ROHM BU9795AKV Technical data

LCD Segment Drivers

Standard
Segment Drivers

BU9795AKV/FV/GUW,BU9794AKV,BU97950FUV/KS2

No.11044EBT06

●Description

ROHM standard function segment driver series achieve “Ultra-Low power consumption”. Also these drivers need not
external components. And this driver series is very simple that only has segment driver function. So, these driver series are
very suitable to add in LCD display function for various applications.

●Features (BU9795AKV/FV/GUW, BU9794AKV)

1) 3wire serial interface

2) Integrated RAM for display data (DDRAM)

3) Power supply circuit for LCD driving
1/2, 1/3Bias selectable
1/4Duty
Integrated Buffer AMP

4) Integrated Oscillation circuit

5) Integrated Power-on Reset circuit

6) No external components

7) Support blink function

8) Support standby mode

9) Low voltage / Ultra low power consumption design

10) Support unity voltage supply (BU9795AKV/FV/GUW)

11) Support Independent power supply circuit for LCD driving (BU9794AKV)

●Features (BU97950FUV/KS2)

1) 2wire serial interface

2) Integrated RAM for display data (DDRAM)

3) Integrated Power supply circuit for LCD driving
1/4 Bias 1/8 Duty
Integrated Buffer AMP

4) Integrated Oscillation circuit

5) Integrated Power-on Reset circuit

6) No external components

7) Support standby mode

8) Low voltage / Ultra low power consumption design

9) Integrated Electrical volume register (EVR) function

10) Support Register Read function

11) Support Independent power supply circuit for LCD driving

●Applications

Telephone, FAX, Portable equipment (POS, ECR, PDA etc.),
DSC, Digital video camera, Home electrical appliance, Meter equipment, Healthcare equipment etc.

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

1/15

2011.11 - Rev.B

BU9795AKV/FV/GUW,BU9794AKV,BU97950FUV/KS2

Technical Note

●Line up matrix

Parameter

KV FV GUW FUV KS2

BU9795A

Segment output 35 27

Common output 4 4
Total display

dot number

140 108 124 200 280 280

31

4

BU9794AKV

50 35 35

4 8 8

BU97950

Adjustable contrast function - - - - Yes Yes

Support split voltage supply - - - Yes Yes Yes

Interface 3wire 3wire 3wire 3wire 2wire 2wire

Package VQFP48C SSOP-B40

VBGA48W040

VQFP64 TSSOP-C48V SQFP-T52

●Absolute maximum ratings (VSS=0V)

Parameter

BU9795AKV

/FV/GUW

BU9794AKV

BU97950FUV

/KS2

Unit

Remarks

Power Supply Voltage 1
(VDD)

Power Supply Voltage 2
(VLCD)

Allowable Loss
(Pd)

-0.5～VDD -0.5～+7.0 -0.5～+7.0 V

0.6*1

2

0.7*

3

0.27*

Input Voltage Range
(VIN)

Operational Temperature Range
(Topr)

Storage Temperature Range
(Tstg)

*1 When use more than Ta=25°C, subtract 6.0mW per degree (BU9795AKV)
*2 When use more than Ta=25°C, subtract 7.0mW per degree (BU9795AFV)
*3 When use more than Ta=25°C, subtract 2.7mW per degree (BU9795AGUW)
*4 When use more than Ta=25°C, subtract 7.5mW per degree (BU9794AKV)
*5 When use more than Ta=25°C, subtract 6.4mW per degree (BU97950FUV)
*6 When use more than Ta=25°C, subtract 8.5mW per degree (BU97950FUV)

●Recommend operating conditions (Ta=-40~85°C, VSS=0V)

Parameter

BU9795AKV

/FV/GUW *

7

MIN TYP MAX MIN TYP MAX MIN TYP MAX

Power Supply Voltage 1
(VDD)

2.5 - 5.5 2.5 - 5.5 2.5 - 5.5 V Power supply

-0.5～+7.0

Power supply

V

LCD drive
Voltage

0.75*

4

0.64*5

*6

0.85

Allowable loss

W

at package only

-0.5～VDD+0.5 V

-40～+85 ℃

-55～+125 ℃

BU9794AKV BU97950KV/KS2

Unit Remarks

Power Supply Voltage 2
(VLCD)

*7 Please use VDD-VLCD  2.4V condition.

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

0 -

VDD

-2.4

2.5 - 5.5 2.5 - 5.5 V

2/15

LCD drive
Voltage

2011.11 - Rev.B

BU9795AKV/FV/GUW,BU9794AKV,BU97950FUV/KS2

●Electrical characteristics

<BU9795AKV/FV/GUW>
DC Characteristics (VDD=2.5~5.5V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

MIN TYP MAX

Limits

Unit Condition

“H” level input voltage VIH 0.7VDD - VDD V SD, SCL, CSB

“L” level input voltage VIL VSS - 0.3VDD V SD, SCL, CSB

“H” level input current IIH - - 1 µA SD, SCL, CSB

“L” level input current IIL -1 - - µA SD, SCL, CSB

LCD Driver
on resistance

SEG RON - 3.5 - kΩ

COM RON - 3.5 - kΩ

Iload=±10µA

VLCD supply voltage VLCD 0 - VDD -2.4 V VDD-VLCD  2.4V

Standby current Ist - - 5 µA Display off, Oscillator off

VDD=3.3[V], Ta=25°C,

Power consumption 1 IDD1 - 12.5 30 µA

Power save mode1, FR=70Hz
1/3 bias, Frame inverse

VDD=3.3[V], Ta=25°C,

Power consumption 2 IDD2 - 20 40 µA

Normal mode, FR=80Hz
1/3 bias, Line inverse

Oscillation Characteristics (VDD=2.5~5.5V，VSS=0V, Ta=-40~85C)

Parameter Symbol

MIN TYP MAX

Limits

Unit Condition

Frame frequency fCLK 56 80 104 Hz FR = 80Hz setting

Frame frequency1 fCLK1 70 80 90 Hz

VDD=3.5V, 25C

MPU interface Characteristics(VDD=2.5V~5.5V，VSS=0V, Ta=-40~85C)

Parameter Symbol

MIN TYP MAX

Limits

Unit Condition

Input rise time tr - - 80 ns

Input fall time tf - - 80 ns

SCL cycle time tSCYC 400 - - ns

“H” SCL pulse width tSHW 100 - - ns

“L” SCL pulse width tSLW 100 - - ns

SD setup time tSDS 20 - - ns

SD hold time tSDH 50 - - ns

CSB setup time tCSS 50 - - ns

CSB hold time tCSH 50 - - ns

“H” CSB pulse width tCHW 50 - - ns

CSB

SCL

SD

tCSS

tf

tSLW

tSDS

tSDH

tSCYC

tSHW

tr

tCSH

Fig.1 Interface Timing (BU9795AKV/FV/GUW)

Technical Note

tCHW

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3/15

2011.11 - Rev.B

BU9795AKV/FV/GUW,BU9794AKV,BU97950FUV/KS2

ftr

Technical Note

<BU9794AKV>
DC Characteristics (VDD=2.5~5.5V, VLCD=2.5~5.5V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

MIN TYP MAX

Limits

Unit Condition

“H” level input voltage VIH 0.8VDD - VDD V SD,SCL,CSB

“L” level input voltage VIL VSS - 0.2VDD V SD,SCL,CSB

“H” level input current IIH - - 1 µA SD,SCL,CSB

“L” level input current IIL -1 - - µA SD,SCL,CSB

LCD Driver
on resistance

SEG RON - 3.5 - kΩ

COM RON - 3.5 - kΩ

Iload=±10µA

Standby current Ist - - 5 µA Display off, Oscillation off

VDD=3.3V, VLCD=5V, Ta=25°C

Power consumption 1 IDD - 5 15 µA

Power save mode1, FR=70Hz
1/3 bias, Frame inverse

VDD=3.3V, VLCD=5V, Ta=25°C

Power consumption 2 ILCD - 10 20 µA

Power save mode1, FR=70Hz
1/3 bias, Frame inverse

Oscillation Characteristics (VDD=2.5~5.5V, VLCD=2.5~5.5V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

MIN TYP MAX

Limits

Unit Condition

Frame frequency fCLK 68 80 92 Hz FR = 80Hz setting, VDD=3.3V

MPU interface Characteristics (VDD=2.5~5.5V, VLCD=2.5~5.5V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

MIN. TYP. MAX.

Limits

Unit Condition

Input rise time tr - - 80 ns

Input fall time tf - - 80 ns

SCL cycle time tSCYC 400 - - ns

“H” SCL pulse width tSHW 100 - - ns

“L” SCL pulse width tSLW 100 - - ns

SD setup time tSDS 20 - - ns

SD hold time tSDH 50 - - ns

CSB setup time tCSS 50 - - ns

CSB hold time tCSH 50 - - ns

“H” CSB pulse time tCHW 50 - - ns

tCHW

CSB

tCSS

tCSH

SCL

t

tSLW

tSDS

tSCYC

tSHW

tSDH

SD

Fig.2 Interface Timing (BU9794AKV)

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

4/15

2011.11 - Rev.B

BU9795AKV/FV/GUW,BU9794AKV,BU97950FUV/KS2

r

<BU97950FUV/KS2>
DC Characteristics (VDD=2.5~5.5V, VLCD=2.5~5.5V, VSS=0V, Ta=-40~85 ºC, unless otherwise specified)

Parameter Symbol

“H” level input voltage VIH 0.7VDD - VDD V SDA,SCL

“L” level input voltage VIL VSS - 0.3VDD V SDA,SCL

“H” level input current IIH - - 1 µA SDA,SCL

“L” level input current IIL -1 - - µA SDA,SCL

LCD Driver on
resistance

Standby current Ist - - 5 µA Display off, Oscillation off

Power consumption 1 IDD - 2.5 15 µA

Power consumption 2 ILCD - 10 20 µA

Oscillation Characteristics (VDD=2.5~5.5V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

Frame frequency fCLK 56 80 104 Hz Power save mode FR = Normal mode

MPU interface Characteristics (VDD=2.5~5.5V, VLCD=0V, VSS=0V, Ta=-40~85C, unless otherwise specified)

Parameter Symbol

Input rise time tr - - 0.3 µs

Input fall time tf - - 0.3 µs

SCL cycle time tSCYC 2.5 - - µs

“H” SCL pulse width tSHW 0.6 - - µs

“L” SCL pulse width tSLW 1.3 - - µs

SDA setup time tSDS 100 - - ns

SDA hold time tSDH 100 - - ns

Bus free time tBUF 1.3 - - µs

START condition hold time tHD;STA 0.6 - - µs

START condition setup time tSU;STA 0.6 - - µs

STOP condition setup time tSU;STO 0.6 - - µs

SDA

S CL

SDA

SEG RON - 3.5 - kΩ

COM RON - 3.5 - kΩ

t BUF

tHD;STA

MIN TYP MAX

MIN TYP MAX

MIN. TYP. MAX.

tSLW

t

Fig.3 interface timing (BU97950FUV)

Limits

Limits

Limits

tSU;STA

tr

tSDH

Unit Conditions

Iload=±10µA

VDD=3.3V, VLCD=5V, Ta=25 ºC
Power save mode1, FR=80Hz
1/4 bias, Frame inverse
VDD=3.3V, VLCD=5V, Ta=25 ºC
Power save mode1, FR=80Hz
1/4 bias, Frame inverse

Unit Condition

Unit Condition

tSHW

tf

tSDS

tSCYC

Technical Note

t SU;STO

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

5/15

2011.11 - Rev.B