Specifications

Hardware Configuration
2–34
Connector Type Mating Connector
RIBBON 3M 4325-7600
DISCRETE WIRE MOLEX HOUSING 22-55-2502
PIN 16-02-0103
Table 2-25 J3 Mating Connectors
Flat Panel Shift Clock Polarity
Some flat panels require an inverted shift clock. A jumper, W23 is provided for this purpose. Set the
jumper block on W23 as shown in the following diagram.
Figure 2-12 Flat Panel Shift Clock Polarity Jumper (W23)
Power Sequencing
LCD flat panel displays can be damaged when the Vee bias supply is applied to the LCD substrate
without first enabling the control and data lines. This can result in damage to the panel or reduction of
its operational life. The video controller provides signals for sequencing the power in the proper
order to protect the panel from these effects. The Little Board/486i supports automatic sequencing of
Vdd (+5V) and +12V (for an external backlight power inverter). The Ampro LCD Bias Supply board
supports automatic power sequencing of Vee. If you use your own supply, you must enable the power
using the special enable signals provided on connector J3, ENAVEE, ENAVDD, and ENABKL. The
Ampro LCD Bias Supply board and circuits on the Little Board/486i, implement the power
sequencing feature using these signals. For more information, see the section “The LCD Bias Supply
Option.”
Advanced Power Management
Note that the same signals that support power sequencing are also used to provide the power
management feature. In “panel off mode” both the CRT and flat-panel interface are turned off, but
the VGA subsystem (registers and display memory) remain powered. In “standby mode”, the CRT
and flat-panel interfaces are turned off, and in addition, the VGA subsystem is turned off. The screen
DRAM is placed in a low-power mode in which only the DRAM is refreshed. To take advantage of
the power savings modes, you must implement the power switches using the special enable signals on
connector J3. The Ampro LCD Bias Supply option fully implements the advanced power
management features.
BIOS Support of Non-Standard Panels
Ampro supplies flat panel BIOS images for several popular LCD panels. You select the panel BIOS
using SETUP (see Chapter 3). If you select an unsupported panel, you must modify the standard
BIOS to support the panel. Ampro can provide a BIOS modification kit to do this. Contact your
Ampro sales representative or Ampro Technical Support for information about the Little Board/486i
Flat Panel BIOS Modification Kit.