MAX3766 Maxim, MAX3766 Datasheet - Page 14

• Manufacturer Part Number: MAX3766
• Description: 622Mbps LAN/WAN Laser Driver with Automatic Power Control and Safety Shutdown
• Manufacturer: Maxim

622Mbps LAN/WAN Laser Driver with
Automatic Power Control and Safety Shutdown
Table 3. MAX3766 Fault Response in Latched Shutdown Configuration
14
REF2, TC, MOD
______________________________________________________________________________________
OUT+, BIAS
POWERSET
BIASMAX
ENABLE
SAFETY
IN+, IN-
REF1
OUT-
FAIL
PIN
MD
Depending upon the setting of R
there is either no effect, or a latched shutdown.
High voltage on REF1 causes a failure and latched
shutdown.
Modulation current is increased. Either the APC
circuit will reduce power levels, or an overcurrent
will be detected at MD, causing a failure signal
and latched shutdown.
Normal condition for circuit operation.
Forces output to either constant 1 or 0. APC main-
tains the power level at the programmed level.
Normal condition for circuit operation.
No effect on circuit.
Voltage increase at these pins will turn off the
laser.
Normal condition for circuit operation.
Voltage increase at MD causes a failure and output
current shutdown.
Laser output increases, but is limited by the setting
of R
CIRCUIT RESPONSE TO OVERVOLTAGE
BIASMAX
.
OR SHORT TO V
POWERSET
CC
,
Bias current reduction causes a low laser output,
resulting in a latched shutdown.
Modulation and bias currents are reduced or off;
no hazard exists.
Modulation current is reduced; no hazard exists.
Modulation and bias currents are shut down.
Forces output to either constant 1 or 0. APC main-
tains the power level at the programmed level.
Safety shutdown features are disabled, but a
hazard is not created.
No effect on circuit.
High laser output asserts FAIL. A complete short
will destroy the laser, eliminating the hazard. A
resistive short may cause a hazard. External
circuitry combined with the FAIL signal may be
used to protect against a resistive short (Figure 10).
Forces output to be logic 1. APC maintains the
power level at the programmed level.
Voltage decrease at MD causes a failure and
output current shutdown.
Laser output decreases.
CIRCUIT RESPONSE TO UNDERVOLTAGE
OR SHORT TO GROUND