BU9794KV Datasheet, PDF (3/23 Pages) Rohm – For 200 Segment type LCD LCD Segment Driver

● Block Diagram （BU9794KV）
VLCD
LCD voltage generator
COM0……COM3
SEG0……SEG49
common
driver
Segment
driver
＋
－
LCD
BIAS
SELECTOR
＋
common blink timing
DDRAM
counter
generator
－
INHb
OSCIN
VDD
VSS
VSS
OSCILLATOR
Power On Reset
Command
register
Command
Data Decoder
serial inter face
IF FILTER
TEST2 TEST1
CSB
SD
SCL
Fig. BU9794KV-2 Block diagram
●Pin Arrangement （BU9794KV）
49
SEG38
SEG39
SEG40
SEG41
SEG42
SEG43
SEG44
SEG45
SEG46
SEG47
SEG48
SEG49
COM0
COM1
COM2
COM3
64
32
SEG21
SEG20
SEG19
SEG18
SEG17
SEG16
SEG15
SEG14
SEG13
SEG12
SEG11
SEG10
SEG9
SEG8
SEG7
SEG6
17
Fig. BU9794KV-3 Pin arrangement
● Terminal description （BU9794KV）
Terminal
Terminal
No.
I/O
INHb
8
I
TEST1
9
I
TEST2
10
I
OSCIO
SD
SCL
CSB
VSS
VDD
VLCD
SEG0-49
COM0-3
4
I
7
I
6
I
5
I
3
2
1
11-60 O
61-64 O
Function
Input terminal for turn off display
H: turn on display L: turn off display
Test input (ROHM use only)
Must be connect to VSS
Test input (ROHM use only)
Must be connect to VSS
External clock input
Ex clock and Int clock can be changed by command.
Must be connect to VSS when use internal oscillation circuit.
serial data input
serial data transfer clock
Chip select : “L” active
GND
Power supply
Power supply for LCD driving
SEGMENT output for LCD driving
COMMON output for LCD driving
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