MAX3850EGJ Maxim Integrated Products, MAX3850EGJ Datasheet - Page 12

• Manufacturer Part Number: MAX3850EGJ
• Description: Laser Driver
• Manufacturer: Maxim Integrated Products

For high-current density and reliable operation, the
MAX3850 uses gold metalization. Make connections to
the die with gold wire only, using ball-bonding tech-
niques. Wedge bonding is not recommended. Die-pad
size is 4mils (100µm) square, and die thickness is
12mils (300µm) square.
To minimize inductance, keep the connections between
the MAX3850 output pins and laser diode as close as
possible. Optimize the laser diode performance by
placing a bypass capacitor as close as possible to the
laser anode. Use good high-frequency layout tech-
niques and multilayer boards with uninterrupted ground
planes to minimize EMI and crosstalk.
Using the MAX3850 laser driver alone does not ensure
that a transmitter design is compliant with IEC825. The
entire transmitter circuit and component selections
must be considered. Each user must determine the
level of fault tolerance required by the application, rec-
ognizing that Maxim products are neither designed nor
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 in which the failure of a Maxim product
could create a situation where personal injury or death
may occur.
2.7Gbps, +3.3V DC-Coupled Laser Driver
Figure 5. Simplified Input Circuit
12
IN+
IN-
______________________________________________________________________________________
PACKAGE
0.9nH
0.9nH
0.1pF
0.1pF
V
V
CC
CC
Laser Safety and IEC825
5kΩ
5kΩ
Layout Considerations
24kΩ
5kΩ
Wirebonding Die
V
CC
Figure 6. Simplified Output Circuit
LATCH
TOP VIEW
DATA+
DATA-
CLK+
CLK-
V
V
V
THE EXPOSED PAD MUST BE SOLDERED TO GND ON THE CIRCUIT BOARD
CC1
CC1
CC1
1
2
3
4
5
6
7
8
32
9
31
10
5mm
30
11
MAX3850
29
12
V
CC
5mm QFN
Pin Configuration
28
13
27
14
26
15
PACKAGE
0.1pF
0.1pF
25
16
0.9nH
0.9nH
24 MD
23 GND3
22
21
20
19
18
17
GND4
V
OUT-
OUT+
V
BIAS
CC4
CC4
OUT+
OUT-