BU91R63CH-M3BW Datasheet, PDF (28/37 Pages) Rohm – Low Duty LCD Segment Driver

BU91R63CH-M3BW Max 176 segments (SEG44 x COM4)
Cautions in Power ON/OFF
Please keep Power ON/OFF sequence as below waveform.
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 t1>0ns, t2>0ns
t1
t2
VLCD
10%
10%
VDD
VDD min
VDD min
Figure 30. Recommended Power ON/OFF Sequence
BU91R63CH-M3BW has “P.O.R” (Power-On Reset) circuit and Software Reset function.
Keep the following recommended Power-On conditions in order to power up properly.
Set power up conditions to meet the recommended tR, tF, tOFF, and Vbot specification below in order to ensure P.O.R
operation.
Set pin T0=VSS to enable POR circuit.
VDD
tF
tR
tOFF
Vbot
Figure 31. Power ON/OFF Waveform
Recommended condition of tR, tF, tOFF, Vbot (Ta=25°C)
tR^(Note)
tF^(Note)
tOFF^(Note) Vbot^(Note)
1ms
to 500ms
1ms
to 500ms
Min 20ms
Less than
0.1V
(Note) This function is guaranteed by design, not tested in production process.
If it is difficult to keep above conditions, execute the following sequence as quickly as possible after Power-On.
Setting T0=VDD disables the POR circuit, in such case, execute the following sequence.
Note that however it cannot accept command while supply is unstable or below the minimum supply range.
Note also that software reset is not a complete alternative to POR function.
1. Generate STOP Condition
VDD
SDA
SCL
2. Generate START Condition.
STOP condition
Figure 32. Stop Condition
VDD
SDA
SCL
START condition
Figure 33. Start Condition
3. Issue Slave Address
4. Execute Software Reset (ICSET) Command
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TSZ22111・15・001
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TSZ02201-0P4P0D301380-1-2
10 Feb. 2016 Rev.001