UPD161401 Datasheet, PDF (107/124 Pages) NEC – 256-COLOR, 1/80-DUTY LCD CONTROLLER/DRIVER WITH ON-CHIP RAM

µPD161401
8.4 Power OFF Sequence (with External Driving Power Supply)
This is an example of inputting a reference voltage to the VRS pin and a driving voltage to the VOUT pin from an
external power supply.
Operation status
↓
Control register 1
DISP = 0, HALT = 0
R0
Display OFF. Internal operation starts.
↓
Power system control register 5
(HPM1, HPM0 = 1, 0)
Change the operation mode of the operational
R56
amplifier to “power OFF mode”.
5
↓
Wait for at least 300 ms until power is OFF ^Note.
Driving power supply OFF
Turn OFF driving voltage VOUT after the levels of VLCD
and VLC1 to VLC4 have completely dropped.
↓
Power OFF
Power to VDD1 and VDD2 OFF
Note The time of 300 ms varies depending on the characteristics of the LCD panel and the capacitance of the
smoothing capacitor. It is recommended to determine this value after thorough evaluation with the actual
system (refer to 8.5 Flow of VOUT and VLCD Voltages from Power ON to Power OFF).
Data Sheet S15726EJ2V0DS
107