SED1565 Datasheet, PDF (46/87 Pages) Epson Company – Direct display of RAM data through the display data RAM

SED1565 Series
* When the V5 voltage regulator internal resistors or
the electronic volume function is used, it is necessary
to at least set the voltage regulator circuit and the
voltage follower circuit to an operating mode using
the power control set commands. Moreover, it is
necessary to provide a voltage from VOUT when the
Booster circuit is OFF.
* The VR terminal is enabled only when the V5 voltage
regulator internal resistors are not used (i.e. the IRS
terminal = “L”). When the V5 voltage regulator
internal resistors are used (i.e. when the IRS terminal
= “H”), then the VR terminal is left open.
* Because the input impedance of the VR terminal is
high, it is necessary to take into consideration short
leads, shield cables, etc. to handle noise.
The Liquid Crystal Voltage Generator Circuit
The V5 voltage is produced by a resistive voltage
divider within the IC, and can be produced at the V1, V2,
V3, and V4 voltage levels required for liquid crystal
driving. Moreover, when the voltage follower changes
the impedance, it provides V1, V2, V3 and V4 to the
liquid crystal drive circuit. 1/9 bias or 1/7 bias for
SED1565 Series, 1/8 bias or 1/6 bias for SED1566
Series and 1/6 bias or 1/5 bias for the SED1567 Series
can be selected.
High Power Mode
The power supply circuit equipped in the SED1565
Series chips has very low power consumption (normal
mode: HPM = “H”). However, for LCDs or panels with
large loads, this low-power power supply may cause
display quality to degrade. When this occurs, setting the
HPM terminal to “L” (high power mode) can improve
the quality of the display. We recommend that the
display be checked on actual equipment to determine
whether or not to use this mode.
Moreover, if the improvement to the display is inadequate
even after high power mode has been set, then it is
necessary to add a liquid crystal drive power supply
externally.
The Internal Power Supply Shutdown
Command Sequence
The sequence shown in Figure 22 is recommended for
shutting down the internal power supply, first placing
the power supply in power saver mode and then turning
the power supply OFF.
Sequence
Details
(Command, status)
Command address
D7 D6 D5 D4 D3 D2 D1 D0
Step1
Step2
Display OFF
Display all points ON
10101110
10100101
Power saver
commands
(compound)
End
Internal power supply OFF
Figure 22
8–44
EPSON