MAX14950 Datasheet, PDF (16/17 Pages) Maxim Integrated Products – Quad PCI Express Equalizer/Redriver

MAX14950
Quad PCI Express Equalizer/Redriver
MAIN BOARD
Tx
PCIe
Rx
MAX14950
MAX14950
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 MAX14950s,
both residing on the main board, with input and output
equalization set individually for optimal performance.
The MAX14950 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
section 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 VCC. Always connect VCC
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 IC. 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
packages, 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 rat-
ings because stresses beyond the listed ratings may
cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all devices. Always apply GND then VCC before apply-
ing signals, especially if the signal is not current limited.
PROCESS: BiCMOS
Chip Information
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
42 TQFN-EP
PACKAGE
CODE
T423590+1
OUTLINE
NO.
21-0181
LAND
PATTERN NO.
90-0078
16  
Maxim Integrated