Technical Note

7/14

BU9795AKV,BU9795AFV,BU9795AGUW,BU9794AKV,BU97950FUV

www.rohm.com

2011.03 - Rev.A

© 2011 ROHM Co., Ltd. All rights reserved.

LCD

BIAS

SELECTOR

common

driver

Segment

driver

OSCILLATOR

Power On Reset

SD

SCL

VLCD

OSCIN

VSS

COM0……COM3

SEG4……SEG30

IF FILTER

serial inter face

Command

register

common

counter

DDRAM

LCD voltage generator

Command

Data Decoder

blink timing

generator

＋

－

＋

－

VDD

CSB

TEST

INHb

1

20

21

40

<BU9795AFV>

●Block Diagram

●Pin Arrangement

Fig.6 Block Diagram (BU9795AFV)

Fig.7 Pin Arrangement (BU9795AFV)

●Terminal Description

Terminal

Terminal No.

I/O

Function

INHb

36

I

Input terminal for turn off display

H: turn on display

L: turn off display

TEST

35

I

Test input (ROHM use only)

Must be connect to VSS

OSCIN

31

I

External clock input

Ex clock and Int clock can be changed by command.

Must be connect to VSS when use internal oscillation circuit.

SD

34

I

serial data input

SCL

33

I

serial data transfer clock

CSB

32

I

Chip select : “L” active

VSS

30

-

GND

VDD

29

-

Power supply

VLCD

28

-

Power supply for LCD driving

SEG4-30

1-23,

37-40

O

SEGMENT output for LCD driving

COM0-3

24-27

O

COMMON output for LCD driving