Datasheet

MAX3766
622Mbps LAN/WAN Laser Driver with
Automatic Power Control and Safety Shutdown
6 _______________________________________________________________________________________
Pin Description
ENABLE is a TTL-compatible input. When low or open, this pin disables the output modulation and bias
current.
ENABLE10
A capacitor to ground at SAFETY determines the turn-on delay for the safety circuits. If SAFETY is
grounded or TTL low, internal safety shutdown features are disabled. A TTL high at SAFETY enables the
internal safety shutdown features.
SAFETY11
The FAIL output asserts low if the voltage at MD is above or below nominal. FAIL also asserts if REF1 is
inadvertently tied to the positive supply. FAIL has TTL-compatible output voltage levels.
FAIL
12
Supply Voltage for the Output Current DriversV
CCOUT
13
Inverting Modulation-Current OutputOUT-14
Ground. All grounds must be connected.GND5, 8
Inverting Data InputIN-6
Noninverting Data InputIN+7
Positive Supply Voltage. All V
CC
pins must be connected.V
CC
9
The current into MOD programs the laser modulation current. Connect MOD to REF2 with a resistor or
potentiometer.
MOD4
REF2 is the reference voltage used to program the modulation current. The tempco of REF2 is pro-
grammed by R
TC
.
REF23
PIN
The resistance (R
TC
) between TC and REF1 programs the temperature coefficient of REF2. Connecting
TC directly to REF1 produces the minimum tempco. Leaving TC unconnected produces the maximum
tempco.
TC2
The current into BIASMAX sets the maximum laser bias current. Connecting BIASMAX directly to REF1
allows the largest possible bias current.
BIASMAX1
FUNCTIONNAME
Ground for the Output Current DriversGNDOUT17
Input for the laser monitor photodiode current. MD18
The current into POWERSET programs the average optical output power when automatic power
control is used.
POWERSET19
REF1 is a voltage reference used to program laser bias current and average power.REF120
Noninverting Modulation-Current OutputOUT+15
Connection for the DC Laser Bias CurrentBIAS16