Advantech SOM-Express Design Guide
Table of Contents 7
Figure 5-53 Example of SATA trace length pair matching............86
5.12 LPC........................................................................................................87
5.12.1 Signal Description.........................................................................87
Table 5-32 LPC signals description..............................................87
5.12.2 Design Guidelines.........................................................................87
Table 5-33 Recommended Pull-Up Values ..................................87
5.12.3 Layout Guidelines.........................................................................87
5.12.4 Application Notes..........................................................................88
Figure 5-54 Architecture of LPC interface ....................................88
Figure 5-55 Serial Bus Connection...............................................88
Figure 5-56 Keyboard and Mouse connection..............................89
Figure 5-57 LPT Connection.........................................................90
Figure 5-58 Floppy Connection ....................................................91
Chapter 6 Power Delivery Guidelines .................................................................92
6.1 SOM-Express Power Consumption.......................................................92
Table 6.1 SOM-5780 Power Consumption ................................92
6.2 Design Guidelines .................................................................................95
6.2.1 ATX Power Delivery Block Diagram .............................................95
Figure 6-1 ATX Power Delivery Block Diagram............................95
6.2.2 AT Power Delivery Block Diagram................................................96
Figure 6-2 AT Power Delivery Block Diagram ..............................96
Chapter 7 Carrier Board Mechanical Design Guidelines...................................97
7.1 SOM-Express Mechanical Dimensions .................................................97
Figure 7-1: SOM-Express Module Board Mechanical Dimensions
......................................................................................................
97
7.2 SOM Express Module Connector ..........................................................98
Figure 7-2: SOM-Express Module Receptacle .............................98
7.3 SOM Express Carrier Board Connector ................................................98
Figure 7-3: SOM-Express Carrier Board Plug (8mm Version) .............99
7.4 SOM Express Connector PCB Pattern..................................................99
Figure 7-4: SOM-Express Connector PCB Pattern..............................99
7.5 SOM Express Module Connector Pin Numbering ...............................100
Figure 7-5: SOM-Express Module Connector Pin Numbering ...........100
7.6 SOM-Express Carrier Board Connector Pin Numbering .....................100
Figure 7-6: SOM-Express Carrier Board Connector Pin Numbering...100
Chapter 8 Heatsink Recommended Design......................................................101
8.1 Material of Heatsink.............................................................................101
8.2 Thermal Interface Material...................................................................101
8.3 Attachment Method of Thermal Solution .............................................102
8.4 Grounding Issues ................................................................................102
8.5 Air intake clearance and Airflow of Heatsink .......................................102
Figure 8-1: Air Intake Clearance.................................................102
Figure 8-2: Air Flow Direction .....................................................103
8.6 SOM-Express Thermal solution Specification .....................................103
Figure 8-3: Overall Height for Heat-Spreader in SOM-Express
Modules ......................................................................................
103
Figure 8-4: SOM-Express Module Heat-Spreader......................105
8.7 Component Height – Module Back and Carrier Board Top .................105
Figure 8-5: Component Clearances Underneath Module ...........105
8.8 Advantech Heatsink Information..........................................................106
8.8.1 Vendor List..................................................................................106
Table 8.1: Vendor list..................................................................106
8.8.2 Heat-Spreader ............................................................................106
Figure 8-6: SOM-Express Heat-Spreader.........................................106
Figure 8-7: SOM-Express Heat-Spreader Tolerances ........................107
