KSZ8081MNX Datasheet, PDF (1/69 Pages) Micrel Semiconductor – 10Base-T/100Base-TX Physical Layer Transceiver

KSZ8081MNX/KSZ8081RNB
10Base-T/100Base-TX
Physical Layer Transceiver
Revision 1.4
General Description
The KSZ8081 is a single-supply 10Base-T/100Base-TX
Ethernet physical-layer transceiver for transmission and
reception of data over standard CAT-5 unshielded twisted
pair (UTP) cable.
The KSZ8081 is a highly-integrated PHY solution. It
reduces board cost and simplifies board layout by using
on-chip termination resistors for the differential pairs and
by integrating a low-noise regulator to supply the 1.2V
core.
The KSZ8081MNX offers the Media Independent Interface
(MII) and the KSZ8081RNB offers the Reduced Media
Independent Interface (RMII) for direct connection with
MII/RMII-compliant Ethernet MAC processors and
switches.
A 25MHz crystal is used to generate all required clocks,
including the 50MHz RMII reference clock output for the
KSZ8081RNB.
The KSZ8081 provides diagnostic features to facilitate
system bring-up and debugging in production testing and
in product deployment. Parametric NAND tree support
enables fault detection between KSZ8081 I/Os and the
board. Micrel LinkMD^® TDR-based cable diagnostics
identify faulty copper cabling.
The KSZ8081MNX and KSZ8081RNB are available in 32-
pin, lead-free QFN packages (see “Ordering Information”).
Datasheets and support documentation are available on
website at: www.micrel.com.
Features
• Single-chip 10Base-T/100Base-TX IEEE 802.3
compliant Ethernet transceiver
• MII interface support (KSZ8081MNX)
• RMII v1.2 Interface support with a 50MHz reference
clock output to MAC, and an option to input a 50MHz
reference clock (KSZ8081RNB)
• Back-to-back mode support for a 100Mbps copper
repeater
• MDC/MDIO management interface for PHY register
configuration
• Programmable interrupt output
• LED outputs for link, activity, and speed status indication
• On-chip termination resistors for the differential pairs
• Baseline wander correction
• HP Auto MDI/MDI-X to reliably detect and correct
straight-through and crossover cable connections with
disable and enable option
• Auto-negotiation to automatically select the highest link-
up speed (10/100Mbps) and duplex (half/full)
• Power-down and power-saving modes
• LinkMD TDR-based cable diagnostics to identify faulty
copper cabling
• Parametric NAND Tree support for fault detection
between chip I/Os and the board
• HBM ESD rating (6kV)
Functional Diagram
LinkMD is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
August 19, 2015
Revision 1.4