MAX3296CTI+T Maxim Integrated Products, MAX3296CTI+T Datasheet - Page 11

• Manufacturer Part Number: MAX3296CTI+T
• Description: IC LASR DRVR 2.5GBPS 5.5V 28TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driver (Fiber Optic)r

Specifications of MAX3296CTI+T

• Data Rate: 2.5Gbps
• Number Of Channels: 1
• Voltage - Supply: 3 V ~ 5.5 V
• Current - Supply: 52mA
• Current - Modulation: 30mA
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-WFQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

force a shutdown if a fault is detected. The shutdown
condition is latched until reset by a toggle of EN, EN, or
power.
Another safety system, open fiber control (OFC), uses
safety interlocks to prevent eye hazards. To accommo-
date the OFC standard, the MAX3286/MAX3296 series
provide dual enable inputs and dual fault outputs.
The safety circuitry contains fault detection, dual enable
inputs, latched fault outputs, and a pulse generator
(Figure 6).
Safety circuitry monitors the APC circuit to detect unsafe
levels of laser emission during single-point failures. A
single-point failure can be a short to V
short between any two IC pins.
Figure 5. Modulation Current vs. Temperature for Maximum
and Minimum Temperature Coefficient
Figure 6. Simplified Safety Circuit Schematic
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0
10
R
R
TEMPCO = 4000ppm/ C
TC
MOD
20 30 40
______________________________________________________________________________________
JUNCTION TEMPERATURE ( C)
EN
EN
= OPEN
1.9k
V
CC
R
TEMPCO = 50ppm/ C
50 60 70 80 90 100 110
TC
= OPEN
(FROM POR CIRCUIT)
POLARITY_FAULT
MONITOR_FAULT
CC
3.0V to 5.5V, 1.25Gbps/2.5Gbps
MOD_FAULT
REF_FAULT
MD_FAULT
TC_FAULT
or GND or a
DETECTION
FAULT
ENABLE
PULSE GENERATOR
During startup, the laser does not emit light and the
APC loop is not closed, triggering a fault signal. To
allow startup, an internal fault-delay pulse disables the
safety system for a programmable period of time, allowing
the driver to begin operation. The length of the pulse is
determined by the capacitor connected at FLTDLY and
should be set 5 to 10 times longer than the APC time
constant. The internal safety features can be disabled
by connecting FLTDLY to GND. Note that EN must be
high, EN must be low, and V
tional range for laser operation.
The MAX3286/MAX3296 series has extensive and com-
prehensive fault-detection features. All critical nodes
are monitored for safety faults, and any node voltage
that differs significantly from its expected value results
in a fault (Table 1). When a fault condition is detected,
the laser is shut down. See the Applications Information
section for more information on laser safety.
The laser drivers offer dual redundant bias shutdown
mechanisms. The SHDNDRV output drives an optional
external MOSFET semiconductor. The bias and modu-
lation drivers have separate internal disable signals.
Two complementary FAULT outputs are provided with
the MAX3286/MAX3296 series. In the event of a fault,
these outputs latch until one of three events occurs:
1) The power is switched off, then on.
t
FLTDLY
LAN Laser Drivers
R
DOMINANT
S
MAX3286
MAX3296
FAULT
LATCH
RESET
Q
CC
FLTDLY
FAULT
FAULT
SHDNDRV
Latched Fault Output
must be in the opera-
Pulse Generator
Fault Detection
Shutdown
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