6 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
AX88180 Gigabit Ethernet Controller Application Design Note
4 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
AX88180 Gigabit Ethernet Controller Application Design Note
1. Introduction
ASIX Electronics provides some cost-effective and highly integrated embedded Ethernet controllers that support generic processor interface (local bus interface or Non-PCI) or SRAMlike interface that are commonly used in embedded system applications. The following URL provides detailed online resource of ASIX Electronics single port embedded Ethernet solutions: (Refer to /products.php?op=ProductList&PLine=65.) This Application Design Note applies specifically to the following Gigabit Ethernet controller, namely, AX88180. AX88180 -- High-Performance Non-PCI 32-bit 10/100/1000M Gigabit Ethernet Controller This Application Design Note provides important information about external component selection, schematic design and PCB design/layout for designing with ASIX Electronics’ embedded Gigabit Ethernet controller. ASIX Electronics highly recommends that user read through this Design Note before starting hardware design on schematic capture and PCB layout.
AX88180 Gigabit Ethernet Controller Application Design Note
Revision History
Revision 1.00 1.01 Date 2008/08/15 2008/09/09 Description Initial Release 1. Update the reference circuits in Section 2, 3, 4 and 10.
9. EMI Considerations............................................................................18 10. ESD Considerations.........................................................................20
The following is the EEPROM reference circuit of AX88180 Non-PCI 32-bit 10/100/1000M Gigabit Ethernet application.
Note: 1. The AX88180 supports 16-bit data access serial EEPROM device such as 93C56 EEPROM. The 93C56 EEPROM is optional if the MAC address can be stored on the Flash memory of your embedded system. The other EEPROM setting can also be configured by AX88180 registers setting.
8-1. Improve the Cooling ....................17 8-2. Improve the Air Convection............................................................................17 8-3. Disable the on-chip regulator ..........................................................................17
AX88180 Gigabit Ethernet Controller Application Design Note
AX88180 Gigabit Ethernet Controller Application Design Note
Revision 1.01 Sep. 9th, 2008
1 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
3 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
AX88180 Gigabit Ethernet Controller Application Design Note
Figures
Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Clock Source from Gigabit PHY RGMII Interface Reference Connection................................... 7 Clock Source from Oscillator RGMII Interface Reference Connection........................................ 7 An Example of 4-Layer PCB Design .......................................................................................... 11 Typical Chassis/Digital Ground Planes for Single RJ-45 with Integrated Magnetic................... 12 Typical Chassis/Digital Ground Planes for Separated RJ-45 and Magnetic................................ 12 Typical Digital/Analog Power Planes for Single RJ-45 with Integrated Magnetic ..................... 13 Typical Digital/Analog Power Planes for Separate RJ-45 and Magnetic.................................... 13 An Example of AX88180 Power Pins and Decoupling Capacitors Circuits ............................... 14 Gigabit Ethernet MDI0±, MDI1±, MDI2±, and MDI3± Differential Pairs Layout..................... 15 AX88180 On-Chip Regulator Disabled Reference Circuit ......................................................... 17 An Example of Single RJ-45 Connector Magnetic Circuit for ESD Considerations .................. 20
5 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
AX88180 Gigabit Ethernet Controller Application Design Note
2. EEPROM Selection Considerations
2 Copyright (C) 2008 Reserved by ASIX Electronics Corporation
AX88180 Gigabit Ethernet Controller Application Design Note
Content
1. Introduction ..........................................................................................5 2. EEPROM Selection Considerations....................................................6 3. Crystal Selection Considerations.........................................................7 4. Ethernet Magnetic Selection Considerations .....................................9 5. 4-Layer PCB Design ...........................................................................11 6. Power and Ground Planes Considerations.......................................12 7. Ethernet Magnetic Layout Considerations ......................................15 8. Thermal Considerations.....................................................................17