BU97950FUV Datasheet, PDF (16/25 Pages) Rohm – Standard LCD Segment Drivers

BU97950FUV MAX 280 segments (SEG35×COM8)
●Caution in P.O.R circuit use
This device has “P.O.R.” (Power-On Reset) circuit and Software Reset function.
Please keep the following recommended Power-On conditions in order to power up properly.
Please set power up conditions to meet the recommended tR, tF, tOFF, and Vbot spec below in
order to ensure P.O.R. operation
VDD
tF
tR
tOFF
Vbot
Recommended condition of tR, tF, tOFF, Vbot (Ta=25 ºC)
tR
tF
tOFF
Vbot
Less than Less than More than Less than
5ms
5ms
20ms
0.3V
Figure 12. Power ON/OFF waveform
If it is difficult to meet above conditions, execute the following sequence after Power-On.
(1) STOP condition
VDD
SDA
SCL
STOP condition
Figure 13. STOP condition
(2) START condition.
(3) Issue Slave address.
(4) Execute Software Reset (ICSET) command.
●Power Up Sequence and Power Down Sequence
To prevent incorrect display, malfunction and abnormal current,
VDD must be turned on before VLCD In power up sequence.
VDD must be turned off after VLCD In power down sequence.
Please satisfies VLCD≥VDD, t1>0ns, t2>0ns
t1
t2
VLCD
VDD
10%
VDD min
10%
VDD min
Figure 14. Power On/Off Sequence
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08.Sep.2015 Rev.004