SED1374 Datasheet, PDF (249/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

Epson Research and Development
Vancouver Design Center
Page 17
6.10 Power Save Modes
The SED1374 supports one hardware and one software power save mode. These modes are
controlled by the utility 1374PWR. The hardware power save mode needs to be enabled by
1374PWR and then activated by DIP switch SW1-6. See Table 2-1: “Configuration DIP
Switch Settings,” on page 8 for details on setting this switch.
6.11 Adjustable LCD Panel Negative Power Supply
Most monochrome passive LCD panels require a negative power supply to provide
between -18V and -23V (I_out=45mA). For ease of implementation, such a power supply has
been provided as an integral part of this design. The VLCD power supply can be adjusted
by R21 to give an output voltage from -14V to -23V, and is enabled/disabled by the
SED1374 control signal LCDPWR.
LCDPWR is an SED1374 output signal which is configurable as active high or active low
by the CNF4 signal status on the rising edge of the RESET# signal. For the proper operation
of the VLCD power supply, LCDPWR must be configured as active low.
Determine the panel’s specific power requirements and set the potentiometer accordingly
before connecting the panel.
6.12 Adjustable LCD Panel Positive Power Supply
Most color passive LCD panels and most single monochrome 640x480 passive LCD panels
require a positive power supply to provide between +23V and +40V (I_out=45mA). For ease
of implementation, such a power supply has been provided as an integral part of this design.
The V_DDH power supply can be adjusted by R15 to provide an output voltage from +23V
to +40V and is enabled/disabled by the SED1374 control signal LCDPWR.
LCDPWR is an SED1374 output signal which is configurable as active high or active low
by the CNF4 signal status on the rising edge of the RESET# signal. For the proper operation
of the VDDH power supply, LCDPWR must be configured as active low.
Determine the panel’s specific power requirements and set the potentiometer accordingly
before connecting the panel.
SDU1374B0C Rev. 1.0 ISA Bus Evaluation Board User Manual
Issue Date: 98/10/26
SED1374
X26A-G-005-01