MAX4990ETD+ [MAXIM]
High-Voltage, 【15kV ESD-Protected Electroluminescent Lamp Driver; 高电压， 【 15kV ESD保护，电致发光灯驱动器
| 型号： | MAX4990ETD+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | High-Voltage, 【15kV ESD-Protected Electroluminescent Lamp Driver |
| 文件： | 总15页 (文件大小：221K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0886; Rev 0; 8/07
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
General Description
Features
♦ ESD-Protected EL Lamp Outputs
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.
15kV Human Body Model
4kV IEC 61000-4-2 Contact Discharge
15kV IEC 61000-4-2 Air-Gap Discharge
♦ 250V
(MAX) Output for Highest Brightness
P-P
♦ Wide +2.4V to +5.5V Input Voltage Range
♦ Resistor-Adjustable Slew-Rate Control for
Audible Noise Reduction
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.
♦ 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
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.
DC Analog Voltage, PWM, or Resistor to GND
♦ Capacitor Adjustable for Slow Turn-On/-Off
♦ Space-Saving Packages
14-Pin, 3mm x 3mm TDFN
Applications
Keypad Backlighting
MP3 Players
PDAs/Smartphones
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.
Automotive Instrument
Clusters
LCD Backlighting
ꢁin Configuration
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.
TOP VIEW
14 13 12 11 10
9
8
MAX4990E
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.
*EP
+
1
2
3
4
5
6
7
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.
TDFN-EP
*EP = EXPOSED PAD. CONNECT EP TO GND OR LEAVE UNCONNECTED.
Typical Application Circuits appear at end of data sheet.
Ordering Information
TOP
MARK
PKG
CODE
1ꢀ5k
PROTECTION
SLEW-RATE
CONTROL
PART
PIN-PACKAGE
DIM CONTROL
MAX4990ETD+
14 TDFN-EP (3mm x 3mm)
ADL
T1433-2
Yes
Yes
Yes
Note: The device operates over the -40°C to +85°C operating
temperature range.
+Denotes a lead-free package.
EP = Exposed paddle.
________________________________________________________________ Maxim Integrated Products
1
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, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
J .................................................................................41°C/W
A
V
...........................................................................-0.3V to +7V
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
DD
CS, LX...................................................................-0.3V to +160V
V , V .........................................................-0.3V to (V + 0.3V)
A
B
CS
DD
EN, EL, SLEW, DIM, SW.............................-0.3V to (V
+ 0.3V)
Continuous Power Dissipation (T = +70°C)
A
14-Pin TDFN (derate 24.4mW/°C above +70°C) ...... 1951mW
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.
MAX490E
ELECTRICAL CHARACTERISTICS
(V
DD
= +2.4V to +5.5V, C
= 10nF, C = 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), T = T
to T
, unless otherwise
MAX
LAMP
CS
X
SAT
S
A
MIN
noted. Typical values are at V
= +3.0V and T = +25°C.) (Note 1)
DD
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Power-Supply Voltage
V
2.4
5.5
V
DD
R
= 375kΩ, slope = 30V/100µs;
= 200Hz, V - V = 250V
A B P-P
SLEW
Power-Supply Current
I
350
µA
nA
nA
DD
f
EL
EN = 0V, DIM = 0V, T = +25°C
25
100
300
A
Shutdown Supply Current
I
SHDN
EN = 0V, DIM = 0V, T = -40°C to +85°C
A
Shutdown Inductor Supply
Current
ILX
EN = 0V, DIM = 0V, LX = V , CS = V
DD
1500
2.3
SHDN
DD
Undervoltage Lockout
UVLO Hysteresis
V
V
rising
1.8
2.1
V
LO
DD
V
125
mV
HYST
EL OUTPUTS (k - k )
A
B
V
V
V
= +3V, DIM = +0.5V
= +3V, DIM = +1V
= +3V, DIM = +1.3V
84
100
200
250
122
230
280
DD
DD
DD
Peak-to-Peak Output Voltage
V
- V
170
210
V
A
B
I
= 1mA, V = +10V,
CS
SINK
Pulldown Switch On-Resistance
Pullup Switch On-Resistance
R
R
50
700
-1
165
500
2200
+1
Ω
Ω
ONPD
ONPU
V , V < +0.6V, V
= +3V
A
B
DD
V
= +125V, I
= 1mA
1500
CS
SOURCE
V
V
= +125V, V = +125V, shutdown mode,
B
= +125V
A
I
LKG_NMOS
CS
Switch Off-Leakage
µA
V
= 0V, V = unconnected, shutdown
B
A
I
-60
+60
LKG_PMOS
mode, V = +125V
CS
V
= +0.1V, V = 0V, shutdown mode,
B
A
V , V Differential Resistor
V
AB_RES
2
7
MΩ
A
B
CS = unconnected
= 872pF, R = 375kΩ
SLEW
EL Lamp Switching Frequency
ESD Protection (V , V Only)
f
C
210
250
15
4
290
Hz
EL
EL
Human Body Model
IEC 61000-4-2 Contact Discharge
IEC 61000-4-2 Air-Gap Discharge
kV
A
B
15
2
_______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.4V to +5.5V, C
= 10nF, C = 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), T = T
to T
, unless otherwise
MAX
LAMP
CS
X
SAT
S
A
MIN
noted. Typical values are at V
= +3.0V and T = +25°C.) (Note 1)
DD
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
BOOST CONkERTER
V
V
V
= +3V, DIM = +0.5V forced externally
= +3V, DIM = +1V forced externally
= +3V, DIM = +1.3V forced externally
42
85
50
61
115
140
120
20
DD
DD
DD
Output Peak Voltage
V
100
125
100
V
CS
105
80
Boost Switching Frequency
Switch On-Resistance
LX Leakage Current
CS Input Current
f
C
= 96pF, R = 375kΩ
SLEW
kHz
Ω
SW
SW
R
I
= 25mA, V
= +3V
DD
LX
SINK
I
V
= +125V
-1
+1
µA
µA
LX
LX
I
No load, V = +125V, EN = 0V, DIM = 0V
50
CS
CS
CONTROL INPUT SW
Input Voltage-High Threshold
Input Voltage-Low Threshold
V
R
R
R
= 375kΩ
0.9
0.98
0.49
1.06
0.55
V
V
IH_SW
SLEW
SLEW
V
= 375kΩ
0.43
IL_SW
= 375kΩ, CS = +40V, EL = V
DD
SLEW
DD,
Input Low Current
Input High Current
I
43
77
µA
µA
IL_SW
DIM = V
R
= 375kΩ, CS = +40V, EL = V
DD
,
SLEW
DD
I
5.0
7.5
IH_SW
DIM = V
CONTROL INPUT EL
Input Voltage-High Threshold
Input Voltage-Low Threshold
Input Low Current
V
R
R
R
R
= 375kΩ
= 375kΩ
= 375kΩ
= 375kΩ
1.08
0.22
1.2
1.32
0.39
1.87
1.87
V
IH_CEL
SLEW
SLEW
SLEW
SLEW
V
V
IL_CEL
IL_CEL
IH_CEL
I
µA
µA
Input High Current
I
1.2
CONTROL INPUT SLEW
Force Voltage
V
I
= 20µA
0.89
1.3
0.95
30
1.04
V
FORCE
SOURCE
High-Voltage Output Slew Rate
CONTROL INPUT DIM
Input Logic-High Voltage
Input Logic-Low Voltage
Input Low Current
R
= 375kΩ
V/100µs
SLEW
V
Output voltage (max)
Output voltage (off)
V
V
IH_DIM
V
0.15
3.0
+1
IL_DIM
IL_DIM
IH_DIM
I
V
V
= 0V, R
= 375kΩ
2.22
-1
µA
µA
MHz
V
DIM
DIM
SLEW
Input High Current
I
= V
DD
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
0.2 to 1
100
V
0.15
1.2
0.35
LPD
V
mV
LPD_HYST
V
V
IH_EN
V
0.2
+1
+1
V
IL_EN
IL_EN
IH_EN
I
-1
-1
µA
µA
Input High Current
I
_______________________________________________________________________________________
3
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.4V to +5.5V, C
= 10nF, C = 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), T = T
to T
, unless otherwise
MAX
LAMP
CS
X
SAT
S
A
MIN
noted. Typical values are at V
= +3.0V and T = +25°C.) (Note 1)
DD
A
PARAMETER
THERMAL SHUTDOWN
Thermal Shutdown
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
158
8
°C
°C
Thermal Shutdown Hysteresis
Note 1: Specifications at T = -40°C are guaranteed by design and not production.
A
MAX490E
Typical Operating Characteristics
(V
DD
= +3.6V, C
= 10nF, C
= 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), R
= 390kΩ, DIM = V , C
= 100pF,
LAMP
CS
X
SAT
S
SLEW
DD
SW
C
EL
= 1.2nF, T = +25°C, unless otherwise noted.)
A
TOTAL INPUT CURRENT AND
PEAK-TO-PEAK OUTPUT VOLTAGE
TOTAL INPUT CURRENT
vs. SUPPLY VOLTAGE
TOTAL INPUT CURRENT
vs. TEMPERATURE
vs. BOOST CONVERTER FREQUENCY
MAX4990E toc03
20
80
60
40
20
0
300
225
150
75
20
- - - - PEAK-TO-PEAK OUTPUT VOLTAGE
90% DUTY CYCLE
18
16
14
12
10
8
16
12
8
C
= 2.2nF
= 4.7nF
CS
CS
C
C
= 4.7nF
CS
6
C
4
4
2
= 2.2nF
120
CS
0
200
0
0
2.4
3.0
3.6
4.2
4.8
5.4
-40
-15
10
35
60
85
40
80
160
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
BOOST CONVERTER FREQUENCY (kHz)
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
SHUTDOWN CURRENT
vs. TEMPERATURE
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
100
10
1.0
0.8
0.6
0.4
0.2
0
300
250
200
150
100
50
DIM = EN = 0V
DIM = EN = 0V
DIM = 1.3V
DIM = 1.0V
DIM = 0.8V
1
DIM = 0.6V
0.1
0.01
0
2.4
3.0
3.6
4.2
4.8
5.4
2.4
3.0
3.6
4.2
4.8
5.4
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
Typical Operating Characteristics (continued)
(V
DD
= +3.6V, C
= 10nF, C = 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), R
= 390kΩ, DIM = V , C
= 100pF,
LAMP
CS
X
SAT
S
SLEW
DD
SW
C
EL
= 1.2nF, T = +25°C, unless otherwise noted.)
A
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. TEMPERATURE
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. DIM VOLTAGE
PEAK-TO-PEAK OUTPUT VOLTAGE
vs. DIM DUTY CYCLE
210
205
200
195
190
185
180
300
300
V
DD
= 4.5V
250
200
150
100
50
250
200
150
100
50
f
= 200kHz
DIM
f
= 1MHz
DIM
0
0
-40
-15
10
35
60
85
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
AVERAGE OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
AVERAGE OUTPUT VOLTAGE
vs. TEMPERATURE
0
-100
-200
-300
-400
-500
-600
-700
-800
-900
-1000
0
-100
-200
-300
-400
-500
-600
-700
-800
-900
-1000
120
100
80
60
40
20
0
2.4
3.0
3.6
4.2
4.8
5.4
2.4
3.0
3.6
4.2
4.8
5.4
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
EL SWITCHING FREQUENCY
vs. SUPPLY VOLTAGE
EL SWITCHING FREQUENCY
vs. TEMPERATURE
EL SWITCHING FREQUENCY vs.C
EL
190
185
180
175
170
500
400
300
200
100
0
190
185
180
175
170
R
= 390kΩ
SLEW
2.4
3.0
3.6
4.2
4.8
5.4
0.5
1.0
1.5
(nF)
2.0
2.5
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
C
TEMPERATURE (°C)
EL
_______________________________________________________________________________________
5
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
Typical Operating Characteristics (continued)
(V
DD
= +3.6V, C
= 10nF, C = 3.3nF, L = 220µH (I
= 170mA, R = 5.5Ω), R
= 390kΩ, DIM = V , C
= 100pF,
LAMP
CS
X
SAT
S
SLEW
DD
SW
C
EL
= 1.2nF, T = +25°C, unless otherwise noted.)
A
BOOST CONVERTER FREQUENCY
vs. SUPPLY VOLTAGE
BOOST CONVERTER FREQUENCY
vs. TEMPERATURE
BOOST CONVERTER FREQUENCY vs. C
SW
110
160
120
80
110
105
100
95
R
SLEW
= 390kΩ
105
100
95
MAX490E
40
90
0
90
-40
-15
-10
35
60
85
80
115
150
(pF)
185
220
2.4
3.0
3.6
4.2
4.8
5.4
TEMPERATURE (°C)
C
SUPPLY VOLTAGE (V)
SW
OUTPUT VOLTAGE SLOPE
vs. SUPPLY VOLTAGE
OUTPUT VOLTAGE SLOPE
vs. TEMPERATURE
OUTPUT VOLTAGE SLOPE vs. R
SLEW
40
35
30
25
20
32
30
28
26
24
22
32
30
28
26
24
22
15
10
5
0
300 400 500 600
R
800 900 1000
700
2.4
3.0
3.6
4.2
4.8
5.4
-40
-15
10
35
80
85
(kΩ)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SLEW
TYPICAL V , V , AND
BRIGHTNESS AND TOTAL INPUT CURRENT
A
B
V - V WAVEFORMS
SLOW TURN-ON/-OFF TIME vs. C
vs. SUPPLY VOLTAGE
A
B
DIM
MAX4990E toc24
MAX4990E toc23
25
20
15
10
5
30
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
R
= 390kΩ
- - - - SUPPLY CURRENT
DIM
C
= 20nF
LAMP
26
22
18
14
10
V
- V
B
A
t
ON
100V/div
V
A
50V/div
V
B
50V/div
t
OFF
0
1ms/div
0
0.6
1.2
1.8
(μF)
2.4
3.0
3.6
2.4
3.0
3.6
4.2
4.8
5.4
C
SUPPLY VOLTAGE (V)
DIM
6
_______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
ꢁin Description
PIN
NAME
FUNCTION
High-Voltage Slew-Rate Control. Connect an external resistor, R
the V and V high-voltage outputs.
, to GND to set the slew rate of
SLEW
1
SLEW
A
B
Enable Input. Drive EN > +1.2V and DIM > +0.35V to turn on the device. Drive EN < +0.2V and DIM <
+0.15V to turn off the device.
2
3
EN
EL Panel Dimming Control. Apply a PWM signal or DC analog control signal, or connect a resistor to
GND to adjust peak-to-peak output voltage. Use DIM together with EN to control device shutdown
(see Shutdown section).
DIM
EL Voltage Switching Frequency. Connect an external capacitor, C , to GND or drive with an external
EL
oscillator to set the switching frequency of the V and V high-voltage outputs. Connect EL to GND to
4
5
EL
A
B
shut off the EL oscillator. Drive EL high to keep alternatively V or V output high.
A
B
Boost-Converter Switching Frequency. Connect an external capacitor, C , to GND or drive with an
SW
external oscillator to set the switching frequency of the boost converter. Connect SW to GND to shut
off the boost oscillator. Do not keep SW high to avoid LX shorting to GND, which causes the internal
die temperature to increase. The MAX4990E is protected by entering a themal-shutdown state. (See
the Thermal Short-Circuit Protection section.)
SW
6
7
V
Power-Supply Voltage
Ground
DD
GND
Internal Switching DMOS Drain Connection. Connect LX to a switching inductor and an anode of a
rectifying diode.
8
LX
9, 11, 13
N.C.
CS
No Connection. Leave N.C. unconnected.
10
12
14
EP
High-Voltage Supply. Connect CS to output capacitor of boost converter.
V
V
High-Voltage EL Panel Output. Connect to non-V side of EL lamp.
A
B
A
High-Voltage EL Panel Output. Connect to non-V side of EL lamp.
B
EP
Exposed Pad. Connect exposed pad to GND.
The MAX4990E uses a high-voltage full-bridge output
Detailed Description
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 allows programma-
bility of the EL Lamp output frequency by applying a
clock signal to the EL input. Applying a clock signal to
the EL input allows the switching frequency of the lamp
to take the frequency of the clock signal divided by 4 to
switch at the EL input frequency divided by 4.
The MAX4990E high-voltage DC-AC converter is ideal
for driving 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 sin-
gle cell Li+ batteries and higher voltage battery charg-
ers. 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 that allows for the use of a 220µH inductor to gen-
erate the high voltage necessary to drive an EL lamp.
The boost converter switching frequency is set with the
combination of an external capacitor connected from
the SW input to GND and an external resistor connect-
ed from SLEW to GND. Applying a PWM signal to the
SW input allows the switching frequency of the boost
converter to take the frequency of the PWM signal.
The MAX4990E uses a proprietary acoustic noise-
reduction circuit to control the slew rate of the AC volt-
age, reducing audible noise from the EL panel. The
slew rate is set with an external resistor connected from
SLEW to GND.
The MAX4990E enters a low-power shutdown mode
(100nA max) when EN and DIM inputs are connected
_______________________________________________________________________________________
7
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
Functional Diagram
V
DD
LX
SWITCH
SW
N
OSCILLATOR
TIMEOUT
+
-
CS
EL
EL
MAX490E
REF
OSCILLATOR
HIGH ESD
PROTECTION
V
V-I
SENSE
V
V
SLEW
EN
A
CONVERTER
-
+
H-BRIDGE
LOW-POWER
SHUTDOWN
HIGH ESD
PROTECTION
B
DMOS
DRIVER
PWM
CONVERTER
DIM
LOW PEAK
DETECTOR
SHUTDOWN
THERMAL
SHUTDOWN
NO-OPERATION
SIGNAL
GND
MAX4990E
UVLO
TIMEOUT LOW-POWER
SHUTDOWN
to GND. The MAX4990E also enters thermal shutdown
if the die temperature rises above +158°C.
The device uses resistor R
to set the bias current
SLEW
used as a reference current for the MAX4990E internal
circuitry. The reference current directly affects the slew
rate of the EL lamp output. Increasing the value of
The MAX4990E features an EL lamp dimming control
(DIM) that allows the user to set the EL output voltage
with a PWM, DC analog voltage, or a resistor connect-
ed to GND. A capacitor placed in parallel to the resistor
on the DIM input allows the user to program a slow
turn-on/-off time of the MAX4990E’s outputs to generate
a soft fade-on/fade-off effect of the EL lamp.
R
decreases the slew rate, and decreasing the
SLEW
SLEW
value of R
increases the slew rate. (See the R
SLEW
Resistor Selection section on how to select R
.)
SLEW
The MAX4990E EL lamp output frequency uses an
internal EL oscillator to set the desired frequency. The
output frequency is adjusted by either 1) the combina-
tion of a resistor from SLEW to GND and an external
capacitor from the EL input to GND, or 2) by driving a
clock signal directly into the EL input. (See the C
Capacitor Selection section for choosing the C
capacitor value.)
The high-voltage outputs are ESD protected up to
15kV Human Body Model, 15kV Air-Gap Discharge,
and 4kV Contact Discharge, as specified in the IEC
61000-4-2 specification.
EL
EL
EL Output Voltage
The slew rate, frequency, and peak-to-peak voltage of the
MAX4990E EL lamp outputs are programmed through a
combination of external components and/or DC inputs.
The peak-to-peak voltage of the EL lamp output is var-
ied from 70V to 250V by applying an external DC
P-P
P-P
voltage ranging from +0.35V to +1.3V to the DIM input.
8
_______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
Increasing the voltage on the DIM input increases the
nected from the DIM input to GND, a PWM signal
applied to the DIM input, or a DC voltage applied to the
peak-to-peak voltage, and decreasing the voltage on
the input decreases the peak-to-peak voltage. The EL
lamp peak-to-peak voltage is also adjusted by applying
a PWM signal to the DIM input. The duty cycle of the
PWM determines the EL lamp output peak-to-peak volt-
age. As the duty cycle is increased, the peak-to-peak
output voltage is increased, and as the duty cycle is
decreased, the peak-to-peak voltage is decreased. The
MAX4990E also features a slow turn-on and slow turn-off
time feature that is enabled by connecting a resistor and
capacitor from DIM to GND (see the Typical Application
DIM input. (See the R
Selection section.)
Resistor and C
Capacitor
DIM
DIM
The duty cycle of a PWM signal to the DIM input is
internally translated into a DC voltage with the 0 to
+1.22V range. The DIM input accepts the frequency
range of 200kHz to 1MHz. As the duty cycle increases,
the peak-to-peak voltage of the output increases, and
as the duty cycle decreases, the peak-to-peak voltage
of the output decreases.
The peak-to-peak voltage is adjusted by applying a DC
voltage to the DIM input. Increasing the voltage on DIM
increases the peak-to-peak output, and decreasing the
voltage on DIM decreases the peak-to-peak output
voltage.
Circuits and the R
Resistor and C
Capacitor
DIM
DIM
Selection section). This slow turn-on/-off feature causes
the peak-to-peak voltage of the EL outputs to slowly rise
from zero to the maximum set value when the device is
enabled. This feature also causes the peak-to-peak volt-
age of the EL outputs to fall from the maximum set value
to zero when the device is placed into shutdown. The
slow rise and fall of the peak-to-peak EL output voltage
creates a soft fade-on and fade-off of the EL lamp,
rather than an abrupt change in brightness.
The DIM input, in combination with the EN input, con-
trols the shutdown mode of the MAX4990E shutdown.
(See the Shutdown section.)
ꢀlow Turn-On, ꢀlow Turn-Off
The MAX4990E provides a slow turn-on/-off feature by
connecting a resistor in parallel with a capacitor con-
Boost Converter
The MAX4990E boost converter consists of an external
nected from the DIM input to GND (see the R
DIM
inductor from V
to the LX input, an internal DMOS
Resistor and C
Capacitor Selection section). When
DD
DIM
switch, an external diode from LX to the CS output, an
external capacitor from the CS output to GND, and the
EN is driven high, the reference current I (set by
B
R
) is used to charge capacitor C
. When EN is
DIM
SLEW
EL lamp, C
, connected to the EL lamp outputs.
driven to GND, I is removed, and the voltage on the
LAMP
B
When the DMOS switch is turned on, LX is connected
to GND, and the inductor is charged. When the DMOS
switch is turned off, the energy stored in the inductor is
capacitor C
stant of R
and resistor decays with a time con-
DIM
x C
. A slow turn-on effect is seen by
DIM
DIM
driving EN high. The slow rise and fall of the voltage on
DIM during transitions on the EN input modulates the
peak-to-peak voltage of the EL outputs, creating a soft
fade-on/-off effect at the EL lamp.
transferred to the capacitor C and the EL lamp.
CS
Note: Keeping SW high shorts LX to GND, causing the
internal die temperature to increase. The MAX4990E is
protected by entering a thermal-shutdown state (See
the Thermal Short-Circuit Protection section.)
ꢀhutdown
The MAX4990E features an enable logic input, EN, to
enable and disable the device. To enable the device,
apply +1.2V or greater to the EN input and +0.35V or
greater to the DIM input. To place the device in shut-
down, apply +0.2V or less to the EN input, and +0.15V
or less to the DIM input.
The MAX4990E boost converter frequency uses an
internal switch oscillator to set the desired frequency of
the boost converter. The boost converter frequency is
adjusted by either 1) the combination of a resistor from
SLEW to GND and an external capacitor from SW to
GND, or 2) by driving a PWM signal directly into the SW
input. When SW is driven with an external PWM signal
at a suggested 90% duty cycle, the boost converter fre-
quency is changed to the frequency of the external
Undervoltage Loc5out (UVL0)
The MAX4990E has a UVLO threshold of +2.1V (typ).
When V
falls below +2.1V (typ), the device enters a
DD
nonoperative mode.
PWM signal. (See the C
Capacitor Selection section
SW
for choosing the C
capacitor value.)
SW
Thermal ꢀhort-Circuit ꢁrotection
The MAX4990E enters a nonoperative mode if the inter-
nal die temperature of the device reaches or exceeds
+158°C (typ). The device turns back on when the inter-
nal die temperature cools to +150°C.
Dimming Control
The MAX4990E features a dimming control input, DIM,
that controls the peak-to-peak voltage on the lamp out-
puts V and V . DIM is controlled by a resistor con-
A
B
_______________________________________________________________________________________
9
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
±±15V EꢀD ꢁrotection
Machine Model
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The EL lamp driver outputs of the MAX4990E
have extra protection against static electricity. Maxim’s
engineers have developed state-of-the-art structures to
protect these pins against ESD of 15kV without dam-
age. The ESD structures withstand high ESD in all
states: normal operation, shutdown, and powered
down. After an ESD event, the MAX4990E keep working
without latchup or damage.
The machine model for ESD tests all pins using a 200pF
storage capacitor and zero discharge resistance.
The objective is to emulate the stress caused when I/O
pins are contacted by handling equipment during test
and assembly. Of course, all pins require this protection.
The Air-Gap test involves approaching the device with a
charged probe. The Contact Discharge method connects
the probe to the device before the probe is energized.
MAX490E
Design ꢁrocedure
L
Inductor ꢀelection
X
ESD protection can be tested in various ways. The
transmitter EL lamp outputs of the MAX4990E are char-
acterized for protection to the following limits:
The recommended inductor values are 220µH/330µH.
For most applications, series resistance (DCR) should
be below 8Ω for reasonable efficiency. Do not exceed
the inductor’s saturation current.
•
•
•
15kV using the Human Body Model
4kV IEC 61000-4-2 Contact Discharge
15kV IEC 61000-4-2 Air-Gap Discharge
R
Resistor ꢀelection
ꢀLEW
To help reduce audible noise emission by the EL lamp,
the MAX4990E features a slew-rate control input
(SLEW) that allows the user to set the slew-rate of the
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
high-voltage outputs, V and V by connecting a
A
B,
resistor, R
, from the SLEW input to GND. R
SLEW
SLEW
precisely sets the reference current I that is used to
B
Human Body Model
Figure 1a shows the Human Body Model, and Figure
1b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩ resistor.
charge and discharge the capacitances at the SW
input and EL input, and is used as a reference current
for internal circuitry. The reference current is related to
R
by the following equation: I = 1V/R
.
SLEW
SLEW
B
Decreasing the value of R
increases I and
SLEW
B
increases the slew rate at the EL lamp output. Increasing
the value of R decreases I and decreases the
SLEW
B
slew rate at the EL lamp output. The output slew rate is
related to R by the following equation:
IEC 6±000-4-2
The IEC 61000-4-2 standard covers ESD testing and
performance of finished equipment. However, it does
not specifically refer to integrated circuits. The
MAX4990E assists in designing equipment to meet IEC
61000-4-2 without the need for additional ESD-protec-
tion components.
SLEW
⎛
⎞
V
11.25
R MΩ
SLEW
SlewRate
=
⎜
⎟
100μs
⎝
⎠
(
)
The ideal value for a given design varies depending on
lamp size and mechanical enclosure. Typically, the best
slew rate for minimizing audible noise is between
The major difference between tests done using the
Human Body Model and IEC 61000-4-2 is higher peak
current in IEC 61000-4-2 because series resistance is
lower in the IEC 61000-4-2 model. Hence, the ESD
withstand voltage measured to IEC 61000-4-2 is gener-
ally lower than that measured using the Human Body
Model. Figure 1c shows the IEC 61000-4-2 model, and
Figure 1d shows the current waveform for IEC 61000-4-
2 ESD Contact Discharge test.
10V/100µs and 20V/100µs. This results in R
values
SLEW
ranging from 1.125MΩ to 0.5625MΩ. For example, if the
desired slew rate is 20 (V/100µs), this leads to an R
SLEW
resistor value in MΩ of R
= 11.25/20V = 0.5625MΩ.
SLEW
Note: Connecting R
to GND will not damage the
SLEW
device. However, for the device to operate correctly,
R
SLEW
should be in the 100kΩ to 2.2MΩ range.
R
also affects the frequency of the boost converter
SLEW
(see the C
Capacitor Selection), the frequency of the
SW
EL lamp (see the C Capacitor Selection section), and
the peak-to-peak voltage of the EL lamp.
EL
10 ______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
R
R
1MΩ
R
D
330Ω
R
C
C
D
50MΩ TO 100MΩ
1500Ω
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
150pF
STORAGE
CAPACITOR
C
s
100pF
STORAGE
CAPACITOR
SOURCE
SOURCE
Figure 1c. IEC 61000-4-2 ESD Test Model
Figure 1a. Human Body ESD Test Model
I
100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
100%
90%
I
P
r
AMPS
36.8%
10%
0
10%
TIME
0
t
t = 0.7ns TO 1ns
r
RL
t
30ns
t
DL
60ns
CURRENT WAVEFORM
Figure 1b. Human Body Current Waveform
Figure 1d. IEC 61000-4-2 ESD Generator Current Waveform
Table 1. Inductor Vendors
INDUCTOR kALUE (µH)
kENDOR
TOKO
WEBSITE
PART
220
330
470
220
330
470
www.tokoam.com
www.coilcraft.com
www.coilcraft.com
www.coilcraft.com
www.coilcraft.com
www.coilcraft.com
D312C 1001BS-221M
DO1608C-334ML
DO1608C-474ML
LPS4018-224ML
LPS4018-334ML
LPS4018-474ML
Coilcraft
Coilcraft
Coilcraft
Coilcraft
Coilcraft
The peak-to-peak voltage is adjusted by connecting a
resistor from the SLEW input to GND together with a
resistor from the DIM input to GND. The equation relating
the peak-to-peak voltage to the resistors is the following:
R
Resistor and C
DIM
DIM
Capacitor ꢀelection
The MAX4990E provides a slow turn-on/-off feature by
connecting a resistor in parallel with a capacitor con-
nected from the DIM input to GND. The reference cur-
rent I is used to charge the resistor and capacitor.
When EN is driven to GND, I is removed, and the volt-
age across the capacitor and resistor decay with a time
constant of RC that provides a slow turn off of the EL
B
R
DIM
V
= 200 ×
P-P
B
R
SLEW
______________________________________________________________________________________ 11
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
lamp outputs. A slow turn-on effect is produced by dri-
ving EN high. Slow turn-on/-off time is related by the fol-
lowing equation:
Connect the SW input to GND to turn the switch oscilla-
tor of the boost converter off. Although the optimal f
depends on the inductor value, the suggested f
range is 20kHz to 150kHz.
SW
SW
t
t
= 2.6 x R
OFF
x C
DIM
ON
DIM DIM
= 1.2 x R
x C
DIM
Note: Driving SW with a logic-high causes LX to be dri-
ven to GND. Keeping SW high shorts LX to GND, caus-
ing the internal die temperature to increase. The
MAX4990E is protected by entering a thermal-shutdown
state. (See the Thermal Short-Circuit Protection section.)
For this equation to be valid, R
≤ 1.3.
/R
must be
DIM SLEW
C
Capacitor ꢀelection
Cꢀ
C
CS
is the output of the boost converter and provides
MAX490E
C
Capacitor ꢀelection
B
the high-voltage source for the EL lamp. Connect a
3.3nF capacitor from CS to GND and place as close to
the CS input as possible. When using an inductor value
larger than 220µH, it may be necessary to increase the
Bypass V
with a 0.1µF ceramic capacitor as close to
DD
the IC as possible and a 4.7µF ceramic capacitor as
close to the inductor as possible
C
. For a LX = 470µH and C
= 20nF, a C
LAMP CS
CS
Diode ꢀelection
Connect a diode, D , from the LX node to CS to rectify
1
ranging from 3.3nF to 6.8nF is recommended.
the boost voltage on CS. The diode should be a fast-
recovery diode that is tolerant to +150V.
C
Capacitor ꢀelection
EL
The MAX4990E EL lamp output frequency is set by
connecting a capacitor from the EL input to GND
together with a resistor from SLEW to GND or by driving
the EL input with an external clock (0 to +1.5V). The EL
EL Lamp ꢀelection
EL lamps have a capacitance of approximately 2.5nF to
3.5nF per square inch. The MAX4990E effectively
charges capacitance ranging from 2nF to 20nF.
lamp output frequency is related to the C capacitor
EL
by the following equation:
Applications Information
0.0817
ꢁCB Layout
Keep PCB traces as short as possible. Ensure that
bypass capacitors are as close to the device as possi-
ble. Use large ground planes where possible.
f
=
EL
R
×C
EL
SLEW
For example, an R
= 375kΩ and a C capacitor
EL
value of 1000pF equals an EL lamp output frequency of
= 217Hz.
SLEW
F
EL
Chip Information
C
Capacitor ꢀelection
ꢀW
The boost converter switching frequency is set by con-
necting a capacitor from the SW input to GND, together
with the resistance from the SLEW input to GND, or driving
the SW input with an external clock (0 to +1.5V). The
switching frequency of the boost converter is related to the
capacitor from SW to GND by the following equation:
PROCESS: BiCMOS-DMOS
3.61
f
=
SW
R
×C
SW
SLEW
12 ______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
Typical Application Circuits
R
SLEW
1
14
SLEW
EN
V
A
2
3
4
5
6
7
13
12
11
10
9
EL LAMP
= 10nF
DIGITAL OUTPUT
N.C.
C
LAMP
DIM
EL
V
B
PWM OR V
BIAS
C
C
EL
MAX4990E
N.C.
CS
μC
OR ASIC
SW
SW
C
CS
= 3.3nF
V
DD
N.C.
LX
D
1
8
C
= 0.1μF
B
GND
V
DD
L
X
= 220μH
4.7μF
R
SLEW
1
2
3
14
SLEW
EN
V
A
13
12
11
10
9
EL LAMP
= 10nF
DIGITAL OUTPUT
N.C.
C
C
LAMP
DIM
V
B
DIM
MAX4990E
N.C.
CS
μC
OR ASIC
R
DIM
C
EL
4
5
6
EL
C
SW
SW
C
CS
= 3.3nF
N.C.
LX
D
1
V
DD
7
8
C
B
= 0.1μF
GND
V
DD
L
X
= 220μH
4.7μF
______________________________________________________________________________________ 13
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
ꢁac5age Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX490E
14 ______________________________________________________________________________________
High-Voltage, ±±15V EꢀD-ꢁrotected
Electroluminescent Lamp Driver
MAX490E
ꢁac5age Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PACKAGE VARIATIONS
COMMON DIMENSIONS
SYMBOL
A
MIN.
0.70
MAX.
0.80
PKG. CODE
T633-2
N
6
D2
E2
e
JEDEC SPEC
MO229 / WEEA
MO229 / WEEC
MO229 / WEEC
MO229 / WEED-3
MO229 / WEED-3
- - - -
b
[(N/2)-1] x e
1.90 REF
1.95 REF
1.95 REF
1.50±0.10
1.50±0.10
1.50±0.10
1.50±0.10
1.50±0.10
1.70±0.10
1.70±0.10
2.30±0.10
2.30±0.10
2.30±0.10
2.30±0.10
2.30±0.10
2.30±0.10
2.30±0.10
0.95 BSC
0.65 BSC
0.65 BSC
0.50 BSC
0.50 BSC
0.40 BSC
0.40 BSC
0.40±0.05
0.30±0.05
0.30±0.05
0.25±0.05
0.25±0.05
0.20±0.05
0.20±0.05
T833-2
8
D
E
2.90
2.90
3.10
3.10
T833-3
8
A1
0.00
0.20
0.05
0.40
T1033-1
T1033-2
T1433-1
T1433-2
10
10
14
14
2.00 REF
2.00 REF
2.40 REF
2.40 REF
L
k
0.25 MIN.
0.20 REF.
- - - -
A2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated ꢁroducts, ±20 ꢀan Gabriel Drive, ꢀunnyvale, CA 94086 408-737-7600 ____________________ 15
© 2007 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
SPRINGER
相关型号：
©2020 ICPDF网 联系我们和版权申明