CBTU0808
Dual lane PCI Express port multiplexer
Rev. 01 — 2 June 2006
Product data sheet
1. General description
The CBTU0808 is a dual lane port multiplexer designed to provide convenient and reliable
path switching for PCI Express signals. It is organized as two PCI Express lanes, each
consisting of a Transmit and Receive channel. Each channel has four ports, two (A and B)
on the source (or host) side and two (A and B) on the destination (or device) side. Each
port provides a pair of signal lines to support PCIe differential signaling.
Using specially designed high-bandwidth and high off-isolation switch elements, source
and destination ports can be connected or isolated in three possible configurations:
source A and B to destinations A and B respectively; or source A to destination B
(remaining ports isolated), or all ports isolated.
The switch elements are controlled by internal control logic to set switch positions in
accordance with these three configurations, selectable by CMOS inputs CTRL0 and
CTRL1 for lanes 0 and 1 respectively. Within a lane, the switch configuration is always
applied identically to both transmit and receive channels.
The CBTU0808 is packaged in a 48-ball, depopulated 9 × 9 grid, 0.5 mm ball pitch, thin
profile fine-pitch ball grid array (TFBGA) package, which (while requiring a minimum
5 mm × 5 mm of board space) allows for adequate signal routing and escape using
conventional board technology.
2. Features
I 2-lane wide PCI Express port multiplexer
I One transmit and one receive differential channel per lane
I Four ports per channel
I PCI Express signaling compliant
I High bandwidth: > 1 GHz
I Low OFF-feedthrough of < −35 dB at 1.25 GHz
I Low channel crosstalk of < −35 dB at 1.25 GHz
I Designed to match characteristic impedance of PCIe signaling environment
I Single 1.8 V supply operation
I ESD resilience of 2 kV HBM
I Available in 48-ball, 5 mm × 5 mm, 0.5 mm ball pitch TFBGA package, Pb-free/Green
3. Applications
I High-performance computing applications
I Port switching and docking applications