1
General Description:
The Durel
D340B is part of a family of highly integrated EL
drivers based on Durel's patented three-port (3P) topology, which
offers built-in EMI shielding. This low-cost, regulated device is
well suited for backlighting timepieces and small liquid crystal
displays for portable electronic applications.
Small System Footprint
Timepieces
Regulated AC output voltage
Pagers
Low Standby Current
Calculators
High Efficiency
Handsets
Features
Applications
Standard Test Circuit
nA
E' = V+
mA
E' = GND
Vpp
E' = GND
Hz
E' = GND
Parameter
Symbol
Minimum
Typical
Maximum
Unit
Conditions
(Using Standard Test Circuit at Ta=25 C unless otherwise specified.)
Lamp Driver Specifications:
Standby Current
5
1000
Supply Current
I
12
20
Output Voltage
Vout
110
144
160
Lamp Frequency
LF
100
140
200
Data Sheet
D340B
Electroluminescent
Lamp Driver IC
MSOP-8
OFF
LOAD B
V+
E'
GND
N/C
L+
VOUT
L-
N/C
1
2
4
5
6
7
8
3
3.3 V
4.7 uF
4.7 mH
(59 Ohm DCR)
(3.0 V)
ON
D340B
D341B
2
Typical Output Waveform
Load A*
Physical Data:
Absolute Maximum Ratings:
* Load B approximates a 5in
2
(32 cm
2
) EL lamp.
Note: The above are stress ratings only. Functional operation of the device at these ratings or any other above
those indicated in the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
Parameter
Symbol
Minimum
Maximum
Unit
Comments
100
22 nF
10k
47 nF
Supply voltage
Operating Range
V+
1.0
7.0
V
E = GND
Withstand Range
- 0.5
10.0
E = V+
Enable Voltage
E
- 0.5
(V+) +0.5
V
Output Voltage
V
OUT
160
Vpp
Peak-to-Peak Voltage
Operating Temperature
T
a
- 40
70
C
Storage Temperature
T
s
- 40
150
C
1
2
3
4
5
6
7
8
PIN # NAME
FUNCTION
Note: Please consult factory for bare die dimensions and bond
pad locations.
1
V+
DC power supply input
2
E'
System enable; Power Down Control
3
GND
System ground connection
4
N/C
No connection
5
N/C
No connection
6
L-
Negative input to inductor
7
V
OUT
High voltage AC output to lamp
8
L+
Positive input to inductor
3
Typical Performance Characteristics Using Standard Test Circuit
Output Frequency vs. DC Supply
Voltage
0
50
100
150
200
250
300
350
400
1
2
3
4
5
6
7
DC Input Voltage
Output Frequency vs. Ambient
Temperature
0
50
100
150
200
250
300
350
400
-40
-20
0
20
40
60
80
Temperature ( C)
Output Voltage vs. DC Supply Voltage
0
40
80
120
160
200
1
2
3
4
5
6
7
DC Input Voltage
Output Voltage (Vpp)
Output Voltage vs. Ambient
Temperature
0
40
80
120
160
200
-40
-20
0
20
40
60
80
Temperature ( C)
Output Voltage (Vpp)
Supply Current vs. DC Supply Voltage
0
5
10
15
20
25
30
1
2
3
4
5
6
7
DC Input Voltage
Supply Current vs. Ambient
Temperature
0
5
10
15
20
25
30
-40
-20
0
20
40
60
80
Temperature ( C)
4
Theory of Operation
Electroluminescent (EL) lamps are essentially capacitors with one transparent electrode and a special phosphor material
in the dielectric. When a strong AC voltage is applied across the EL lamp electrodes, the phosphor glows. The
required AC voltage is typically not present in most systems and must be generated from a low voltage DC source.
Thus, Durel developed its patented Three-Port (3P) switch-mode inverter circuit to convert the available DC supply
to an optimal drive signal for high brightness and low-noise EL lamp applications. The Durel 3P topology offers the
simplicity of a single DC input, single AC output, and a shared common ground that provides an integrated EMI
shielding.
The D340B drives the EL lamp by repeatedly pumping charge through an external inductor with current from a DC
source and discharging into the capacitance of the EL lamp load. With each high frequency (HF) cycle the voltage on
the lamp is increased. When the voltage on the lamp reaches the set voltage on the comparator, the voltage on the lamp
is discharged to ground and the polarity of the inductive charging is reversed. By this means, an alternating positive
and negative voltage is developed at the single output lead of the device to one of the electrodes of the EL lamp. The
other lamp electrode is commonly connected to a ground plane, which can then be considered as electrical shielding
for any underlying circuitry on the application.
The EL driving system is divided into several parts: on-chip logic and control, on-chip high voltage output circuitry, and
off-chip components. The on-chip logic controls the inductor switching frequency (HF) and change in lamp charging
polarity at a frequency (LF) that is dependent on the lamp load size and DC voltage source. These signals are combined
and buffered to regulate the high voltage output circuitry. The output circuitry handles the power through the inductor
and delivers the high voltage to the lamp. The selection of off-chip components provides a degree of flexibility to
accommodate various lamp sizes, system voltages, and brightness levels. Since a key objective for EL driver systems
is to save space and cost, required off-chip components were kept to a minimum.
Durel provides a D340B Designer's Kit, which includes a printed circuit evaluation board intended to aid you in
developing an EL lamp driver configuration using the D340B that meets your requirements. A section on designing
with the D340B is included in this datasheet to serve as a guide to help you select the appropriate external components
to complete your D340B EL driver system.
Typical D340B configurations for driving EL lamps in various applications are shown on the following page. The
expected system outputs, such as lamp luminance, lamp output frequency and voltage and average supply current
draw, for the various sample configurations are also shown with each respective figure.
Block Diagram of the Driver Circuitry
5
1.5V Analog Watch
Typical Output
Luminance= 2.9 fL (10 cd/m
2
)
Lamp Frequency = 214 Hz
Supply Current = 10 mA
Vout = 144 Vpp
Load = 645 mm
2
(1 in
2
) Durel 3 Green EL
Typical D340B EL Driver Configurations
OFF
V+
E'
GND
N/C
L+
VOUT
L-
N/C
1
2
4
5
6
7
8
3
4.7 uF
(3.0 V)
ON
D340B
1.5 V
2.2 mH
Murata
LQS33C
1 in
2
EL Lamp
OFF
V+
E'
GND
N/C
L+
VOUT
L-
N/C
1
2
4
5
6
7
8
3
4.7 uF
(3.0 V)
ON
D340B
6.0 mH
Hitachi Metals
#MD520L-602A
3.0 V
1 in
2
EL Lamp
3.0 V Pager or Digital Watch
Typical Output
Luminance = 4.7 fL (16 cd/m
2
)
Lamp Frequency = 600 Hz
Supply Current = 11 mA
Vout = 140 Vpp
Load = 645 mm
2
(1 in
2
) Durel 3 Blue-Green EL
OFF
V+
E'
GND
N/C
L+
VOUT
L-
N/C
1
2
4
5
6
7
8
3
4.7 uF
(3.0 V)
ON
D340B
6.0 V
10 mH
Coilcraft
DT1608C
4 in
2
EL Lamp
6.0 V Remote Control
Typical Output
Luminance = 5.8 fL (20 cd/m
2
)
Lamp Frequency = 530 Hz
Supply Current = 16 mA
Vout = 145 Vpp
Load = 2580 mm
2
(4 in
2
)
Durel 3 Green EL
The D340B may be used to drive two or more EL lamps or EL lamp segments independently. An external switching
circuit can be used to turn each lamp segment on or off. A high signal at the E input for the corresponding EL lamp will
power the segment when the IC is enabled. In this example, Segment 1 is always on when the Durel D340B is enabled.
Otherwise, always make sure that at least one segment is switched on when the driver IC is activated.
I. Driving Multi-Segment Lamps
A low logic signal at the E' pin will enable the D340B. Adding a transistor and two resistors will allow the D340B to
be enabled with a high voltage signal.
D340B Design Ideas
II. Enabling the D340B with a High Logic Signal
III. Two-Level Dimming
Toggle switching between two different EL lamp brightness levels may be achieved with the following
circuit. When DIM is low, the external pnp transistor is saturated and the EL lamp runs at full brightness.
When DIM is high, the external pnp turns off and the 47W resistor reduces the voltage at (V+) and dims the
EL lamp.
7
IV. Automatic Turn-Off After Short Time Delay
It is sometimes desirable for the EL lamp to turn off automatically after a few seconds of operation. Typically, a
mechanical switch pulls E' low to initially turn on the device. When the switch is released, Cdelay keeps the D340B
operating for a short period before turning off. The following table shows typical delay on-times.
C delay (uF)
1.5V
3.0V
5
1.8 sec
2.4 sec
7
2.3 sec
3.1 sec
10
5.6 sec
7.8 sec
15
5.9 sec
9.0 sec
20
7.7 sec
11.2 sec
Vbat
V+
E'
GND
N/C
L+
VOUT
L-
N/C
1
2
4
5
6
7
8
3
D340B
EL Lamp
EL Lamp
1.0uF
Vbat
5.6 mH
Cdelay
1MOhm
V. Automatic Turn-Off After Long Time Delay
Longer on-times can be achieved with the addition of an external transistor. Typically, a mechanical switch
pulls E' low to initially turn on the device. When the switch is released, Cdelay keeps the D340B operating
for a period before turning off. The following table shows typical delay on-times using the following circuit
with smaller capacitor values.
8
C delay (uF)
1.5V
3.0V
1
8 sec
11 sec
2
16 sec
21 sec
3
25 sec
31 sec
Vbat
The DUREL name and logo are registered trademarks of DUREL CORPORATION.
This information is not intended to and does not create any warranties, express or implied, including any warranty of merchantability or fitness for a
particular purpose. The relative merits of materials for a specific application should be determined by your evaluation.
The EL driver circuits herein are covered by US patent #5,313,141. Corresponding foreign patents are issued and pending.
A
0.94
0.037
1.02
0.040
1.09
0.043
B
0.05
0.002
0.10
0.004
0.15
0.006
C
0.20
0.008
0.33
0.013
0.46
0.018
D
0.41
0.016
0.53
0.021
0.65
0.026
E
0.13
0.005
0.18
0.007
0.23
0.009
F
2.84
0.112
3.00
0.118
3.15
0.124
G
0.43
0.017
0.65
0.026
0.83
0.033
H
4.70
0.185
4.90
0.193
5.11
0.201
I
2.84
0.112
3.00
0.118
3.25
0.128
Description
mm.
in.
mm.
in.
mm.
in.
MSOP-8
Min.
Typical
Max.
The D340B IC is available as bare die in probed wafer form or in die tray, and in standard MSOP-8 plastic
package in tape and reel. A Durel D340B Designer's Kit (1DDD340BB-K01) provides a vehicle for evalu-
ating and identifying the optimum component values for any particular application using D340B. Durel
engineers also provide full support to customers, including specialized circuit optimization and application
retrofits.
MSOPs in Tape and Reel:
1DDD340BB-M02
RECOMMENDED PAD LAYOUT
DUREL Corporation
2225 W. Chandler Blvd.
Chandler, AZ 85224-6155
Tel: (480) 917-6000
FAX: (480) 917-6049
Website: http://www.durel.com
1998, 2001, 2002 Durel Corporation
Printed in U.S.A.
LIT-I9011 Rev. A06
ISO 9001 Certified
Ordering Information
MSOPs are marked with part number (340B) and 3-digit wafer lot
code. Bottom of marking is on the Pin 1 side.
Embossed tape on 360 mm diameter reel per EIA-481-2.
2500 units per reel. Quantity marked on reel label.
e
c
a
b
d
f
mm.
in.
mm.
in.
mm.
in.
Min.
Typical
Max.
a
0.60
0.0236
0.6
0.0256
0.70
0.0276
b
1.90
0.0748
1.9
0.0768
2.00
0.0788
c
3.3
0.130
3.45
0.136
d
0.89
0.035
0.9
0.038
1.05
0.041
e
5.26
0.207
5.41
0.213
f
0.41
0.016
0.4
0.018
0.51
0.020
MSOP-8 PAD LAYOUT
Tape Orientation
F
H
I
A
B
G
C
D
E
PDF 
ZIP