Specifications

Little Board/P5i Technical Manual

2–36

Table 2–29 J3 Mating Connectors

Connector Type Mating Connector

RIBBON 3M 4325-7600

DISCRETE WIRE MOLEX HOUSING 55-22-2502

PIN 16-02-0103

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 Figure 2–8.

Figure 2–8 Flat Panel Shift Clock Polarity Jumper (W23)

Power Sequencing

Some LCD flat panel displays can be damaged when the V

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/P5i 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 V

. 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/P5i implement the power sequencing feature using

these signals. For more information, see “The LCD Bias Supply Option” on page 2–37.

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 J40. 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/P5i Flat Panel BIOS

Modification Kit.