2: Specifications at -40°C are guaranteed by design and characterization.
Note 3: Excluding I
BIAS
and I
MOD
. Input data is AC-coupled. TX_FAULT open, SHUTDOWN open.
Note 4: Power-supply noise rejection (PSNR) = 20log
10(Vnoise (on VCC)
/∆V
OUT
). V
OUT
is the voltage across the 15Ω load when IN+ is high.
Note 5: The minimum required voltage at the OUT+ and OUT- pins is +0.75V.
Note 6: Guaranteed by design and characterization.
Note 7: Tested with 00001111 pattern at 2.7Gbps.
Note 8: DJ includes pulse-width distortion (PWD).
_______________________________________________________________________________________ 3
Modulation-Current Setting Error
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
5mA ≤ I
10mA < I
MOD
MOD
15Ω load,
T
= +25°C
A
Modulation Off Current TX_DISABLE = high 0.1 mA
Modulation-Current Monitor Ratio I
MOD/IMC_MON
EXTINCTION RATIO CONTROLS
M oni tor - D i od e Inp ut C ur r ent Rang eIMDAverage current into the MD pin 18 1500 µA
MD Pin Voltage 1.4 V
MD-Current Monitor Ratio IMD/I
APC Loop Time Constant C
PC_MON
APC_FILT
= 0.01µF, ∆IMD/∆I
BIAS
APC Setting Stability ±100 ±480 ppm/°C
APC Setting Accuracy TA = +25°C ±15 %
I
Compensation Setting
MOD
Range by Bias
I
Compensation Setting
MOD
Range by Temperature
Threshold Setting Range for
Temperature Compensation
K K = ∆I
TC TC = ∆I
T
TH
(Note 6) 10 60 °C
/∆I
MOD
BIAS
/∆Τ (Note 6) 0 1.0 mA/°C
MOD
LASER SAFETY AND CONTROL
Bias and Modulation Turn-Off
Delay
Bias and Modulation Turn-On
Delay
Threshold Voltage at Monitor Pins V
REF
C
APC_FILT
= 0.01µF, ∆IMD/∆I
BIAS
(Note 6)
C
APC_FILT
= 0.01µF, ∆IMD/∆I
BIAS
(Note 6)
Figure 5 1.14 1.3 1.39 V
INTERFACE SIGNALS
TX_DISABLE Input High V
TX_DISABLE Input Low V
TX_DISABLE Input Current
LO
HI
R
= 7.5kΩ 0.8 V
PULL
V
= V
HI
CC
= GND -450 -800
V
LO
TX_FAULT Output Low Sinking 1mA, open collector 0.4 V
Shutdown Output High Sourcing 100µA
Shutdown Output Low Sinking 100µA 0.4 V
≤ 10mA ±20
≤ 85mA ±15
%
223 262 302 mA/mA
0.85 1.0 1.15 mA/mA
= 1/70 3.3 µs
0 1.5 mA/mA
= 1/80
= 1/80
5µs
600 µs
2.0 V
15
V
-
CC
µA
0.4
V
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC= +3.3V, C
APC
= 0.01µF, I
BIAS
= 20mA, I
MOD
= 30mA, TA = +25°C, unless otherwise noted.)
OPTICAL EYE DIAGRAM
(2.7Gbps, 2
7
- 1PRBS, 2.3GHz FILTER)
MAX3737 toc01
54ps/div
1310nm FP LASER
E
r
= 8.2dB
OPTICAL EYE DIAGRAM
(1.25Gbps, 2
7
- 1PRBS, 940MHz FILTER)
MAX3737 toc02
116ps/div
1310nm FP LASER
E
r
= 8.2dB
OPTICAL EYE DIAGRAM
(155Mbps, 2
7
- 1PRBS, 117MHz FILTER, C
APC
= 0.1µF)
MAX3737 toc03
920ps/div
ELECTRICAL EYE DIAGRAM
(I
MOD
= 30mA, 2.7Gbps, 27 - 1PRBS)
MAX3737 toc04
52ps/div
75mV/div
SUPPLY CURRENT (ICC) vs. TEMPERATURE
(EXCLUDES BIAS AND MODULATION CURRENTS)
MAX3737 toc05
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
60
40
20
0-20
40
45
50
55
60
65
35
-40 80
VCC = 3.63V
VCC = 2.97V
VCC = 3.3V
I
MOD
= 60mA
I
BIAS
= 60mA
BIAS-CURRENT MONITOR GAIN
vs. TEMPERATURE
MAX3737 toc06
TEMPERATURE (°C)
I
BIAS
/I
BC_MON
(mA/mA)
603510-15
72
74
76
78
80
82
84
86
88
90
70
-40 85
PHOTO-CURRENT MONITOR GAIN
vs. TEMPERATURE
MAX3737 toc07
TEMPERATURE (°C)
I
MD
/I
PC_MON
(mA/mA)
6035-15 10
0.85
0.90
0.95
1.00
1.05
1.10
1.15
1.20
0.80
-40 85
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
200
230
220
210
240
250
260
270
280
290
300
-40 10-15 35 60 85
MODULATION-CURRENT MONITOR GAIN
vs. TEMPERATURE
MAX3737 toc08
TEMPERATURE (°C)
I
MOD
/I
MC_MON
(mA/mA)
90
0
1 10 100
MODULATION CURRENT
vs. R
MODSET
20
10
MAX3737 toc09
R
MODSET
(kΩ)
I
MOD
(mA)
40
30
60
70
50
80
0
15
10
5
20
25
30
35
40
45
50
02010 30 5040 70 8060 90
DETERMINISTIC JITTER
vs. MODULATION CURRENT
MAX3737 toc11
I
MOD
(mA)
DJ
(ps
P-P
)
0
0.5
1.0
1.5
2.0
0 20 40 60 80 100
RANDOM JITTER
vs. MODULATION CURRENT
MAX3737 toc12
I
MOD
(mA)
RJ
(ps
RMS
)
10
0.01
0 0.1 100
COMPENSATION (K)
vs. R
MODBCOMP
0.1
1
MAX3737 toc13
R
MODBCOMP
(kΩ)
K
(mA/mA)
110
30
50
40
60
70
80
90
100
-20 200 40 60 80 100
TEMPERATURE COMPENSATION
vs. R
TH_TEMP
(R
MODCOMP
= 500Ω)
MAX3737 toc14
TEMPERATURE (°C)
I
MOD
(mA)
R
TH_TEMP
= 12kΩ
R
TH_TEMP
= 7kΩ
R
TH_TEMP
= 4kΩ
R
TH_TEMP
= 2kΩ
Typical Operating Characteristics (continued)
(VCC= +3.3V, C
APC
= 0.01µF, I
BIAS
= 20mA, I
MOD
= 30mA, TA = +25°C, unless otherwise noted.)
1.6
0
0.1 10 100
PHOTODIODE CURRENT
vs. R
APCSET
0.4
0.2
0.6
0.8
1.0
1.2
1.4
MAX3737 toc10
R
APCSET
(kΩ)
I
MD
(mA)
1
_______________________________________________________________________________________ 5
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VCC= +3.3V, C
APC
= 0.01µF, I
BIAS
= 20mA, I
MOD
= 30mA, TA = +25°C, unless otherwise noted.)
30
32
34
36
38
40
42
44
-20 200 406080100
TEMPERATURE COMPENSATION
vs. R
TH_TEMP
(R
MODTCOMP
= 10kΩ)
MAX3737 toc15
TEMPERATURE (°C)
I
MOD
(mA)
R
TH_TEMP
= 12kΩ
R
TH_TEMP
= 7kΩ
R
TH_TEMP
= 4kΩ
R
TH_TEMP
= 2kΩ
20ms/div
HOT PLUG WITH TX_DISABLE LOW
V
CC
FAULT
MAX3737 toc16
TX_DISABLE
LASER
OUTPUT
t_init = 60ms
3.3V
0V
LOW
LOW
20
µs/div
TRANSMITTER ENABLE
V
CC
FAULT
MAX3737 toc17
TX_DISABLE
LASER
OUTPUT
t_on = 75µs
3.3V
LOW
HIGH
LOW
40ns/div
TRANSMITTER DISABLE
V
CC
FAULT
MAX3737 toc18
TX_DISABLE
LASER
OUTPUT
3.3V
LOW
LOW
t_off = 134ns
HIGH
1µs/div
RESPONSE TO FAULT
V
PC_MON
FAULT
MAX3737 toc19
TX_DISABLE
LASER
OUTPUT
t_fault = 0.9µs
HIGH
EXTERNALLY
FORCED FAULT
LOW
LOW
100ms/div
FAULT RECOVERY TIME
V
PC_MON
FAULT
MAX3737 toc20
TX_DISABLE
LASER
OUTPUT
t_init = 68ms
LOW
EXTERNAL FAULT
REMOVED
LOW
HIGH
HIGH
LOW
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