BU9794AKV Datasheet, PDF (8/26 Pages) Rohm – Standard LCD Segment Driver

BU9794AKV MAX 200 Segments (SEG50×COM4)
○OSCILLATOR
There are two kinds of clock for logic and analog circuit; from internal oscillator circuit or external clock input. If internal
oscillator circuit will be used, OSCIN must be connected to VSS.
*When using external clock mode, it has to input external clock from OSCIN terminal after DISCTL command setting.
OSCIN
BU9794AKV
VSS
OSCIN
BU9794AKV
VSS
Clock input
Figure 10. Internal oscillator circuit mode
Figure 11. External clock input mode
○LCD Driver Bias Circuit
This device generates LCD driving voltage with on-chip Buffer AMP.
It can drive LCD at low power consumption.
*1/3 and 1/2Bias can set in DISCTL command.
*Line and frame inversion can set in MODESET command.
Refer to “LCD driving waveform” about each LCD driving waveform.
○Blink timing generator
This device has Blink function.
*This device will be Blink mode with BLKCTL command.
Blink frequency varies widely by characteristic of fCLK, when at internal oscillation circuit mode.
Refer to Oscillation Characteristics for more details on fCLK.
○Reset initialize condition
Initial condition after execute Software Reset is as follows.
・Display is OFF.
・DDRAM address is initialized (DDRAM Data is not initialized).
Refer to Command Description about initialize value of register.
●Command / Function List
Description List of Command / Function
No.
Command
1 Mode Set (MODESET)
2 Address Set (ADSET)
3 Display Control (DISCTL)
4 Software Reset (SWRST)
5 Blink Control (BLKCTL)
6 All Pixel Control (APCTL)
Function
Set LCD drive mode
Set LCD display mode 1
Set LCD display mode 2
Execute software reset
Set blink mode
Set pixel condition
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10.Apr.2015 Rev.004