Datasheet SP4424CN, SP4424CU, SP4424CX, SP4424NEB Datasheet (Sipex Corporation)

®

SP4424

Electroluminescent Lamp Driver

Dual Oscillators

■ DC to AC Inverter for EL Backlit
Display Panels

■ 2.2V - 5.0V Battery Operation

■ Dual Oscillator Operation for

Application Flexibility

■ Low Current Standby Mode

APPLICATIONS

■ PDAs

■ Cellular Phones

■ Remote Controls

■ Hand Held Computers

DESCRIPTION

The SP4424 is a high voltage output DC-AC converter that can operate from a single battery
supply voltage as low as 2.2V. The SP4424 is capable of supplying up to 220 VPP signals,
making it ideal for driving electroluminescent lamps. The device features 5µA (maximum)
standby current, for use in low power portable products. An inductor is used to generate high
voltage pulses, and two external capacitors are used to select the inductor and the lamp
oscillator frequencies. The SP4424 is offered in both an 8-pin narrow SOIC and 8-pin micro
SOIC packages. For delivery in die form, please consult the factory.

C

COIL

V

SS

COIL

1
2

3

SP4424

4

SP4424 Block Diagram

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

1

8
7

6
5

C

LAMP

HON
V

DD

EL2EL1

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation sections
of the specifications below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect reliability.

VDD.....................................................................................................7.0

V Input Voltages/Currents

HON (pin1)...............................................................-0.5V to (VDD+0.5V)

COIL (pin3)....................................................................................60mA

Lamp Outputs............................................................................230V

Storage Temperature...................................................-65˚C to +150˚C

SPECIFICATIONS

(T= 25°C; V

DD =3.0V; Lamp Load = 55nF; Coil = 5mH at 18 Ohms; Coil OSC = 220pF, Lamp OSC = 1500pF unless otherwise noted)

PP

Power Dissipation Per Package

8-pin NSOIC (derate 6.14mW

o

C above +70oC)..................500mW

8-pin µSOIC (derate 4.85mWoC above +70oC)...................390mW

The information furnished herein by Sipex has been carefully reviewed
for accuracy and reliability. Its application or use, however, is solely the
responsibility of the user. No responsibility for the use of this information
is assumed by Sipex, and this information shall not explicitly or implicitly
become part of the terms and conditions of any subsequent sales
agreement with Sipex. Specifications are subject to change without
prior notice. By the sale or transfer of this information, Sipex assumes
no responsibility for any infringement of patents or other rights of third
parties which may result from its use. No license or other proprietary
rights are granted by implication or otherwise under any patent or
patent rights of Sipex Corporation.

RETEMARAP.NIM.PYT.XAMSTINUSNOITIDNOC

V,egatloVylppuS

DD

I+

,tnerruCylppuSI

LIOC

DD

V,egatloVlioC

LIOC

V,egatloVtupnINOH

NOH

ffoLE:WOL

noLE:HGIH

noLE,tnerruCNOH01

I=

I+

I,tnerruCnwodtuhS

DS

LIOC

DD

2.20.30.5V
5305AmV

VDD..0.5

52.0-

52.0-

0

V

V

DD

DD

V

DD

V52.0

52.0+

V

V

µA

15

µA

V3=

NOH

V

V0=

NOH

V=

V,nwodlluplanretni

V3=

NOH

DD

EVIRDROTCUDNI

f,ycneuqerFlioC

LIOC

346 zHk

elcyCytuDlioC57%

I,tnerruClioCkaeP

LIOC-KP

06Am.ngisedybdeetnarauG

TUPTUOPMALLE

f,ycneuqerFpmaLLE

PMAL

051
001

egatloVtuptuOkaePotkaeP06

001

002052

004

09

031

06

021

061

zH

V

PP

O

T

52+=

C

BMA

O

T

04-=

BMA

T

52+=

BMA

52+=

T

BMA

O

T

04-=

BMA

T

52+=

BMA

O

58+otC

C

O

V,C

V2.2=

DD

O

V,C

V0.3=

DD

O

58+otC

V,C

V0.3=

O

V,C

DD

V0.5=

DD

This data sheet specifies environmental parameters, final test conditions and limits as well suggested operating conditions.
For applications which require performance beyond the specified conditions and or limits please consult the factory.

Bonding Diagram:

Coil

V

DD

EL 2
EL1

HON

C

C

LAMP

COIL

SP4424

663A

V

SS

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

PAD X Y
EL1 586.0 187.0
EL2 586.0 -143.0
COIL 586.0 -376.0

V

SS

HON -562.5 397.0
CAP2 -565.0 -118.0
CAP1 -562.5 114.5

V

DD

NOTES:

1. Dimensions are in Microns unless otherwise noted.

2. Bonding pads are 125x125 typical.

3. Outside dimensions are maximum, including scribe area.

4. Die thickness is 10 mils +/- 1.

5. Pad center coordinates are relative to die center.

6. Die size 1498 x 1168 ( 59 x 46 mils).

-80.0 -417.0

588.0 417.0

2

PIN DESCRIPTION

1

SP4424CN

2
3
4

Pin 1 – C
pin 1 to set coil frequency.

- Connect Capacitor from VSS to

COIL

8
7
6
5

Pin 2 – VSS- Power supply common, connect to
ground.

Pin 3 – Coil- Coil input, connect coil from
V

BATTERY

to pin 3.

Pin 4 – EL1- Lamp driver output 1, connect to
EL lamp.

Pin 5 – EL2- Lamp driver output 2, connect to
EL lamp.

Pin 6 – VDD- Power supply for driver, connect to
system VDD.

Pin 7 – HON- Enable for driver operation,
high = active; low = inactive.

Pin 8 – C
pin 8 to set lamp frequency.

- connect Capacitor from VSS to

LAMP

THEORY OF OPERATION

The SP4424 is made up of four basic circuit
elements: two precision oscillators, a coil, and the
EL driver IC. The oscillators set the coil and lamp
frequencies independently. This allows for the
selective setting of the coil / lamp frequency ratio.
The coil frequency can be selected for maximum
energy transfer per cycle for a given coil value.
The coil oscillator is designed to operate at 75%
duty cycle and the lamp oscillator is designed for
50% DC, for minimum DC offset across the EL
lamp.

An external capacitor connected between pin 8
and VSS allows the user to vary the lamp oscillator
frequency from approximately 75Hz (4700 pf) to
350Hz (450 pf). Likewise, an external capacitor
connected between pin 1 and V
to vary the coil oscillator frequency from

allows the user

SS

approximately 5kHz (390 pf) to 50kHz (22 pf).
The graphs on page 7 show the relationship between
oscillators (L
capacitor values.

and C

OSC

) and their respective

OSC

The coil is an external component connected from
V

BATTERY

in the coil according to the equation EL=1/2LI2,

to pin 3 of the SP4424. Energy is stored

where I is the peak current flowing in the inductor.
The current in the inductor is time dependent and
is set by the "ON" time of the coil switch: I=(VL/
L)tON, where VL is the voltage across the inductor.
At the moment the switch closes, the current in the
inductor is zero and the entire supply voltage
(minus the V
The current in the inductor will then ramp up at a

of the switch) is across the inductor.

SAT

220pF

V

=3V

IN

5mH/18Ω

SP4424 Typical Application

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

+

–

C

V

Coil

EL1

COIL

SS

SP4424

C

LAMP

HON

V

DD

EL2

1500pF

HON=VDD=ON
HON=0V=OFF

0.1µF Low ESR
Decoupling
Capacitor

EL Lamp

1.6 sq.in.

4.5nF

3Ftl

3

linear rate. As the current in the inductor builds up,
the voltage across the inductor will decrease due to
the resistance of the coil and the "ON" resistance
of the switch: VL=V
voltage across the inductor is decreasing, the current

BATTERY

-IRL-V

. Since the

SAT

ramp-rate also decreases which reduces the current
in the coil at the end of tON the energy stored in the
inductor per coil cycle and therefore the light
output. The other important issue is that maximum
current (saturation current) in the coil is set by the
design and manufacturer of the coil. If the
parameters of the application such as V
RL or ton cause the current in the coil to increase
beyond its rated I
generated and the power efficiency will decrease

, excessive heat will be

SAT

BATTERY

, L,

with no additional light output. The majority of the
current goes through the coil and typically less
than 3 mA is required for VDD of the SP4424. V
can range from 2.2V to 5V; it is not necessary that
VDD=V
source (3.3V) can be directly connected to the coil,

. For example, an unregulated voltage

BATTERY

DD

while a regulated voltage source (2.85V) can be
connected to the IC VDD pin.

Coil performance is also a function of the core
material and wire used -- performance variances
may be noticeable from different coil suppliers.
The Sipex SP4424 is tested using a 5mH/18Ω coil
from Hitachi Metals. For suggested coil sources
see page 9.

magnetic field is generated in the coil. During
the low part of f
switched open, the field collapses and the voltage

, the ground connection is

COIL

generated in the inductor is directed to the high
voltage H-bridge switches. f
charge pulses as possible in 1 Lamp Cycle.{Number of
Coil pulses in 1 lamp cycle =}

will send as many

COIL

1

Coil Freq.

x

Lamp Freq

2

}

(see figure 2 on page 6). Each pulse increases the
voltage drop across the lamp in discrete steps. As
the voltage potential approaches its maximum, the
steps become smaller (see figure 1 on page 6).

The H-bridge consists of two SCR structures that
act as high voltage switches. These two switches
control the polarity of the lamp (capacitor) as it is
charged. The SCR switches are controlled by the
f

signal which is the oscillator frequency

LAMP

divided by 2.

When the energy from the coil is released, a high
voltage spike is created triggering the SCR
switches. The direction of current flow is
determined by which SCR is enabled. One full
cycle of the H-bridge will create a number of
voltage steps from ground to 65V (typical) on pins
4 and 5 which are 180 degrees out of phase (see
figure 3 on page 6). A differential view of the
outputs is shown in figure 4 on page 6.

The f
the end of the coil at pin 3 to ground or to open
circuit. The f
During the time when the f
coil is connected from V

SP4424 Test Circuit

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

signal controls a switch that connects

COIL

signal is a 75% duty cycle signal.

COIL

V

=3V

IN

+

5mH/18Ω

–

signal is high, the

COIL

BATTERY

to ground and a

220pF

C

V

Coil

EL1

COIL

SS

SP4424

C

LAMP

HON

V

DD

EL2

1500pF

HON=VDD=ON
HON=0V=OFF

0.1µF Low ESR
Decoupling
Capacitor

100Ω

55nF

4

CIRCUIT LAYOUT CONSIDERATIONS:

The SP4424 IC incorporates two independent
asynchronous oscillators, one of which supplies
the signal for switching of the coil transistor which
generates the coil charge pulses and the other
supplies the clock signal to switch the high voltage
H-bridge output circuit.

It is necessary to keep all high voltage signals
away from these oscillator clock signals as much
as possible as crosstalk between the two signals
can cause distortion in the EL drive signal which
can result in either low light output or blinking of
the EL lamp. It is always recommended that a low
ESR decoupling capacitor (0.1 µF or >) be used
between the VDD (pin 6) and ground (pin 2). The
VSS (gnd) pin should in turn be connected to the
system ground plane. If it is connected via a
circuit trace, this trace should be as short and as
wide as possible.

Electroluminescent Technology

What is electroluminescence?

An EL lamp is basically a strip of plastic that is
coated with a phosphorous material which emits
light (fluoresces) when a high voltage (>40V)
which was first applied across it, is removed. Long
periods of DC voltages applied to the material
tend to breakdown the material and reduce its
lifetime. With these considerations in mind, the
ideal signal to drive an EL lamp is a high voltage
sine wave. Traditional approaches to achieving
this type of waveform included discrete circuits
incorporating a transformer, transistors, and several
resistors and capacitors. This approach is large,
power hungry, expensive and bulky, and would be
difficult to implemented in most hand held
equipment.

Sipex now offers low power single chip driver
circuits specifically designed to drive small to
medium sized electroluminescent panels. All that
is required is one external inductor and capacitor.

Electroluminescent backlighting is ideal for use
with LCD displays, keypads, or other backlit
readouts. Its primary use is to illuminate displays
in dim to dark conditions for momentary periods
of time. EL lamps typically consume less current
than LEDs or bulbs making them ideal for battery
powered products. Also, EL lamps are able to
evenly light an area without creating "hot spots" in
the display.

The amount of light emitted is a function of the
voltage level applied to the lamp, the frequency at
which it is applied and the lamp size and method of
construction . There are many variables which can
be optimized for specific applications. Sipex
supplies custom characterization data to aid the
designer in selecting the optimum circuit
configuration.

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

5

EL1 output; charge steps per half cycle based on # of coil pulses per half cycle.

Figure 1. EL output voltage in discrete steps at EL1 output

V

=65V (typical)

PEAK

Number of coil pulses in lamp cycle = ; 70% duty cycle.

coil

lamp freq. (2)

Figure 2. Voltage pulses released from the coil to the EL driver circuitry

Figure 3. EL voltage waveforms from the EL1 and EL2 outputs

-EL2 Output

EL1 Output

EL1 Output

-EL2 Output

VPP=160V
(typical)

Differential Representation (EL1-EL2).

Figure 4. EL differential output waveform of the EL1 and EL2 outputs

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

6

The following performance curves are intended to give the designer a relative scale from which to optimize
specific applications. Absolute measurements may vary depending upon the brand of components chosen.

20.0

15.0

10.0

5.0

Frequency (KHz)

0.0
50

68

75

Coil Osc Cap (pF)

100

Coil Frequency vs. Coil Osc Cap Value

6
5
4
3
2
1

Light Output (FtL)

0

50

68

75

Coil Cap (pF)

100

Coil Cap vs. Light Output

16
14
12
10

8
6
4
2

Light Output (FtL)

0

1

1.5

2

Lamp Size (Sq. in)

2.3

3

Lamp Size vs. Light Output

122

122

3.4

240
230
220

(VAC)

210

PP

200

OUT

E

190
180

16.0

13.6
Coil Frequency (KHz)

Coil Frequency vs. E

30
25
20
15

(mAz)

10

TOTAL

I

5
0

50

68

Coil Osc Cap (pF)

vs. Coil Osc Cap

I

TOTAL

600
500
400
300
200

Frequency (Hz)

100

0

580

680

Lamp Osc Cap (pF)

11.7

OUT PP

75

820

1000

9.4

100

1400

Lamp Frequency vs. Lamp Osc Cap Value

7.4

122

1800

240
230
220
210

(VAC)

PP

200

OUT

E

190
180

580

680

820

Lamp Osc Cap (nF)

Lamp Osc Cap vs. E

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

1000

OUT PP

1400

1800

250
200
150

(VAC)

100

OUT PP

E

50

0

1

Lamp Size vs. E

1.5

2

Lamp Size (sq. in)

OUT PP

2.3

3.4

3

7

The following performance curves are intended to give the designer a relative scale from which to optimize
specific applications. Absolute measurements may vary depending upon the brand of components chosen.

140
120

100

80
60
40

Peak to Peak

Voltage (Volts)

20

0

-40

0

25

Temperature (oC)

70

Peak to Peak Voltage vs. Temperature
C

=220pF; C

COIL

40
35
30
25

20

15
10

Total Current (mA)

5
0

-40

=1500pF; Load=55nF

LAMP

0

25

Temperature (oC)

70

Total Current vs. Temperature
C

=220pF; C

COIL

=1500pF; Load=55nF

LAMP

350

300
250
200

3.0V

2.2V

85

150
100

50

Lamp Frequency (Hz)

0

-40

0

25

Temperature (oC)

70

3.0V

2.2V

85

Lamp Frequency vs. Temperature

=220pF; C

C

COIL

8
7

6
5

3.0V

2.2V

85

4
3
2
1

Coil Frequency (Khz)

0

-40

=1500pF; Load=55nF

LAMP

0

25

Temperature (oC)

3.0V

2.2V

70

85

Coil Frequency vs. Temperature
C

=220pF; C

COIL

=1500pF; Load=55nF

LAMP

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

8

The coil part numbers presented in this data sheet have been qualified as being suitable for the SP4422A product.
Contact Sipex for applications assistance in choosing coil values not listed in this data sheet.

CTC Coils LTD Hong Kong
Ph: 85-2695-4889

25 ± 2.0

Fax: [phone]
Mark Technologies:

North American Stocking
distributor for Sankyo and CTC
Ph: 905-891-0165
Fax: [phone]

Model Numbers: CH5070AS-203K-006 (20mH, 65Ω)
Sipex Number: S51208-M-1021-Sipex

HITACHI METALS Ltd. Japan
Ph: 3-3284-4936
Fax: [phone]

HITACHI METALS Singapore
Ph: 65-222-3077
Fax: [phone]

Part Numbers:
MD735L902B (9mH
MD735L502A (5mH + 20% 19.8Ω)

Toko Inc. Japan
Ph: 03-3727-1161
Fax: [phone]

Toko America Inc. USA
Ph: 847-297-0070
Fax: [phone]

Part Numbers:
667MA-472N (4.7mH, 13Ω)

muRata USA
Ph: 770-436-1300
Fax: [phone]

muRata Europe
Ph: 49-9116-6870
Fax: [phone]

+ 20% 41Ω)

Toko Inc. Singapore
Ph: 255-4000
Fax: [phone]

Toko Germany
Ph: 49-7156-96-060
Fax: [phone]

Toko U.K.
Ph: 1753-854057-9
Fax: [phone]

muRata Taiwan
Ph: 88-6429-1415-1
Fax: [phone]

muRata Singapore
Ph: 65-758-4233
Fax: [phone]

HITACHI METALS Hong Kong
Ph: 852-2724-4183
Fax: [phone]

HITACHI METALS Chicago, IL
Ph: 847-364-7200
Fax: [phone]

2.5

6.5 Max

6.8
±0.3

Toko Korea
Ph: 0551-50-5500
Fax: [phone]

Toko France
Ph: 01-4557-4465
Fax: [phone]

Toko Hong Kong
Ph: 2342-8131
Fax: [phone]

muRata Hong Kong
Ph: 85-2237-6389-8
Fax: [phone]

Part Numbers:
LQN6C472M04 (4.7mH, 35Ω)
LQN6C103M04 (10mH, 80Ω)

4.4

9.0 Max

3.3
±0.3

4.4 Max

(All dimensions in mm)

6.0 ±0.3

(All Dimensions in mm)

(All Dimensions in mm)

5.7 ±0.3

(All Dimensions in mm)

7.0 ±0.5

2.75 Max

5.0 ±0.35.0 ±0.3

4.7 ±0.3

Coilcraft USA
Ph: 847-639-6400
Fax: [phone]

Coilcraft Europe
Ph: 44-01236-730595
Fax: [phone]

Part Numbers:
DS1608C-106 (10mH, 32Ω)

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

Coilcraft Taiwan
Ph: 886-2-264-3646
Fax: [phone]

Coilcraft Singapore
Ph: 65-296-6933
Fax: [phone] #382

Coilcraft Hong Kong
Ph: 852-770-9428
Fax: [phone]

.260

MAX

6,60

.175

MAX

4,45

Magnetically Shielded

(All Dimensions in mm)

.115

MAX

2,92

9

EL polarizers/transflector
manufacturers

Nitto Denko
San Jose, CA
Phone: [phone]

Astra Products
Baldwin, NJ
Phone: [phone]
Fax: [phone]

EL Lamp manufacturers

Metro Mark/Leading Edge
Minnetonka, MN
Phone: [phone]
Phone: [phone]

Midori Mark Ltd.
1-5 Komagata 2-Chome
Taita-Ku 111-0043 Japan
Phone: [phone]

Luminescent Systems Inc. (LSI)
Lebanon, NH
Phone: [phone]
Fax: [phone]

NEC Corporation
Tokyo, Japan
Phone: [phone]
Fax: [phone]

Seiko Precision
Tokyo, Japan
Phone: [phone]
Fax: .) 5610-7177

Gunze Electronics
2113 Wells Branch Parkway
Austin, TX 78728
Phone: [phone]
Fax: [phone]

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

10

8-pin NSOIC

All package dimensions in inches

8-pin µSOIC

0.189/0.197

SP4424CN

1

0.228/0.2440.150/0.157

0.014/0.019

0.050 BSC

0.053/0.069

0.020

95 SP4424CN per tube, no minimum quantity

0.0965
±0.003

0.020

0.0256
BSC

SP4424CU

1

2

0.116

±0.004

0.013
±0.005

0.118

±0.002

0.118

±0.002

0.004

±0.002

0.034

±0.002

0.040
±0.002

0.012

±0.003

0.16

±0.003

R .003

12.0˚

50 SP4424CU per tube

12.0˚
±4˚

0.008
0˚ - 6˚

0.006

±0.006

0.006

±0.006

0.01

0.037
Ref

0.0215
±0.006

0.116

±0.004

0.118

±0.004

±4˚

3.0˚
±3˚

P

W

NSOIC-8 13" reels: P=8mm, W=12mm

µSOIC-8 13" reels: P=8mm, W=12mm

Pkg. Minimum qty per reel Standard qty per reel Maximum qty per reel

CN 500 2500 3000
CU 500 2500 3000

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

11

ORDERING INFORMATION

Model Operating Temperature Range Package Type

SP4424CN . ............................................-40˚C to +85˚C .........................................8-Pin NSOIC

SP4424CU . ............................................ -40˚C to +85˚C ......................................... 8-Pin µSOIC

SP4424CX .............................................. -40˚C to +85˚C ........................................................ Die

SP4424NEB.....................................................N/A ...............................NSOIC Evaluation Board

SP4424UEB.....................................................N/A ............................... µSOIC Evaluation Board

Please consult the factory for pricing and availability on a Tape-On-Reel option.

Corporation

SIGNAL PROCESSING EXCELLENCE

Sipex Corporation
Headquarters and

Sales Office

22 Linnell Circle
Billerica, MA 01821
TEL: [phone]
FAX: [phone]
e-mail: [e-mail]

Sales Office

233 South Hillview Drive
Milpitas, CA 95035
TEL: [phone]
FAX: [phone]

Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.

SP4424DS/16 SP4424 Electroluminescent Lamp Driver © Copyright 2000 Sipex Corporation

12