19-0886; Rev 0; 8/07
High-Voltage, ±15kV ESD-Protected
Electroluminescent Lamp Driver
General Description
The MAX4990E high-voltage DC-AC converter is ideal
for driving electroluminescent (EL) lamps. The
MAX4990E features a wide +2.4V to +5.5V input range
that allows the device to accept a wide variety of
voltage sources such as single-cell lithium-ion (Li+)
batteries and higher voltage battery chargers. The lamp
outputs of the device generate up to 250V peak-to-
peak output voltage for maximum lamp brightness.
The MAX4990E utilizes an inductor-based boost con-
verter to generate the high voltage necessary to drive
an EL lamp. The boost-converter switching frequency is
set with the combination of an external capacitor con-
nected from SW to GND and an external resistor con-
nected from SLEW to GND.
The MAX4990E uses a high-voltage full-bridge output
stage to convert the high voltage generated by the
boost converter to an AC waveform suitable for driving
the EL panel. The EL output switching frequency is set
with the combination of an external capacitor connect-
ed from EL to GND and an external resistor connected
from SLEW to GND.
The MAX4990E uses a proprietary acoustic noise-
reduction circuit that controls the slew rate of the AC
voltage, reducing audible noise from the EL panel. The
slew rate is set with an external resistor connected from
SLEW to GND.
The MAX4990E features an EL lamp dimming control
(DIM) that allows the user to set the EL output voltage
with a PWM signal, a DC analog voltage, or a resistor
connected from the DIM input to GND. A capacitor
placed in parallel to the resistor on DIM allows the user
to program a slow turn-on/-off time that generates a soft
fade-on/fade-off effect of the EL lamp.
The MAX4990E enters a low-power shutdown mode
(100nA max) when the EN and DIM inputs are connect-
ed to GND. The MAX4990E also enters thermal shut-
down if the die temperature rises above +158°C.
The MAX4990E is available in a space-saving, 14-pin,
3mm x 3mm TDFN package and is specified over the
extended -40°C to +85°C operating temperature range.
Typical Application Circuits appear at end of data sheet.
Features
♦
ESD-Protected EL Lamp Outputs
±15kV Human Body Model
±4kV IEC 61000-4-2 Contact Discharge
±15kV IEC 61000-4-2 Air-Gap Discharge
♦
250V
P-P
(MAX) Output for Highest Brightness
♦
Wide +2.4V to +5.5V Input Voltage Range
♦
Resistor-Adjustable Slew-Rate Control for
Audible Noise Reduction
♦
Externally Driven Lamp and Switching Converter
Frequencies
♦
Capacitor-Adjustable Lamp and Switching
Converter Frequencies
♦
Low 100nA Shutdown Current
♦
DIM Input for Controlling Output Voltage Through
DC Analog Voltage, PWM, or Resistor to GND
♦
Capacitor Adjustable for Slow Turn-On/-Off
♦
Space-Saving Packages
14-Pin, 3mm x 3mm TDFN
MAX4990E
Applications
Keypad Backlighting
MP3 Players
LCD Backlighting
PDAs/Smartphones
Automotive Instrument
Clusters
Pin Configuration
N.C.
N.C.
N.C.
9
*EP
2
EN
3
DIM
4
EL
5
SW
6
V
DD
7
GND
CS
LX
8
TOP VIEW
V
A
14
13
12
V
B
11
10
MAX4990E
+
1
SLEW
TDFN-EP
*EP = EXPOSED PAD. CONNECT EP TO GND OR LEAVE UNCONNECTED.
Ordering Information
PART
MAX4990ETD+
PIN-PACKAGE
14 TDFN-EP (3mm x 3mm)
TOP
MARK
ADL
PKG
CODE
T1433-2
±15kV
PROTECTION
Yes
DIM CONTROL
Yes
SLEW-RATE
CONTROL
Yes
Note:
The device operates over the -40°C to +85°C operating
temperature range.
+Denotes
a lead-free package.
EP = Exposed paddle.
1
________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
High-Voltage, ±15kV ESD-Protected
Electroluminescent Lamp Driver
MAX4990E
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
DD
...........................................................................-0.3V to +7V
CS, LX...................................................................-0.3V to +160V
V
A
, V
B
.........................................................-0.3V to (V
CS
+ 0.3V)
EN, EL, SLEW, DIM, SW .............................-0.3V to (V
DD
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
14-Pin TDFN (derate 24.4mW/°C above +70°C) ...... 1951mW
J
A
.................................................................................41°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
= +2.4V to +5.5V, C
LAMP
= 10nF, C
CS
= 3.3nF, L
X
= 220µH (I
SAT
= 170mA, R
S
= 5.5Ω), T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at V
DD
= +3.0V and T
A
= +25°C.) (Note 1)
PARAMETER
Power-Supply Voltage
Power-Supply Current
Shutdown Supply Current
Shutdown Inductor Supply
Current
Undervoltage Lockout
UVLO Hysteresis
EL OUTPUTS (V
A
- V
B
)
V
DD
= +3V, DIM = +0.5V
Peak-to-Peak Output Voltage
V
A
- V
B
V
DD
= +3V, DIM = +1V
V
DD
= +3V, DIM = +1.3V
Pulldown Switch On-Resistance
Pullup Switch On-Resistance
R
ONPD
R
ONPU
I
LKG_NMOS
Switch Off-Leakage
I
SINK
= 1mA, V
CS
= +10V,
V
A
, V
B
< +0.6V, V
DD
= +3V
V
CS
= +125V, I
SOURCE
= 1mA
V
A
= +125V, V
B
= +125V, shutdown mode,
V
CS
= +125V
84
170
210
50
700
-1
-60
2
210
250
±15
±4
±15
kV
100
200
250
165
1500
122
230
280
500
2200
+1
µA
+60
7
290
MΩ
Hz
Ω
Ω
V
SYMBOL
V
DD
I
DD
I
SHDN
ILX
SHDN
V
LO
V
HYST
R
SLEW
= 375kΩ, slope = 30V/100µs;
f
EL
= 200Hz, V
A
- V
B
= 250V
P-P
EN = 0V, DIM = 0V, T
A
= +25°C
EN = 0V, DIM = 0V, T
A
= -40°C to +85°C
EN = 0V, DIM = 0V, LX = V
DD
, CS = V
DD
V
DD
rising
1.8
2.1
125
25
CONDITIONS
MIN
2.4
TYP
MAX
5.5
350
100
300
1500
2.3
UNITS
V
µA
nA
nA
V
mV
V = 0V, V
B
= unconnected, shutdown
I
LKG_PMOS A
mode, V
CS
= +125V
V
A
, V
B
Differential Resistor
EL Lamp Switching Frequency
ESD Protection (V
A
, V
B
Only)
V
AB_RES
f
EL
V
A
= +0.1V, V
B
= 0V, shutdown mode,
CS = unconnected
C
EL
= 872pF, R
SLEW
= 375kΩ
Human Body Model
IEC 61000-4-2 Contact Discharge
IEC 61000-4-2 Air-Gap Discharge
2
_______________________________________________________________________________________
High-Voltage, ±15kV ESD-Protected
Electroluminescent Lamp Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.4V to +5.5V, C
LAMP
= 10nF, C
CS
= 3.3nF, L
X
= 220µH (I
SAT
= 170mA, R
S
= 5.5Ω), T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at V
DD
= +3.0V and T
A
= +25°C.) (Note 1)
PARAMETER
BOOST CONVERTER
V
DD
= +3V, DIM = +0.5V forced externally
Output Peak Voltage
Boost Switching Frequency
Switch On-Resistance
LX Leakage Current
CS Input Current
CONTROL INPUT SW
Input Voltage-High Threshold
Input Voltage-Low Threshold
Input Low Current
Input High Current
CONTROL INPUT EL
Input Voltage-High Threshold
Input Voltage-Low Threshold
Input Low Current
Input High Current
CONTROL INPUT SLEW
Force Voltage
High-Voltage Output Slew Rate
CONTROL INPUT DIM
Input Logic-High Voltage
Input Logic-Low Voltage
Input Low Current
Input High Current
PWM Frequency Range
Low-Peak Detector Threshold
Low-Peak Detector Hysteresis
CONTROL INPUT EN
Input Voltage-High Threshold
Input Voltage-Low Threshold
Input Low Current
Input High Current
V
IH_EN
V
IL_EN
I
IL_EN
I
IH_EN
-1
-1
1.2
0.2
+1
+1
V
V
µA
µA
V
LPD
V
LPD_HYST
0.15
100
V
IH_DIM
V
IL_DIM
I
IL_DIM
I
IH_DIM
Output voltage (max)
Output voltage (off)
V
DIM
= 0V, R
SLEW
= 375kΩ
V
DIM
= V
DD
2.22
-1
0.2 to 1
0.35
1.3
0.15
3.0
+1
V
V
µA
µA
MHz
V
mV
V
FORCE
I
SOURCE
= 20µA
R
SLEW
= 375kΩ
0.89
0.95
30
1.04
V
V/100µs
V
IH_CEL
V
IL_CEL
I
IL_CEL
I
IH_CEL
R
SLEW
= 375kΩ
R
SLEW
= 375kΩ
R
SLEW
= 375kΩ
R
SLEW
= 375kΩ
1.08
0.22
1.2
1.2
1.32
0.39
1.87
1.87
V
V
µA
µA
V
IH_SW
V
IL_SW
I
IL_SW
I
IH_SW
R
SLEW
= 375kΩ
R
SLEW
= 375kΩ
R
SLEW
= 375kΩ, CS = +40V, EL = V
DD,
DIM = V
DD
R
SLEW
= 375kΩ, CS = +40V, EL = V
DD
,
DIM = V
DD
0.9
0.43
43
5.0
0.98
0.49
1.06
0.55
77
7.5
V
V
µA
µA
V
CS
f
SW
R
LX
I
LX
I
CS
V
DD
= +3V, DIM = +1V forced externally
V
DD
= +3V, DIM = +1.3V forced externally
C
SW
= 96pF, R
SLEW
= 375kΩ
I
SINK
= 25mA, V
DD
= +3V
V
LX
= +125V
No load, V
CS
= +125V, EN = 0V, DIM = 0V
-1
42
85
105
80
50
100
125
100
61
115
140
120
20
+1
50
kHz
Ω
µA
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4990E
_______________________________________________________________________________________
3
High-Voltage, ±15kV ESD-Protected
Electroluminescent Lamp Driver
MAX4990E
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.4V to +5.5V, C
LAMP
= 10nF, C
CS
= 3.3nF, L
X
= 220µH (I
SAT
= 170mA, R
S
= 5.5Ω), T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at V
DD
= +3.0V and T
A
= +25°C.) (Note 1)
PARAMETER
THERMAL SHUTDOWN
Thermal Shutdown
Thermal Shutdown Hysteresis
158
8
°C
°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1:
Specifications at T
A
= -40°C are guaranteed by design and not production.
Typical Operating Characteristics
(V
DD
= +3.6V, C
LAMP
= 10nF, C
CS
= 3.3nF, L
X
= 220µH (I
SAT
= 170mA, R
S
= 5.5Ω), R
SLEW
= 390kΩ, DIM = V
DD
, C
SW
= 100pF,
C
EL
= 1.2nF, T
A
= +25°C, unless otherwise noted.)
TOTAL INPUT CURRENT
vs. SUPPLY VOLTAGE
MAX4990E toc01
TOTAL INPUT CURRENT
vs. TEMPERATURE
MAX4990E toc02
TOTAL INPUT CURRENT AND
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. BOOST CONVERTER FREQUENCY
80
MAX4990E toc03
20
18
TOTAL INPUT CURRENT (mA)
16
14
12
10
8
6
4
2
0
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
20
TOTAL INPUT CURRENT (mA)
TOTAL INPUT CURRENT (mA)
16
60
C
CS
= 2.2nF
40
C
CS
= 4.7nF
20
C
CS
= 4.7nF
225
12
150
8
75
4
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
0
40
80
C
CS
= 2.2nF
120
160
0
200
BOOST CONVERTER FREQUENCY (kHz)
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
MAX4990E toc04
SHUTDOWN CURRENT
vs. TEMPERATURE
DIM = EN = 0V
MAX4990E toc05
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
DIM = 1.3V
DIM = 1.0V
200
150
100
50
0
DIM = 0.8V
DIM = 0.6V
MAX4990E toc06
1.0
DIM = EN = 0V
100
300
250
SHUTDOWN CURRENT (nA)
SHUTDOWN CURRENT (nA)
0.8
10
0.6
1
0.4
0.2
0.1
0
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
0.01
-40
-15
10
35
60
85
TEMPERATURE (°C)
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
- - - -
PEAK-TO-PEAK OUTPUT VOLTAGE
90% DUTY CYCLE
300
High-Voltage, ±15kV ESD-Protected
Electroluminescent Lamp Driver
MAX4990E
Typical Operating Characteristics (continued)
(V
DD
= +3.6V, C
LAMP
= 10nF, C
CS
= 3.3nF, L
X
= 220µH (I
SAT
= 170mA, R
S
= 5.5Ω), R
SLEW
= 390kΩ, DIM = V
DD
, C
SW
= 100pF,
C
EL
= 1.2nF, T
A
= +25°C, unless otherwise noted.)
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. TEMPERATURE
MAX4990E toc07
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. DIM VOLTAGE
V
DD
= 4.5V
MAX4990E toc08
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. DIM DUTY CYCLE
MAX4990E toc09
210
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
205
200
195
190
185
180
-40
-15
10
35
60
300
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
250
200
150
100
50
300
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
250
200
150
100
f
DIM
= 1MHz
50
0
f
DIM
= 200kHz
85
0
0.35
0.54
0.73
0.92
1.11
1.30
20
40
60
80
TEMPERATURE (°C)
DIM VOLTAGE (V)
DIM DUTY CYCLE (%)
RMS OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX4990E toc10
AVERAGE OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX4990E toc11
AVERAGE OUTPUT VOLTAGE
vs. TEMPERATURE
-100
AVERAGE OUTPUT VOLTAGE (mV)
-200
-300
-400
-500
-600
-700
-800
-900
-1000
MAX4990E toc12
120
100
RMS OUTPUT VOLTAGE (V)
80
60
40
20
0
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
0
-100
AVERAGE OUTPUT VOLTAGE (mV)
-200
-300
-400
-500
-600
-700
-800
-900
-1000
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
EL SWITCHING FREQUENCY vs.C
EL
MAX4990E toc13
EL SWITCHING FREQUENCY
vs. SUPPLY VOLTAGE
MAX4990E toc14
EL SWITCHING FREQUENCY
vs. TEMPERATURE
MAX4990E toc15
500
EL SWITCHING FREQUENCY (Hz)
R
SLEW
= 390kΩ
190
EL SWITCHING FREQUENCY (Hz)
190
EL SWITCHING FREQUENCY (Hz)
400
185
185
300
180
180
200
175
100
175
0
0.5
1.0
1.5
C
EL
(nF)
2.0
2.5
170
2.4
3.0
3.6
4.2
4.8
5.4
SUPPLY VOLTAGE (V)
170
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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