MAX3996CGP Maxim Integrated Products, MAX3996CGP Datasheet - Page 9

• Manufacturer Part Number: MAX3996CGP
• Description: Laser Driver +3.0V to +5.5V, 2.5G bps VCSEL and Laser
• Manufacturer: Maxim Integrated Products

Specifications of MAX3996CGP

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 2. R
Table 3. Circuit Responses to Various Single-Point Faults
*A fault state asserts the FAULT pin, disables the modulator outputs, disables the bias output, and asserts the SHDNDRV pin.
IC pins. See Table 3 to view the circuit response to vari-
ous single-point failures. The shutdown condition is
latched until reset by a toggle of TX_DISABLE or V
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
TX_DISABLE
OUT+, OUT-
PIN NAME
SHDNDRV
TEMPCO
MODSET
(ppm/°C)
PORDLY
IN+, IN-
FAULT
MON1
MON2
COMP
BIAS
3500
3000
2500
2000
1500
1000
500
MD
TC
TC
Does not affect laser power.
Does not affect laser power.
Modulation and bias current are disabled.
Does not affect laser power.
Does not affect laser power.
Fault state* occurs.
Fault state* occurs.
A fault is detected at either the collector or the emitter
of the internal bias transistor, and a fault state* occurs.
If the shutdown circuitry is used, bias current is shut off.
Disables bias current.
Does not affect laser power. If the shutdown circuitry is
used, bias current is shut off.
In this condition, laser forward voltage is 0V and no
light is emitted.
Does not affect laser power.
Does not affect laser power. Fault* state may occur.
and R
_______________________________________________________________________________________
R
CIRCUIT RESPONSE TO OVERVOLTAGE OR
MOD
17.1
8.04
5.20
3.81
2.98
2.44
2.05
MOD
(kΩ)
i
MOD
Selection Table
= 30mA
SHORT TO V
Fault Detection
R
TC
1.85
2.19
2.68
3.42
4.64
7.08
14.4
(kΩ)
CC
3.0V to 5.5V, 2.5Gbps VCSEL
CC.
R
MOD
34.4
16.3
10.6
7.86
6.21
5.12
4.34
(kΩ)
i
Applications Information for more information on laser
safety.
The laser driver offers redundant bias shutdown. The
SHDNDRV output drives an optional external transistor.
The bias and modulation drivers have separate internal
disable signals.
MOD
= 15mA
Fault state* occurs.
Does not affect laser power.
Normal condition for circuit operation.
Modulation and bias current are disabled.
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
Disables bias current.
The APC circuit responds by increasing bias current
until a fault is detected at the emitter or collector of the
bias transistor, and then a fault* state occurs.
Does not affect laser power.
Fault state* occurs. If the shutdown circuitry is used,
bias current is shut off.
Does not affect laser power.
Fault state* occurs.
CIRCUIT RESPONSE TO UNDERVOLTAGE OR
R
TC
3.94
4.64
5.62
7.08
9.53
14.4
29.1
(kΩ)
and Laser Driver
SHORT TO GROUND
R
MOD
49.5
32.4
24.1
19.1
15.9
13.5
104
(kΩ)
i
MOD
= 5mA
Shutdown
R
TC
12.3
14.4
17.4
21.8
29.1
43.8
87.8
(kΩ)
9