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Apple Display Connector

The Apple Display Connector (ADC) carries both digital and analog video signals. It also carries USB and control signals along with power for an external monitor such as the 17-inch Apple Studio Display, the 15-inch plat-panel Apple Studio Display, or the 22-inch Apple Cinema Display.

Figure 3-3 shows the contact configuration; Table 3-6 and Table 3-7 list the signals and pin assignments.

Figure 3-3  Apple Display Connector

 

Table 3-6   Digital signals on the Apple display connector

Pin

Signal name

Pin

Signal name

1 28-V Supply 16 TMDS Data1/3 Shield
2 28-V Supply 17 TMDS Data3-
3 LED 18 TMDS Data3+
4 TMDS Data0- 19 DDC CLock
5 TMDS Data0+ 20 Clock Return
6 TMDS Data0/5 Shield 21 USB Data+
7 TMDS Data5- 22 USB Data-
8 TMDS Data5+ 23 USB Return
9 DDC Data 24 TMDS Data2-
10 Vsync 25 TMDS Data2+
11 28-V Return 26 TMDS Data2/4 Shield
12 28-V Return 27 TMDS Data4-
13 Soft Power 28 TMDS Data4+
14 TMDS Data1- 29 Clock+
15 TMDS Data1+ 30 Clock-

 

Table 3-7   Analog signals on the Apple display connector

Pin

Signal name

C1 Analog Blue Video
C2 Analog Green Video
C3 Analog Horizontal Sync
C4 Analog Red Video
C5 Analog RGB Return and DDC Return

The maximum current available from the 28-V supply for the external monitor is 4.0 A.

The Soft Power signal puts the monitor into a low-power mode when the computer is in Sleep mode.

The graphics data sent to the digital monitor use transition minimized differential signaling (TMDS). TMDS uses an encoding algorithm to convert bytes of graphics data into characters that are transition-minimized to reduce EMI with copper cables and DC-balanced for transmission over fiber optic cables. The TMDS algorithm also provides robust clock recovery for greater skew tolerance with longer cables or low cost short cables. For additional information about TMDS, see the references in Digital Visual Interface.


© 2000 Apple Computer, Inc. (Last Updated 04 Oct 00)