KSZ8721BL Micrel Inc, KSZ8721BL Datasheet - Page 15

• Manufacturer Part Number: KSZ8721BL
• Description: IC TXRX PHY 10/100 3.3V 48-LQFP
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of KSZ8721BL

• Number Of Drivers/receivers: 1/1
• Protocol: MII, RMII
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Data Rate: 100Mbps
• No. Of Ports: 1
• Ethernet Type: IEEE 802.3u
• Supply Current: 151mA
• Supply Voltage Range: 3.3V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 48
• Interface Type: MII, RMII
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1627 - BOARD EVALUATION FOR KSZ8721BMC576-1626 - BOARD EVALUATION FOR KSZ8721BL
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-1028-5; 576-1511-5; 576-1511-5; KSZ8721BL

Micrel, Inc.
RMII AC Characteristics
Unused RMII Pins
Input Pins
Output Pins
Auto-Crossover (Auto-MDI/MDI-X)
Automatic MDI/MDI-X configuration is intended to eliminate the need for crossover cables between similar devices. The
assignment of pinouts for a 10/100 BASE-T crossover function cable is shown below.
This feature eliminates the confusion in applications by allowing the use of both straight and crossover cables. This
feature is controlled by register 1f:13. See “Register 1fh–100BASE-TX PHY Controller” section for details.
June 2009
Symbol
t
t
SU
H
Parameter
REF_CLK Frequency
REF_CLK Duty Cycle
TXD[1:0], TX_EN, RXD[1:0], CRS_DV, RXER
TXD[1:0], TX_EN, RXD[1:0], CRS_DV, RXER
Data Hold from REF_CLK
Rising Edge
TXD[2:3] and TXER are pull-down to GND.
RXD[2:3] and RXC are no connect.
Note that the RMII pin needs to be pulled up to enable RMII mode.
10/100 BASE-T
Media Dependent Interface
Modular Connector (RJ45)
Transmit Pair
Receive Pair
NIC
Figure 1. Straight Through Cable
15
10/100 BASE-T
Media Dependent Interface
Modular Connector (RJ45)
(Repeater or Switch)
Receive Pair
Transmit Pair
HUB
Min
35
4
2
Typ
50
Max
M9999-062509-1.3
65
KS8721BL/SL
Units
MHz
ns
ns
%