KSZ8091MNX/KSZ8091RNB
Micrel Inc., is a leading global manufacturer
of IC solutions for the worldwide analog,
Ethernet and high bandwidth markets.
The Company’s products include
advanced mixed-signal, analog and
power semiconductors; high performance
communication, clock management, Ethernet
switch and physical layer transceiver
ICs. Company customers include leading
manufacturers of enterprise, consumer,
industrial, mobile, telecommunications,
automotive, and computer products.
Corporation headquarters and state-of-
the-art wafer fabrication facilities are located
in San Jose, CA with regional sales and
support ofces and advanced technology
design centers situated throughout the
Americas, Europe and Asia. In addition, the
Company maintains an extensive network of
distributors and reps worldwide.
www.micrel.com
Applications
• Game console
• IP phone
• IP set-top box
• IP TV
• LOM
• Printer
For more information, contact your local Micrel
sales representative, or visit Micrel at:
www.micrel.com
10Base-T/100Base-TX Physical Layer Transceiver
Description
The KSZ8091 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 KSZ8091 is a highly-integrated PHY solution. It
reduces board cost and simplies board layout by using
on-chip termination resistors for the differential pairs, by
integrating a low-noise regulator to supply the 1.2V core,
and by offering a exible 1.8/2.5/3.3V digital I/O interface.
The KSZ8091MNX offers the Media Independent Interface
(MII) and the KSZ8091RNB offers the Reduced Media
Independent Interface (RMII) for direct connection with MII/
RMII-compliant Ethernet MAC processors and switches.
Energy Efcient Ethernet (EEE) provides further power
saving during idle trafc periods and Wake-on-LAN (WOL)
provides a mechanism for the KSZ8091 to wake up a
system that is in standby power mode.
The KSZ8091 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 KSZ8091 I/Os and the
board. Micrel LinkMD® TDR-based cable diagnostics
identify faulty copper cabling.
The KSZ8091MNX and KSZ8091RNB are available in 32-
pin, lead-free QFN packages.
Functional Diagram
KSZ8091MNX/
KSZ8091RNB
MAGNETICS
RJ-45
CONNECTOR
MEDIA TYPES:
10BASE-T
100BASE-TX
ON-CHIP TERMINATION
RESISTORS
MII/RMII
MDC/ MDIO
MANAGEMENT
XO XI
25MHz
XTAL
22pF
22pF
10/100Mbps
MII/RMII MAC
50MHz
(KSZ8091RNB)
REF_CLK
PME_N
(SYSTEM
POWER
CIRCUIT)
KSZ8091MNX/KSZ8091RNB - 10Base-T/100Base-TX PHYSICAL LAYER TRANSCEIVER
1.800.944.0800 Tel
1.408.474.1000 Fax
www.micrel.com
09/03/2013
© 2013 Micrel, Inc. All rights reserved. Micrel and LinkMD are registered trademarks of Micrel, Inc.
Contact Micrel, Inc.
Corporate HQ 2180 Fortune Drive San Jose, CA 95131 USA +1 408 944 0800 +1 408 944 0970
Western USA 2180 Fortune Drive San Jose, CA 95131 USA +1 408 944 0800 +1 408 944 0970
Central USA 2425 N. Central Express Way, Suite 351 Richardson, TX 75080 USA +1 972 393 2533 +1 972 393 2370
Eastern USA 93 Branch Street Medford, NJ 08055 USA +1 609 654 0078 +1 609 654 0989
Latin America 2425 N. Central Express Way, Suite 351 Richardson, TX 75080 USA +1 972 393 2533 +1 972 393 2370
Hong Kong Unit 213-215, Photonics Centre, #2 Science Park East Ave., Hong Kong Science Park Shatin, N.T., Hong Kong +852 2886 8839 +852 2886 8851
China No. 2001 & 2002, 20/F, Excellence Times Plaza, 4068 Yitian Road, Futian Dist Shenzhen, P.R. China 518048 +86 755 8302 7618 +86 755 8302 7637
Japan 2-3-1 Minato Morai Queen’s Tower A 14F, Nishi-ku, Yokohama Kanagawa 220-6014, Japan +81 45 224 6616 +81 45 224 6716
Korea 42nd Flr, Korean Academy of Science and Tech Bldg, 7-1 Gumi-dong Bundang-gu Gyeonggi, 463-808, Korea +82 2 538 2380 +82 2 538 2381
Singapore/India 7500A Beach Road, #07-324 The Plaza Singapore 199591 +65 6291 1318 +65 6291 1332
Taiwan 4F, No. 43 Lane 188, Rueiguang Road, Nei-Hu District Taipei 11491 Taiwan, R.O.C +886 2 8751 0600 +886 2 8751 0746
UK/EMEA 1st Floor, 3 Lockside Place, Mill Lane, Newbury, Berks United Kingdom RG14 5QS +44 1635 524455 +44 1635 524466
France/Southern Europe Les Laurentides - Batiment Ontario, 3 Avenue du Quebec 91140 Villebon sur Yvette, France +33 0 1 6092 4190 +33 0 1 6092 4189
Location Address Telephone Fax
Key Features Benets
Single-chip 10Base-T/100Base-TX IEEE 802.3-compliant Ethernet
transceiver
Standard compliance ensures that the device will work with other standard-
compliant, already deployed devices
MII interface (KSZ8081MNX) and RMII v1.2 Interface support with a 50MHz
reference clock output to MAC, and an option to input a 50MHz reference
clock (KSZ8081RNB)
Provides exible options for the 50MHz RMII reference clock as the input
or output
Back-to-back mode support Allows creation of low-cost 100Mbps copper repeater using only two
KSZ8091 PHYs
MDC/MDIO management interface for PHY register conguration Allows the MAC processor complete access to the KSZ8091 control and
status registers
On-chip termination resistors for the differential pairs
On-chip termination (eliminating four external resistors) simplies PCB
design, reduces system BOM, and improves overall signal integrity and
EMI emission
On-chip regulator Reduces BOM cost by eliminating external regulator for 1.2V core
HP Auto MDI/MDI-X to reliably detect and correct straight-through and
crossover cable connections with disable and enable option
Easy-to-use feature eliminates the need for crossover cable, which reduces
installation costs
Energy Efcient Ethernet (EEE) support with low-power idle (LPI) mode and
clock stoppage (MII version only) for 100Base TX and transmit amplitude
reduction with 10Base-Te option
Saves greater than 50% power in idle mode
Wake-on-LAN (WOL) support with either magic packet, link status change,
or robust custom-packet detection
Provides a mechanism to wake up a system that is in standby power mode,
saving total system power consumption
Multiple loopback options Allows diagnostic testing for RMII and line side data paths
Single 3.3V power supply with VDD I/O options for 1.8V, 2.5V, or 3.3V Enables low-power and exible I/O design
Power-down and power-saving modes Optimizes power consumption based on the status of the link or the device
LinkMD TDR-based cable diagnostics Identies common cable faults in production testing and in deployment
