19-3116; Rev 2; 9/10
3.2Gbps, Low-Power, Compact,
SFP Laser Driver
General Description
The MAX3736 is a compact, +3.3V multirate laser driver
for SFP/SFF applications up to 3.2Gbps. The device
accepts differential data and provides bias and modula-
tion currents for driving a laser. DC-coupling to the laser
allows for multirate applications, and reduces the num-
ber of external components.
The wide 5mA to 60mA (85mA AC-coupled) modulation
current range and 1mA to 100mA bias current make the
MAX3736 ideal for driving FP/DFB laser diodes in fiber-
optic modules. The laser current setting can be con-
trolled by a current DAC, a voltage DAC, or a resistor.
Very low power dissipation, small package size, and
reduced component count, make this part an ideal solu-
tion for SFP-module applications.
The MAX3736 is available in a small 3mm x 3mm, 16-pin
thin QFN package. It operates over a -40°C to +85°C
temperature range.
Features
♦
Fully Compatible with SFP and SFF-8472
Specifications
♦
Programmable Modulation Current from 5mA to
60mA (DC-Coupled)
♦
Programmable Modulation Current from 5mA to
85mA (AC-Coupled)
♦
Programmable Bias Current from 1mA to 100mA
♦
56ps Edge Transition Times
♦
22mA (typ) Power-Supply Current
♦
Multirate Operation Up to 3.2Gbps
♦
On-Chip Pullup Resistor for DIS
♦
16-Pin, 3mm
×
3mm Thin QFN Package
MAX3736
Ordering Information
PART
MAX3736ETE
MAX3736ETE+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 Thin QFN-EP*
16 Thin QFN-EP*
Applications
Gigabit Ethernet SFP/SFF Transceiver Modules
1G/2G Fibre-Channel SFP/SFF Transceiver
Modules
Multirate OC-3 to OC-48 FEC SFP/SFF
Transceiver Modules
10G Ethernet LX-4 Modules
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Pin Configuration appears at end of data sheet.
Typical Application Circuit
HOST BOARD
HOST FILTER
VCC_RX
V
CC
SUPPLY FILTER
15Ω
56Ω
0.01μF
SFP OPTICAL TRANSMITTER
+3.3V
0.1μF
50Ω
SERDES
50Ω
0.1μF
IN-
BC_MON
IN+
OUT-
8.2pF
10Ω
MAX3736
MODSET
BIASSET
OUT+
BIAS
FERRITE
BEAD
GND
TX_DISABLE
MOD-DEF1
MOD-DEF2
DIS
LASER CONTROLLER
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
3.2Gbps, Low-Power, Compact,
SFP Laser Driver
MAX3736
ABSOLUTE MAXIMUM RATINGS
Power-Supply Voltage V
CC
..................................-0.5V to +6.0V
Voltage at IN+, IN-, DIS…..…………………-0.5V to (V
CC
+ 0.5V)
Voltage at BC_MON, MODSET, BIASSET .............-0.5V to +3.0V
Voltage at OUT+, OUT-.……………………+0.5V to (V
CC
+ 1.5V)
Voltage at BIAS ............……………………+0.5V to (V
CC
+ 0.5V)
Current into BIAS, OUT+, OUT- ......................-20mA to +150mA
Current into IN+, IN-......…………………………-20mA to +20mA
Continuous Power Dissipation (T
A
= +85°C)
16-Pin Thin QFN (derate 25mW/°C above +85°C) .............2W
Operating Junction Temperature Range ..........-55°C to +150°C
Storage Temperature Range .............................-55°C to +150°C
Die Attach Temperature ..................................................+400°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
Lead(Pb)-free...............................................................+260°C
Containing lead(Pb) .....................................................+240°C
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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +2.97V to +3.63V, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V, I
BIAS
= 20mA, I
MOD
= 30mA, T
A
= +25°C, unless
otherwise noted.) (Note 1)
PARAMETER
Power-Supply Current
I/O SPECIFICATIONS
Differential Input Voltage
Common-Mode Input Voltage
Differential Input Resistance
DIS Input Pullup Resistance
DIS Input Current
DIS Input High Voltage
DIS Input Low Voltage
BIAS GENERATOR
Bias Current Range
Bias Off-Current
BIASSET Current Gain
BIASSET Current Gain Stability
BIASSET Current Gain Linearity
Bias Overshoot
Bias-Current Monitor Gain
Bias-Current Monitor Gain
Stability (Notes 4, 5)
I
BIAS
I
BIASOFF
G
BIAS
Current into BIAS pin
Current into BIAS pin, DIS asserted high
(Note 3)
10mA
10mA
I
BIAS
I
BIAS
5mA
10mA
I
BIAS
I
BIAS
10mA
100mA
70
79
-4.4
-2.3
85
85
1
100
100
95
91
+4
+2.3
10
13.7
5mA
10mA
100mA
-7
-5
mA
μA
A/A
%
%
%
mA/A
+7
+5
%
V
IH
V
IL
V
ID
V
INCM
R
IN
R
PULL
V
DIS
= V
CC
V
DIS
= V
GND
, V
CC
= 3.3V, R
PULL
= 7.4k
2.0
0.8
-450
85
4.7
V
ID
= V
IN+
- V
IN-
, Figure 1
0.2
0.6
V
CC
100
7.2
115
10.0
15
k
μA
V
V
2.4
V
P-P
V
SYMBOL
I
CC
CONDITIONS
Excludes the laser bias and modulation
currents (Note 2)
MIN
TYP
22
MAX
35
UNITS
mA
100mA (Note 4)
100mA (Note 5)
During SFP module hot plugging;
see Figure 3 (Notes 5, 6)
(Note 5)
1mA
5mA
10mA
I
BIAS
I
BIAS
I
BIAS
|
4
|
|
2.8
|
|
2.4
|
2
_______________________________________________________________________________________
3.2Gbps, Low-Power, Compact,
SFP Laser Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.97V to +3.63V, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V, I
BIAS
= 20mA, I
MOD
= 30mA, T
A
= +25°C, unless
otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
Current into OUT+, R
L
= 15 ,
V
OUT+
and V
OUT-
0.6V (DC-coupled)
Current into OUT+, R
L
= 15 ,
V
OUT+
and V
OUT-
2.0V (AC-coupled)
5mA
10mA
I
MOD
I
MOD
I
MOD
I
MOD
10mA
85mA
MIN
5
5
TYP
MAX
60
mA
P-P
85
UNITS
MAX3736
Modulation Current Range
I
MOD
MODULATOR
Modulation Current Gain
Modulation Current Gain Stability
Modulation Current Gain Linearity
G
MOD
(Note 3)
10mA
10mA
70
79
-4.4
-3.3
2.3
0.1
0.1
0.1
0.1
60mA (Note 5)
60mA (Note 5)
48
58
16
17
30
6.3
0.6
1
ps
ps
RMS
1.4
1
1
1
100
I
MOD
I
MOD
80
80
38
38
ps
P-P
μA
ps
ps
%
85
85
95
91
+4
+3.3
A/A
%
%
85mA (Notes 4, 5)
85mA (Note 5)
I
BIASSET
= 0.15mA; I
MODSET
= 0.7mA
Bias Current Gain and
Modulation Current Gain
Matching (Notes 5, 7)
I
BIASSET
= I
MODSET
= 0.15mA
I
BIASSET
= I
MODSET
= 0.4mA
I
BIASSET
= I
MODSET
= 0.6mA
I
BIASSET
= I
MODSET
= 0.9mA
Modulation OFF Current
Rise Time
Fall Time
I
MODOFF
t
R
t
F
DIS asserted high
20% to 80%; 10mA
80% to 20%; 10mA
10mA I
MOD
2
23
-1 PRBS
10mA I
MOD
K28.5 pattern
10mA I
MOD
2
23
-1 PRBS
10mA I
MOD
T
A
= +100°C
Random Jitter
10mA
I
MOD
60mA; 2.67Gbps;
60mA; 3.2Gbps;
60mA; 155Mbps;
60mA; 3.2Gbps; K28.5;
60mA (Note 5)
Deterministic Jitter
(Notes 5, 8)
Note 1:
Specifications at -40°C are guaranteed by design and characterization.
Note 2:
Maximum value is specified at I
MOD
= 60mA and IBIAS = 100mA. BC_MON connected to V
CC
.
Note 3:
Modulation current gain, G
MOD
, is defined as G
MOD
= I
MOD
/ I
MODSET
. Bias current gain, G
BIAS
, is defined as G
BIAS
=
I
BIAS
/ I
BIASSET
. The nominal gain is measured at V
CC
= +3.3V and T
A
= +25°C.
Note 4:
Gain stability is defined as [(Gain) - (Nom_Gain)] / (Nom_Gain) over the listed current range, temperature, and supply
variation. Nominal gain is measured at V
CC
= +3.3V, T
A
= +25°C. The voltage at the BC_MON pin must not exceed 1.39V.
Note 5:
Guaranteed by design and characterization; see Figure 2.
Note 6:
V
CC
turn-on time must be less than 0.8s, DC-coupled interface.
Note 7:
The gain matching is defined as ABS [(G
MOD
/G
BIAS
- G
MODNOM
/G
BIASNOM
)/(G
MODNOM
/G
BIASNOM
)] over the specified
temperature and voltage supply range.
Note 8:
For supply noise tolerance, noise is added to the supply (100mV
P-P
) up to 2MHz; see Figure 3.
_______________________________________________________________________________________
3
3.2Gbps, Low-Power, Compact,
SFP Laser Driver
MAX3736
VOLTAGE
V
IN+
V
IN-
(V
IN+
) - (V
IN-
)
200mV
P-P
MIN
2400mV
P-P
MAX
CURRENT
I
OUT+
I
MOD
V
CC
100mV MIN
1200mV MAX
OUT-
30Ω
1.1pF
25Ω
26Ω
V
CC
MAX3736
OUT+
OSCILLOSCOPE
I
OUT+
130Ω
50Ω
Figure 1. Definition of Single-Ended Input Voltage Range
Figure 2. Output Termination for Characterization
SOURCE
NOISE
VOLTAGE
SUPPLY
HOST BOARD
FILTER DEFINED BY SFP MSA
1μH
0.1μF
10μF
0.1μF
MODULE
TO LASER
DRIVER V
CC
OPTIONAL
OPTIONAL
Figure 3. Supply Filter
Typical Operating Characteristics
(Typical values are at V
CC
= 3.3V, I
BIAS
= 20mA, I
MOD
= 30mA, T
A
= +25°C, unless otherwise noted.)
OPTICAL EYE
(155Mbps)
MAX3736 toc01
OPTICAL EYE
(2.488Gbps)
MAX3736 toc02
ELECTRICAL EYE
(2.488Gbps)
1870MHz FILTER
2
23
- 1 PRBS
MAX3736 toc03
117 MHz FILTER, 2
31
- 1 PRBS
1310nm FP LASER
E
R
= 8.2dB, OC-48 FILTER
2
31
- 1 PRBS, 1310 FP LASER
C4
919ps/div
58ps/div
58ps/div
4
_______________________________________________________________________________________
3.2Gbps, Low-Power, Compact,
SFP Laser Driver
Typical Operating Characteristics (continued)
(Typical values are at V
CC
= 3.3V, I
BIAS
= 20mA, I
MOD
= 30mA, T
A
= +25°C, unless otherwise noted.)
MAX3736
SUPPLY CURRENT vs. TEMPERATURE
MAX3736 toc05
BIAS CURRENT MONITOR GAIN
vs. TEMPERATURE
MAX3736 toc06
MODULATION CURRENT
vs. MODSET RESISTANCE (Z
L
= 15
Ω
)
70
60
I
MOD
(mA
P-P
)
MAX3736 toc07
80
EXCLUDES I
BIAS
AND I
MOD
70
SUPPLY CURRENT (mA)
60
20
80
18
GAIN (mA/A)
50
40
30
16
50
40
30
20
10
14
12
20
10
-40
-15
10
35
60
85
TEMPERATURE (°C)
10
-40
-15
10
35
60
85
TEMPERATURE (°C)
0
1
10
R
MODSET
(kΩ)
100
BIAS CURRENT vs. BIAS RESISTANCE
MAX3736 toc08
EDGE TRANSITION TIME
vs. MODULATION AMPLITUDE
MAX3736 toc09
100
90
80
70
I
BIAS
(mA)
60
50
40
30
20
10
0
1
10
R
BIASSET
(kΩ)
80
70
EDGE TRANSITION TIME (ps)
FALL TIME
60
50
40
30
20
10
RISE TIME
100
10
20
30
40
50
60
I
MOD
(mA)
_______________________________________________________________________________________
5
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