MAX14954 Datasheet, PDF (16/17 Pages) Maxim Integrated Products – Computer on Modules

MAX14954
Ruggedized Quad PCIe Redriver with
Equalization and Extended Temperature Operation
MAIN BOARD
Tx
PCIe
Rx
MAX14954
MAX14954
MIDPLANE
4 DIFFERENTIAL PAIRS
4 DIFFERENTIAL PAIRS
REMOTE BOARD
Rx
PCIe
Tx
CONNECTORS
Figure 2. Typical Application Diagram
Applications Information
Figure 2 shows a typical application with two MAX14954s,
both residing on the main board with input and output
equalization set individually for optimal performance. The
MAX14954 Rx equalizer is set to receive a degraded
signal coming from a remote board through two sets of
connectors and a midplane stripline. The output of the Rx
section has little or no output equalization. The Tx sec-
tion takes a high-quality signal and provides boost to the
output (deemphasis).
Layout
Circuit-board layout and design can significantly affect
the performance of the device. Use good, high-frequency
design techniques, including minimizing ground induc-
tance and using controlled-impedance transmission lines
on data signals. Power-supply decoupling should also be
placed as close as possible to V_CC. Always connect V_CC
to a power plane. It is recommended to run receive and
transmit signals on different layers to minimize crosstalk.
Exposed-Pad Package
The exposed-pad, 42-pin TQFN package incorporates
features that provide a very low-thermal-resistance path
for heat removal from the device. The exposed pad on
the device must be soldered to the circuit-board ground
plane for proper thermal performance and good ground
connectivity. For more information on exposed-pad pack-
ages, refer to Application Note 862: HFAN-08.1: Thermal
Considerations of QFN and Other Exposed-Paddle
Packages.
Power-Supply Sequencing
Caution: Do not exceed the absolute maximum ratings
because stresses beyond the listed ratings can cause
permanent damage to the device.
Proper power-supply sequencing is recommended for all
devices. Always apply GND then VCC before applying
signals, especially if the signal is not current limited.
Ordering Information
PART
MAX14954ETO+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
42 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
42 TQFN-EP T423590+1
OUTLINE
NO.
21-0181
LAND
PATTERN
NO.
90-0078
www.maximintegrated.com
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