Datasheet BA3899F Datasheet (ROHM)

1

Standard ICs

EL driver for portable sets

BA3899F

The BA3899F is an IC developed for EL drive applications. It uses a more compact interface than transformer sys­tems, and is ideal for use in thin sets.

•

Applications

Pagers, electronic notebooks and other portable devices

•

Block diagram

8

7

6

1 2

3

5

STBY

4

GND

N.C. C1

C2

SW1 SW2 V

CC STBY

OSC2

OSC1

R

SW2

•

Features

1) Drive oscillation frequency can be set using external capacitance.

2) Equipped with standby control pin.

•

Absolute maximum ratings (Ta = 25°C)

Parameter
Power supply voltage
Power dissipation
Operating temperature
Storage temperature

V

CC

Pd
Topr
Tstg

8.0

450

∗

– 10 ~ + 60
– 55 ~ + 125

V

Symbol Limits Unit

mW

°C
°C

Maximum applied voltage VST 8.0 V

∗

Reduced by 4.5mW for each increase in Ta of 1°C over 25°C.

•

Recommended operating conditions (Ta = 25°C)

Parameter

V

CC 1.0 5.0 7.0 V

Symbol Min. Typ. Max. Unit

Power supply voltage

2

Standard ICs BA3899F

•

Pin descriptions

V

CC

GND

C1

1k

V

CC

GND

C2

200Ω

V

CC

GND

SW2

50k

500Ω

X20X1

GND

STBY

1k

200k

50k

V

CC

GND

SW1

X5X1

Pin No.

OSC1 oscillator circuit;
external capacitor pin

OSC2 oscillator circuit;
external capacitor pin

Standby control pin
(HIGH state: standby cancelled)

SW2 switching output pin

SW1 switching output pin

䊊When applying resistance, etc.

to the STBY pin, be careful not
to exceed the threshold values.

—

—

2——N.C.

—V

CC

input pin

6I—V

CC

3 I / O —C1

4 I / O —C2

5I0STBY

7O—SW2

8O—SW1

1 I — — GND pinGND

Pin name I / O Pin voltage Internal equivalent circuit Function

3

Standard ICs BA3899F

•

Electrical characteristics (unless otherwise noted, Ta = 25°C, VCC = 5.0V, C1 = 0.033µF, C2 = 1500pF)

Parameter

Symbol Min. Typ.
Supply current ICC mA When used as stand-alone unit3.0 4.6 6.2
C1 pin oscillation frequency fSW1 Hz75 95 120
C2 pin oscillation frequency fSW2 kHz17 23 29

Source current

SW1

SW2

Standby pin control
voltage condition

ISW1SO µAVC1 = 1.0V, VC2 = 0.05V, VSW1 = 0V100 140 180
Sink current ISW1SI µAVC1 = 0.05V, VC2 = 0.05V, VSW1 = 1.0V– 40 — —
Source current ISW2SO mA VC1 = 0.05V, VC2 = 0.05V, VSW2 = 0V3.2 4.4 6.1
Pull-down resistance RSW2 Ω Vst = 0.35V, VSW2 = 0.3V400 500 600

Operating VSTON V1.0 — — —

—

—

—
—

Non-operating VSTOFF V— — 0.3

Quiescent current in standby state IQ (ST) µA— 0 2.0

Max. Unit Conditions

•

Measurement circuit

2

ISW1

VSW1

fSW1

VCC

Counter

VC1

0.033µF

IQ

VSTBY

8

VC2

1500pF

± 1%

± 1%

1

ISW2

VSW2

fSW2

Counter

7

3 4

STBY

OSC2

OSC1

R

SW2

Fig.1

A A

A

6 5

4

Standard ICs BA3899F

•

Application example

567

STBY

8

OSC2

OSC1

Fig. 2

RSW2

EL 16000pF R1 2k

D1

Q2

Q1

L1

100k

V

CC = 5V

ROHM: 1SS376

ROHM: 2SC4061KP

SW1 SW2 STBY

R

X

300k

V

CC

SANYO: 2SC3645T

1.5mH (TOKO: D73LC)

∗

GND N.C. C1

C1
8200pF ± 10%

2.2µF

C2
1500pF ± 10%

C2

1234

+

∗

Because of the characteristics of the EL element, continuous application of particularly high DC power supply voltage can shorten the lifetime of the
element. To avoid this, we recommend inserting a switch in the power supply line.

5

Standard ICs BA3899F

2

5

STBY

GND N.C. C1 C2

SW1

R1 4.7k

ROHM: 1SS376

D1

EL 5000pF

SW2 V

CC

VCC = 1.5V

STBY

OSC2

OSC1

R

SW2

Q1

Q2

L1

1mH

ROHM: 2SC4061KP

SANYO: 2SC3143K5

(

TOKO: 43FS) or (TDK: NL453232

)

C2
1500pF ± 10%

C1

0.033µF ± 10%

41 3

68 7

VSTBY = 1.5V
Hi: act

Fig. 3

2.2µF

+

6

Standard ICs BA3899F

•

Operation notes
(1) EL drive output
As shown in Figure 4, the EL drive output consists of
charging (rise in voltage caused by switching) and dis­charging waveforms. The switching frequency is deter­mined by f

SW2 and the charging and discharging timing

by f

SW1.

(4) Q1, Q2, and D1
The V

O (Max.) shown in Figure 4 is applied to the output

V

O, so if using any transistor other than that recom-

mended, caution is required concerning the pressure
withstand value. Also, Q2 must have characteristics
which allow it to keep pace with the switching speed of
f

SW2.

t1

tSW1 (fSW1)

V

O (Max.)

t2

Charge

Discharge

Fig.4

(2) Setting fSW1
The oscillation frequency is determined by charging
and discharging of the external capacitance of the C1
pin. The value for C1 should be set based on the fol­lowing equation.

(5) R

X (resistor for adjusting light volume)

With a configuration like that shown in Figure 5, the
volume of light can be adjusted. However, R

X should

be set so that I

X satisfies the following condition.

C1 = ×

= (3.14E – 6) ×

( + ) V

C1 ×

(V

CC = 5V)

1

11

I

1

1

f

SW1

I2
1

fSW1

Ix ( = ) < 40µA

Vx – 0.2V

Rx

If IX > 40µA, LSI dispersion, temperature fluctuation,
and other elements can cause oscillation of the C2 pin
to stop. Be sure the above condition is satisfied.

The recommended setting range for f

SW1 is 40Hz to

800Hz. However, the V

O (Max.) shown in Figure 4 is

determined by f

SW1, so caution is required concerning

the pressure withstand values of Q1, Q2, and D1.

(3) f

SW2

fSW2 is the switching pressure rise frequency, and is
determined by the external capacitance of the C2 pin.
This value (1500pF) is determined by the inductance
value and the Q2 transistor capability. When changing
this value, the drive capability of Q2 must be taken into
consideration in order to avoid the possibility of mal­function.

4

C2

1500pF

Vx

Rx

Ix

Fig.5

7

Standard ICs BA3899F

•

Electrical characteristic curves

0

012345678910

1

2

3

4

5

6

7

C1 = 0.033µF
C2 = 1500pF
V

ST = 5V

Rx = ∞

8

9

10

QUIESCENT CURRENT: ICC (mA)

75°C

– 25°C

25°C

INPUT VOLTAGE: V

CC (V)

Fig. 6 Supply current (when used
as stand-alone unit) vs.
power supply voltage

10k

1k

100

023154678

OSCILLATION FREQUENCY: fSW (Hz)

C1 = 0.033µF
C2 = 1500pF
Rx = ∞

75°C

fSW1

fSW2

– 25°C

25°C

75°C

– 25°C

25°C

INPUT VOLTAGE: VCC (V)

Fig. 7 Oscillation frequency of C1
and C2 pins vs. power supply
voltage

SW1 SOURCE CURRENT: ISWISO (µA)

0

012345678910

50

100

150

200

250

VC1 = 1.0V
V

SW1 = 0V

25°C

– 25°C

75°C

INPUT VOLTAGE: V

CC (V)

Fig. 8 SW1 sink current vs.

power supply voltage

SW1 SINK CURRENT: ISW1SI (%)

INPUT VOLTAGE: VCC (V)

0

012345678910

10

2.0

3.0

1.0

VC1 = 0V
V

SW1 = 1.0V

V

ST = 5V

25°C

– 25°C

75°C

Fig. 9 SW1 source current vs.

power supply voltage

0

012345678910

1

2

3

4

5

6

7

V

C1 = 1.0V

V

SW1 = 0V

V

ST = 5V

8

9

10

SW2 SOURCE CURRENT: ISW2SO (mA)

INPUT VOLTAGE: VCC (V)

75°C

– 25°C

25°C

Fig. 10 SW2 source current vs.

power supply voltage

0

012345678910

100

200

300

400

500

600

700

VCC = 5V
V

SW2 = 0.2V

V

ST = 0V

800

900

1000

SW2 PULL-DOWN RESISTANCE: RSW2 (Ω)

INPUT VOLTAGE: VCC (V)

75°C

– 25°C

25°C

Fig. 11 SW2 pull-down resistance vs.
power supply voltage

8

Standard ICs BA3899F

•

External dimensions (Units: mm)

SOP8

0.4 ± 0.11.27

0.15

0.3Min.

0.15 ± 0.1

0.11

6.2 ± 0.3

4.4 ± 0.2

5.0 ± 0.2

85

41

1.5 ± 0.1