MAX3737ETJ+T Maxim Integrated Products, MAX3737ETJ+T Datasheet - Page 10

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

Specifications of MAX3737ETJ+T

• 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

The MAX3737 features monitors (MC_MON, BC_MON,
PC_MON) for modulation current (I
(I
Multirate Laser Driver with Extinction
Ratio Control
Table 1. Typical Fault Conditions
*A fault state asserts the TX_FAULT pin, disables the modulation and bias currents, and asserts the SHUTDOWN pin.
10
Table 2. Circuit Responses to Various Single-Point Faults
BIAS
TX_DISABLE
SHUTDOWN
1
2
3
4
TX_FAULT
MC_MON
APCFILT1
APCFILT2
PC_MON
BC_MON
MODSET
APCSET
OUT+
______________________________________________________________________________________
OUT-
BIAS
), and photocurrent (I
PIN
IN+
MD
IN-
If any of the I/O pins is shorted to GND or V
exceed the programmed threshold.
End-of-life (EOL) condition of the laser diode. The bias current and/or the photocurrent exceed the programmed threshold.
Laser cathode is grounded and photocurrent exceeds the programming threshold.
No feedback for the APC loop (broken interconnection, defective monitor photodiode), and the bias current exceeds the
programmed threshold.
Does not affect laser power.
Modulation and bias currents are disabled.
The optical average power increases and a fault occurs
if V
responds by decreasing the bias current.
The optical average power decreases and the APC loop
responds by increasing the bias current. A fault state
occurs if V
This disables bias current. A fault state occurs.
Does not affect laser power. If the shutdown circuitry is
used, laser current is disabled.
In this condition, laser forward voltage is 0V and no light
is emitted.
The APC circuit responds by increasing the bias current
until a fault is detected, then a fault state* occurs.
Does not affect laser power.
Fault state* occurs.
Fault state* occurs.
Fault state* occurs.
I
voltage.
I
voltage.
Does not affect laser power.
Does not affect laser power.
BIAS
BIAS
PC_MON
increases until V
increases until V
Safety Circuitry Current Monitors
CIRCUIT RESPONSE TO OVERVOLTAGE
BC_MON
exceeds the threshold. The APC loop
MD
). The monitors are realized
OR SHORT TO V
exceeds the threshold voltage.
BC_MON
BC_MON
MOD
), bias current
exceeds the threshold
exceeds the threshold
CC
CC
(single-point failure; see Table 2), and the bias current or the photocurrent
by mirroring a fraction of the currents and developing volt-
ages across external resistors connected to ground.
Voltages greater than V
BC_MON result in a fault state. For example, connecting a
Does not effect laser power.
Normal condition for circuit operation.
The optical average power decreases and the APC loop
responds by increasing the bias current. A fault state
occurs if V
The optical average power increases and a fault occurs
if V
responds by decreasing the bias current.
The APC circuit responds by increasing bias current
until a fault is detected, then a fault* state occurs.
Does not affect laser power.
Fault state* occurs. If the shutdown circuitry is used,
laser current is disabled.
Fault state* occurs. If the shutdown circuitry is used,
laser current is disabled.
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
I
voltage.
I
voltage.
Fault state* occurs.
Fault state* occurs.
BIAS
BIAS
PC_MON
increases until V
increases until V
CIRCUIT RESPONSE TO UNDERVOLTAGE
BC_MON
exceeds the threshold. The APC loop
OR SHORT TO GROUND
exceeds the threshold voltage.
REF
BC_MON
BC_MON
at MC_MON, PC_MON, or
exceeds the threshold
exceeds the threshold