BU9796AFS-E2 Datasheet, PDF (22/32 Pages) Rohm – Standard LCD Segment Driver

BU9796Axxx Series MAX 80 segments (SEG20×COM4)
Datasheet
●Cautions in Power ON/OFF
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
*It has to set TEST1=”L” to be valid in POR circuit.
VDD
tF
tR
tOFF
Vbot
Recommended condition of tR, tF, tOFF, Vbot (Ta=25℃)
tR
tF
tOFF
Vbot
Less than Less than More than Less than
1ms
1ms
100ms
0.1V
Figure 23. Power ON/OFF waveform
If it is difficult to meet above conditions, execute the following sequence after Power-On.
* It has to keep the following sequence in the case of TEST2=”H”. As POR circuit is invalid status.
But it is not able to accept Command input in Power off status, it has to take care that software reset is not perfectly
alternative method of POR function.
(1) Generate STOP condition
(2) Generate START condition.
Figure 24. Stop Condition
Figure 25. Start Condition
(3) Issue slave address
(4) Execute Software Reset (ICSET) command
www.rohm.com
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111ï½¥15ï½¥001
22/28
TSZ02201-0A2A0D300100-1-2
13.Jun.2014 Rev.003