Specifications
Gigabit Multimedia Serial Link Deserializer
with LVDS System Interface
MAX9268
______________________________________________________________________________________ 29
Board Layout
Separate the digital signals and CML/LVDS high-speed
signals to prevent crosstalk. Use a four-layer PCB with
separate layers for power, ground, CML/LVDS, and digital
signals. Layout PCB traces close to each other for a 100I
differential characteristic impedance. The trace dimensions
depend on the type of trace used (microstrip or stripline).
Note that two 50I PCB traces do not have 100I differen-
tial impedance when brought close together because the
impedance goes down when the traces are brought closer.
Route the PCB traces for a CML/LVDS channel (there
are two conductors per CML/LVDS channel) in parallel to
maintain the differential characteristic impedance. Avoid
vias. Keep PCB traces that make up a differential pair equal
length to avoid skew within the differential pair.
ESD Protection
The MAX9268 ESD tolerance is rated for Human Body
Model, IEC 61000-4-2, and ISO 10605. The ISO 10605
and IEC 61000-4-2 standards specify ESD tolerance for
electronic systems. CML/LVDS I/O are tested for ISO 10605
ESD protection and IEC 61000-4-2 ESD protection. All
pins are tested for the Human Body Model. The Human
Body Model discharge components are C
S
= 100pF and
R
D
= 1.5kI (Figure 24). The IEC 61000-4-2 discharge
components are C
S
= 150pF and R
D
= 330I (Figure 25).
The ISO 10605 discharge components are C
S
= 330pF and
R
D
= 2kI (Figure 26).
Table 11. Suggested Connectors and
Cables for GMSL
Figure 24. Human Body Model ESD Test Circuit
Figure 26. ISO 10605 Contact Discharge ESD Test Circuit
Figure 25. IEC 61000-4-2 Contact Discharge ESD Test Circuit
VENDOR CONNECTOR CABLE
JAE Electronics, Inc. MX38-FF A-BW-Lxxxxx
Nissei Electric Co., Ltd. GT11L-2S
F-2WME
AWG28
Rosenberger
Hochfrequenztechnik GmbH
D4S10A-40ML5-Z Dacar 538
STORAGE
CAPACITOR
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
1MI
R
D
1.5kI
C
S
100pF
STORAGE
CAPACITOR
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
R
D
2kI
C
S
330pF
C
S
150pF
STORAGE
CAPACITOR
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
R
D
330I