MAX4888C Maxim, MAX4888C Datasheet - Page 9

• Manufacturer Part Number: MAX4888C
• Description: The MAX4888B/MAX4888C dual double-pole/double-throw (2 x DPDT), high-speed passive switches are ideal for switching two half-lanes of PCI Express® (PCIe) data between two possible destinations
• Manufacturer: Maxim

The MAX4888B high-speed passive switch routes high-
speed differential signals such as PCIe, SAS, SATA,
and XAUI from one source to two possible destina-
tions or vice versa. The MAX4888B is ideal for routing
PCIe signals to change the system configuration. The
MAX4888C features a 10FA (typ) source current and
a 60kI (typ) internal biasing resistor to GND at the
AOUTA_, BOUTA_, AOUTB_, and BOUTB_ terminals.
The MAX4888C is ideal for circuits that are capacitively
coupled at both the output and input. These devices are
protocol independent and can be used to switch two dif-
ferent protocol signals over the same physical lane. They
feature dual digital control inputs (SEL, SELB) to switch
signal paths. SEL has a 70kI (typ) pulldown resistor to
GND and SELB has a 70kI (typ) pullup resistor to V
These devices are fully specified to operate from a single
3.0V to 3.6V power supply.
The devices provide dual digital control inputs (SEL,
SELB) to select the signal path between the AIN_, BIN_
and AOUTA_, BOUTA_ or AOUTB_, BOUTB_ chan-
nels. In most cases SEL is chosen and SELB is uncon-
nected. The truth table for the devices is depicted in the
Functional Diagram/Truth Table. SEL has a 70kI (typ)
pulldown resistor to GND and SELB has a 70kI (typ)
pullup resistor to V
The devices accept signals from -0.3V to (V
Signals on the AIN+ and BIN+ channels are routed to
either the AOUTA+, BOUTA+ or AOUTB+, BOUTB+
channels. Signals on the AIN- and BIN- channels are rout-
ed to either the AOUTA-, BOUTA- or AOUTB-, BOUTB-
channels. The devices are bidirectional switches, allow-
ing AIN_, BIN_ and AOUTA_, BOUTA_, AOUTB_, and
BOUTB_ to be used as either inputs or outputs.
Digital Control Input (SEL, SELB)
CC
.
Detailed Description
Up to 8.0Gbps Dual Passive Switches
Analog-Signal Levels
CC
- 1.8V).
CC
.
The devices’ primary applications are aimed at sharing
resources. For example, a single lane of PCIe or SAS
can be shared between a single host and two devices.
This could be used for redundancy or to share resources
such as a physical lane or route a lane between one host
and two devices or two hosts and one device.
High-speed switches require proper layout and design
procedures for optimum performance. Keep controlled
impedance PCB traces as short as possible or follow
impedance layouts per the PCIe specification. Ensure
that power-supply bypass capacitors are placed as
close as possible to the device. Multiple bypass capaci-
tors are recommended. Connect all grounds and the
exposed pad to a large ground plane.
PROCESS: CMOS
For the latest package outline information and land patterns,
go to www.maxim-ic.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.
28 TQFN-EP
PACKAGE
TYPE
Applications Information
T283555+1
PACKAGE
CODE
Package Information
High-Speed Switching
Chip Information
OUTLINE
21-0184
NO.
Board Layout
PATTERN NO.
90-0123
LAND
9