LAN8720A-CP-TR Standard Microsystems (SMSC), LAN8720A-CP-TR Datasheet - Page 5

• Manufacturer Part Number: LAN8720A-CP-TR
• Description: SMALL FOOTPRINT RMII 10/100 ETHERNET TR
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LAN8720A-CP-TR

• Number Of Receivers: 1
• Protocols Supported: IEEE 802.3
• Operating Supply Voltage (typ): 1.8/2.5/3.3V
• Package Type: QFN
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Operating Temperature (max): 85C
• Operating Temperature (min): 0C
• Lead Free Status / Rohs Status: Compliant

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
List of Figures
Figure 1.1 System Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 1.2 Architectural Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 2.1 24-QFN Pin Assignments (TOP VIEW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 3.1 Relationship Between Received Data and Specific MII Signals . . . . . . . . . . . . . . . . . . . . . . 21
Figure 3.2 Direct Cable Connection vs. Cross-over Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 3.3 MDIO Timing and Frame Structure - READ Cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 3.4 MDIO Timing and Frame Structure - WRITE Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 3.5 External 50MHz clock sources the REF_CLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 3.6 Sourcing REF_CLK from a 25MHz Crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 3.7 Sourcing REF_CLK from External 25MHz Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 3.8 LED1/REGOFF Polarity Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 3.9 LED2/nINTSEL Polarity Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 3.10 Near-end Loopback Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 3.11 Simplified System Level Application Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 3.12 Power Supply Diagram (1.2V Supplied by Internal Regulator) . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 3.13 Power Supply Diagram (1.2V Supplied by External Source) . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 3.14 Twisted-Pair Interface Diagram (Single Power Supply) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 3.15 Twisted-Pair Interface Diagram (Dual Power Supplies). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Figure 5.1 Output Equivalent Test Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Figure 5.2 Power Sequence Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Figure 5.3 Power-On nRST & Configuration Strap Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Figure 5.4 RMII Timing (REF_CLK Out Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figure 5.5 RMII Timing (REF_CLK In Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Figure 5.6 SMI Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
SMSC LAN8720/LAN8720i
5
Revision 1.0 (12-09-09)
DATASHEET