Ampro Corporation 486E Computer Hardware User Manual


 
Product Reference
2–37
Table 2–31. J3 Mating Connectors
Part Description Mating Connector
Ribbon 3M 4325-7600
Discrete Wire MOLEX Housing 55-22-2502
PIN 16-02-0103
Power Sequencing
Some LCD panels 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 generates signals for sequencing the power in
the proper order to protect the panel from these effects. If an external power supply is connected,
special enabling signals ENVEE and ENVDD provided on the J3 connector must be used to enable
this supply.
As an option, Ampro provides a Vee bias supply board that will interface to the Little Board/486e
CPU through connector J4. This board contains circuitry to generate a Vee bias voltage that is
already properly sequenced.
Advanced Power Management
The same signals that support power sequencing also provide for power management. On-board
circuitry provides the following power management features in panel off mode:
! CRT - OFF
! FPD – OFF
! VGA subsystem registers and display memory - ON
In standby mode, the following occurs:
! CRT – OFF
! FPD Interface – OFF
! VGA Subsystem – OFF
! Screen DRAM – Low power mode (only DRAM is refreshed)