BU9795AKV Datasheet, PDF (12/16 Pages) Rohm – Standard function Segment Drivers

BU9795AKV, BU9795AFV, BU9795AGUW
Technical Note
● Cautions of Power-On condition
This LSI 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.
1. 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
tOFF
tR
Vbot
Recommendation condition of tR,tF,tOFF,Vbot
tR
tF
tOFF
Vbot
Less than 1ms Less than 1ms More than Less than 0.1V
150ms
Power
ON/OFF
Fig. 5 Power on-off waveform
2. If it is difficult to meet above conditions, execute the following sequence after Power-On.
Because it doesn’t accept the command in power off, it is necessary to care that correspondence
by software reset doesn’t become alternative to POR function completely.
(1) CSB=”L”→”H” condition
VDD
CS B
Fig. 6 CSB Timing
(2) After CSB”H”→“L”, execute Software Reset (ICSET command).
● IO Circuit (BU9795AKV /AFV /AGUW)
VDD
VLCD
VDD
TEST
VSS
VSS
VDD
CSB, SD, SCL
VSS
VDD
OSCIN
VSS
VDD
INHb
VSS
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VDD
VSS
Fig. 7 IO circuit
12/15
2009.07 - Rev.B