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
