MAX3766E/D Maxim Integrated, MAX3766E/D Datasheet - Page 8

• Manufacturer Part Number: MAX3766E/D
• Description: Laser Drivers
• Manufacturer: Maxim Integrated
• Type: Laser Driverr

Specifications of MAX3766E/D

• Data Rate: 155 Mbps to 622 Mbps
• Operating Supply Voltage: 5 V
• Supply Current: 25 mA
• Maximum Operating Temperature: + 85 C
• Package / Case: Dice
• Maximum Power Dissipation: 590 mW
• Minimum Operating Temperature: - 40 C

The available laser bias current is programmed by
connecting external resistor R
BIASMAX. The BIASMAX programming current is
adjusted by the APC circuit and amplified by the laser
bias circuit.
An internal 520Ω resistor between BIASMAX and the
mirror input at internal node APC limits the maximum
laser bias current when BIASMAX is connected directly
to REF1. BIASMAX can be directly connected to REF1
in space-constrained designs, causing the maximum
622Mbps LAN/WAN Laser Driver with
Automatic Power Control and Safety Shutdown
Figure 2. Functional Diagram
8
SAFETY
ENABLE
V
V
IN+
IN-
_______________________________________________________________________________________
CC
CC
V
CC
5.1k
PECL
INPUT
BUFFER
START-UP
SHDN
SAFETY
CIRCUIT
FAIL
520Ω
MOD
MODULATION
MIRROR
30X
R
MOD
GNDOUT
REF2
REFERENCE
GENERATOR
FAILURE
BIASMAX
SHDN
MODULATION-
CURRENT
DRIVER
MAX3766
VCCOUT
TC
from REF1 to
2k
V
R
TC
TEMP
DETECTION
REF1
FAILURE
programming current (about 2.5mA) to flow into
BIASMAX. Selecting a BIASMAX resistor saves power
and limits the transmitter’s maximum light output.
R
This equation applies to maximum bias currents above
10mA.
BIASMAX
V
BANDGAP
R
TEMP
BIASMAX
LASER BIAS CIRCUIT
APC
can be estimated as follows:
R
R
BIASMAX
POWERSET
BIASMAX
520Ω
MONITOR-
DIODE
AMPLIFIER
POWERSET
MIRROR
1X
I
APC
BIAS
MIRROR
40X
=
POWERSET
AUTOMATIC
POWER CONTROL
I
1.55V 40
300Ω
BIASMAX
( )
V
CC
- 2V
−
520
MD
BIAS
OUT+
OUT-
MONITOR
PHOTODIODE
Ω
C
MD
LASER
V
V
V
CC
CC
CC