MAX3737ETJ+ Maxim Integrated Products, MAX3737ETJ+ Datasheet - Page 9

• Manufacturer Part Number: MAX3737ETJ+
• Description: IC LSR DRVR 2.7GBPS 3.63V 32TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driver (Fiber Optic)r

Specifications of MAX3737ETJ+

• Data Rate: 2.7Gbps
• Number Of Channels: 1
• Voltage - Supply: 2.97 V ~ 3.63 V
• Current - Supply: 47mA
• Current - Modulation: 85mA
• Current - Bias: 100mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-WFQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 4. Functional Diagram
Modulation compensation from bias increases the mod-
ulation current by a user-selected proportion (K) need-
ed to maintain peak-to-peak laser power as bias
current increases with temperature. Refer to Maxim
Application Note HFAN-02.2.1 for details:
This provides a first-order approximation of the current
increase needed to maintain peak-to-peak power. Slope
efficiency decreases more rapidly as temperature
increases. The MAX3737 provides additional tempera-
ture compensation as temperature increases past a
user-defined threshold (T
R
R
R
MC_MON
BC_MON
MDMON
TX_DISABLE
SHUTDOWN
TX_FAULT
MC_MON
PC_MON
BC_MON
IN+
IN-
_______________________________________________________________________________________
R
PULL
I
I
K
MOD
268
I
BIAS
MD
82
= 7.5kΩ
1
INPUT BUFFER
=
Multirate Laser Driver with Extinction
TH
∆
∆
).
I
I
R
MOD
BIAS
TH_TEMP
TH_TEMP
V
CC
SAFETY LOGIC
AND POWER
DETECTOR
T > T
H
T
R
MODTCOMP
MODTCOMP
DATA
PATH
I
I
MOD
BIAS
xTC
ENABLE
ENABLE
R
MODSET
MODSET
MAX3737
V
BG
x268
R
MODBCOMP
MODBCOMP
The safety circuitry contains a disable, input (TX_DIS-
ABLE), a latched fault output (TX_FAULT), and fault
detectors (Figure 5). This circuitry monitors the opera-
tion of the laser driver and forces a shutdown if a fault
is detected (Table 1). The TX_FAULT pin should be
pulled high with a 4.7kΩ to 10kΩ resistor to V
required by the SFP MSA. A single-point fault can be a
short to V
response to various single-point failures. The transmit
fault condition is latched until reset by a toggle of
TX_DISABLE or V
laser diode shutdown through the optional shutdown
circuitry as shown in the Typical Operating Circuit. This
shutdown transistor prevents a single-point fault at the
laser from creating an unsafe condition.
xK
APCFILT1
I
BIAS
CC
C
or GND. See Table 2 to view the circuit
APC
CC
I
APCFILT2
MOD
. The laser driver offers redundant
X1/2
V
Ratio Control
CC
V
I
X1
BG
APCSET
OUT-
OUT+
BIAS
APCSET
MD
SHUTDOWN
Safety Circuitry
R
APCSET
R
D
I
I
BIAS
MD
C
V
MD
CC
CC
as
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