BU9795AKS2 Datasheet, PDF (27/40 Pages) Rohm – Standard LCD Segment Drivers

BU9795Axxx Series MAX 140 segments (SEG35×COM4)
Datasheet
●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.
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
Recommended condition of tR,tF,tOFF,Vbot
tR
tF
tOFF
Vbot
Less than Less than More than Less than
tOFF
Vbot
1ms
1ms
150ms
0.1V
Figure 31. Power on-off waveform
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
CSB
Figure 32. CSB Timing
(2) After CSB”H”→”L”, execute Software Reset (ICSET command).
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111ï½¥15ï½¥001
27/37
TSZ02201-0A0A2D300020-1-2
12.July.2012 Rev.002