Technical Note

3/11

BU9796FS

www.rohm.com

2009.05 - Rev.A

© 2009 ROHM Co., Ltd. All rights reserved.

LCD

BIAS

SELECTOR

common

driver

Segment

driver

OSCILLATOR

Pow er On Reset

SDA

SCL

VLCD

OSCIN

VSS

COM0……COM3

SEG0……SEG19

IF FILTER

serial inter face

Command

register

common

counter

DDRAM

LCD voltage generator

Command

Data Decoder

blink timing

generator

＋

－

＋

－

VDD

●Block Diagram

● Pin Arrangement

Fig. 2 block diagram

Fig. 3

Pin arrangement

●Terminal description

Terminal

Terminal

No.

I/O

Function

TEST1

26

I

Test input (ROHM use only)

Must be connect to VSS

TEST2

27

I

Test input (ROHM use only)

TEST2=”L”: POR circuit enable

TEST2=”H”: POR circuit disenable,

refer to “Cautions in Power ON/OFF”

OSCIN

28

I

External clock input

Ext clock and Int clock can be changed by command.

Must be connect to VSS when use internal oscillation circuit.

SDA

30

I/O

serial data in-out terminal

SCL

29

I

serial data transfer clock

VSS

25

GND

VDD

24

Power supply

VLCD

23

Power supply for LCD driving

SEG0-19

31,32

1-18

O

SEGMENT output for LCD driving

COM0-3

19-22

O

COMMON output for LCD driving