Layout considerations, Laser safety and iec 825 – Rainbow Electronics MAX3737 User Manual
Page 13
Layout Considerations
To minimize loss and crosstalk, keep the connections
between the MAX3737 output and the laser diode as
short as possible. Use good high-frequency layout
techniques and multilayer boards with uninterrupted
ground plane to minimize EMI and crosstalk. Circuit
boards should be made using low-loss dielectrics. Use
controlled-impedance lines for data inputs, as well as
the module output.
Laser Safety and IEC 825
Using the MAX3737 laser driver alone does not ensure
that a transmitter design is IEC 825 compliant. The entire
transmitter circuit and component selections must be
considered. Each customer must determine the level of
fault tolerance required by their application, recognizing
that Maxim products are not designed or authorized for
use as components in systems intended for surgical
implant into the body, for applications intended to support
or sustain life, or for any other application where the fail-
ure of a Maxim product could create a situation where
personal injury or death may occur.
MAX3737
Multirate Laser Driver with Extinction
Ratio Control
______________________________________________________________________________________
13
PC_MON
BC_MON
MC_MON
R
PC_MON
R
BC_MON
R
MC_MON
V
CC
V
CC
MAX3737
COMP
R
Q
S
RS
LATCH
CMOS
SHUTDOWN
TX_FAULT
TX_DISABLE
TTL
OPEN
COLLECTOR
COMP
COMP
EXCESSIVE
MODULATION
CURRENT
V
CC
I
MD
1
V
CC
V
REF
V
REF
V
REF
I
BIAS
82
I
MOD
268
I
MOD
ENABLE
I
BIAS
ENABLE
COUNTER
60ms DELAY
100ns
DELAY
POR AND COUNTER
60ms DELAY
Figure 5. Simplified Safety Circuit
MAX3737
5k
Ω
16k
Ω
5k
Ω
24k
Ω
PACKAGE
V
CC
V
CC
0.83nH
0.83nH
0.11pF
0.11pF
V
CC
Figure 6. Simplified Input Structure