ROHM BU9718KV Datasheet
1
Standard ICs
Picture cell driver for STN (LCD driver)
for low voltage power supplies
BU9718KV
The BU9718KV is a driver IC designed for the character-type STN liquid crystal panels which are ideal for applications such as portable devices. The number of display segments includes 32 output segments and 3 common outputs, enabling drive of up to 96 segments. A compact 48-pin QFP package with a pitch of 0.5 mm is used, enabling
compact size for the set as a whole.
•
Features
1) Operates on 3V power supply.
2) Low current dissipation. (0.1µA in low power mode
(actual value))
3) Compact package. (molded section is 7.0 mm
ⵧ
)
4) Up to 32 segment output pins and 3 common output
pins are provided, enabling a total display of up to
96 segments.
5) 1 / 3 duty display.
6) Either 1 / 2 or 1 / 3 bias can be selected for power supplyfor LCD display.
•
Applications
Portable terminals (POS, ECR, PDA, and others),
movie projectors, cameras, telephones (cordless hand-
held telephone units), and others Low-voltage power
supply sets
•
Absolute maximum ratings (Ta = 25°C, VSS = 0V)
Parameter
Power supply voltage
∗
1
Input voltage
∗
1
Output voltage
∗
1
Output current
V
DD
VIN
VOUT
ISO
– 0.3 ~ + 7.0
– 0.3 ~ V
DD + 0.3
– 0.3 ~ V
DD + 0.3
300
V
Symbol
V
DD
OSC, CS, CK, DI, RES
OSC
S
1 ~ S32
Pin Limits Unit
V
V
µA
ICO 3COM1 ~ COM3 mA
Power dissipation Pd 400
∗
2
—mW
Storage temperature Tstg – 55 ~ + 125— °C
∗
1 Max. voltage that can be applied with a VSS pin
∗
2 Reduced by 4.0mW for each increase in Ta 1°C over 25°C.
•
Recommended operating conditions (Ta = 25°C, VSS = 0V)
Parameter
Power supply voltage
∗
VDD V
Symbol
VDD
Pin
2.7
Min.
—
Typ.
3.5
Input voltage
∗
Oscillation freq., with
external input
V
DD1 VVDD1 0 2 / 3 VDD VDD
VDD2 VVDD2 0 1 / 3 VDD VDD
fOSC kHzOSC — 38 100
External resistance R kΩOSC — 47 —
External capacitance C pFOSC — 1000 —
Operating temperature Topr °C— – 40 — 85
Max. Unit
∗
Indicates the max. voltage that can be applied with a VSS pin.
2
Standard ICs BU9718KV
•
Block diagram
Segment Driver
Data Latch
CTRL Logic
OSC
Common Driver
V
DD1
VDD2
RES
DI
CS
CK
OSC
COM1
COM2
COM3
S1
S2
S3
S4
S30
S31
S32
LCD Power
•
Pin assignments
VQFP48
36 25
121
37
48
24
13
COM1
S32
S31
S30
S29
S28
S27
S26
S25
S24
S23
N.C.
S
1
S2
S3
S4
S5
S6S7S8
S9
S10
S11
N.C.
COM2
COM3
RES
V
DD
VDD1
VDD2
VSS
OSC
CS
CK
DI
N.C.
N.C.
S
22
S21
S20
S19
S18
S17
S16
S15
S14
S13
S12
3
Standard ICs BU9718KV
•
Pin descriptions
Pin No.
1—11
13—23
26—35
Pin name
S
23—S32
S12—S22
S1—S11
Segment data output pin; outputs LCD drive voltage that
matches COM
1 - COM3 compatible data
I / O
O
Function Processing when not in use
44 OSC — Oscillation pin (for common, segment alternation waves) VSS
45 CS I Chip segment input; when CS = H, data can be transferred VSS
46 CK I Synchronous clock input for serial data transfer VSS
47 DI I Serial data input VSS
OPEN
36
37
38 COM
3
COM2
COM1
Common drive output; frame freq. fC = (fOSC / 384) HzO
V
SS
39
I
VDD
RES
Reset input; when RES = L, resets internal data
(include. control data)
41
—
OPEN
V
DD1
Internal standard voltage for liquid-crystal drive; when using
1 / 2 bias mode, connects to V
DD2
42
—
OPEN
V
DD2
Internal standard voltage for liquid-crystal drive; when using
1 / 2 bias mode, connects to V
DD1
•
Electrical characteristics (unless otherwise noted, Ta = 25°C, VDD = 2.7V to 3.5V, VSS = 0V)
Parameter Symbol Min. Typ. Max. Unit Conditions Pin
Input high level voltage VIH 0.8 VDD —VDD V — CS, CK, DI, RES
CS, CK, DI, RES
CS, CK, DI, RES
CS, CK, DI, RES
Input low level voltage VIL 0 — 0.2 VDD V—
Input high level current IIH 0 — 6.0 µAVI = VDD
Input low level current IIL 0 — 6.0 µAVI = VSS
Output high level voltage
V
SOH —VDD – 1.0 — V IO = – 20µAS1 ~ S32
VCOH —VDD – 1.0 — V IO = – 100µA COM1 ~ COM3
Output low level voltage
Output medium level voltage
V
SOL — 1.0 — V IO = 20µAS1 ~ S32
VCOL — 1.0 — V IO = 100µA COM1 ~ COM3
Power supply current
I
Q — 0.1 30 µA Low-power mode —
IDD — 100 300 µAfOSC = 38kHz —
V
CM1 —
1 / 2 V
DD
± 1.0
— V 1 / 2bias COM
1 ~ COM3
VSM1 —
2 / 3 V
DD
± 1.0
— V 1 / 3bias S
1 ~ S32
VCM2 —
2 / 3 V
DD
± 1.0
— V 1 / 3bias COM
1 ~ COM3
VSM2 —
1 / 3 V
DD
± 1.0
— V 1 / 3bias S
1 ~ S32
VCM3 —
1 / 3 V
DD
± 1.0
— V 1 / 3bias COM
1 ~ COM3
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