1

PS8961D

12/10/12

Features

• 1:2 Gigabit LAN Switch

• Power-down support

• Low bit-to-bit skew: 200ps

• Very Low Crosstalk: –75dB @ 250MHz

• Status Indicator LEDs Switched with Ethernet pairs

• Enhanced ESD Protection (on A, B, C, LED pins):

– 1.0kV (machine model),

11kV (human body model)

• >650 MHz bandwidth

• Packaging:

– 56-contact TQFN (5 x 11mm, 0.5 pitch)

– 42-contact TQFN (3.5 x 9mm, 0.5 pitch)

– 42-contact TQFN (3.5 x 7mm, 0.4 pitch)

Description

The PI3L720 is a 8-Channel 2:1 multiplexer/demultiplexer LAN

Switch with Hi-Z outputs. Industry leading advantages include a

propagation delay of less than 250ps, resulting from its low channel

resistance and I/O capacitance. The device multiplexes differential

outputs from a Gigabit Ethernet transceiver (PHY) device to one

of two corresponding B or C outputs. The switch is bidirectional

and offers little or no attenuation of the high-speed signals at the

outputs. It is designed for low bit-to-bit skew, high channel-to-

channel noise isolation and is compatible with various standards,

such as 10/100/1000 Base-T (Ethernet).

The PI3L720 provides a Power Down input (PD), which can put

the device into standby mode (PD=1) while mobile, eliminating

an external power switch.

Generally, this part can be used to replace mechanical relays in

low-voltage LAN applications that interface a physical layer over

CAT 5 or CAT 6 unshielded twisted pair cable through an isolation

transformer.

Block Diagram

PI3L720

2:1 Mux/DeMux Gigabit Ethernet

LAN Switch with Power-down Mode

SEL

A3-

A3+

A0-

A0+

B0-

B0+

C0-

C0+

B3-

B3+

C3-

C3+

PD

POWER

DOWN

Truth Table

PD

SEL

Function

L

L

L

H

H

x

Hi-Z

Note:

1. IEC 6100-4-2

Applications

• Dual Physical Layer Device sharing to one interface

connector, or one controller to dual connectors for docking

• Routes signals for 10/100/1000 Mbit Ethernet