Rainbow Electronics MAX14514 User Manual

General Description

The MAX14514 is a high-voltage DC-AC converter ideal
for driving two electroluminescent (EL) lamps. The
MAX14514 features a +2.7V to +5.5V input range that
allows the device to accept a wide variety of voltage
sources, including single-cell lithium-ion (Li+) batteries.
The lamp outputs of the device generate up to 300V

P-P

for maximum lamp brightness.

The MAX14514 utilizes an inductor-based boost con­verter to generate the high voltage necessary to drive EL
lamps and allows the use of a 220µH inductor to effec­tively drive total combined lamp sizes of up to 20nF.

The MAX14514 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 panels. An external resistor controls the slew­rate of the rising and falling edges of the AC drive
waveform to reduce audible noise output. The high-volt­age outputs are ESD protected up to ±15kV Human
Body Model, ±4kV IEC 61000-4-2 Air Gap Discharge,
and ±4kV IEC 61000-4-2 Contact Discharge.

The MAX14514 features dimming/enable controls
(DIM1, DIM2) for each output to allow the user to set
the peak-to-peak output voltage with a PWM signal, a
DC analog voltage, or a resistor connected from DIM_
to GND. The MAX14514 also provides a slow turn-on/­off feature that slowly ramps the output voltage applied
to the lamp when enabled or disabled.

The MAX14514 enters a low-power shutdown mode
when the EN and DIM_ inputs are connected to GND.
The device also features thermal shutdown if the die
temperature exceeds +158°C (typ).

The MAX14514 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.

Applications

Keypad Backlighting

LCD Backlighting

PDAs/Smartphones

Automotive Instrument Clusters

Features

♦ Dual ±15kV ESD-Protected EL Lamp Outputs

♦ 300V

P-P

Maximum Output for Highest Brightness

♦ +2.7V to +5.5V Input Voltage Range

♦ Resistor Adjustable Slew-Rate Control

♦ Resistor Adjustable Lamp and Switching

Converter Frequencies

♦ DIM Input for Controlling Output Voltage Through

DC Analog Voltage, PWM, or Resistor to GND

♦ Capacitor Adjustable Soft Turn-On/-Off

♦ Low 150nA Shutdown Current

♦ Thermal Shutdown

♦ Space Saving, 14-Pin, 3mm x 3mm TDFN Package

MAX14514

Dual Electroluminescent Lamp Driver

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration

19-4466; Rev 0; 2/09

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX14514ETD+ -40°C to +85°C 14 TDFN-EP*

Ordering Information

+

Denotes a lead(Pb)-free/RoHS-compliant package.

*

EP = Exposed pad.

MAX14514

TDFN-EP

(3mm x 3mm)

+

TOP VIEW

*EP = EXPOSED PAD. CONNECT EP TO GND OR LEAVE UNCONNECTED.

245

13 11 10

EN

V2COM

DIM2

EL

SW

1

14

SLEWDIM1

3

12

V

1

CAP

6

9

CSV

DD

7

8

LXGND

*EP

For information on other Maxim products, visit Maxim’s website at www.maxim-ic.com.

MAX14514

Dual Electroluminescent Lamp Driver

2 _______________________________________________________________________________________

Typical Application Circuit

R

BASEBAND/PMIC

DIM1

SLEW

SLEW

COM

EN

V

1

CCS = 3.3nF

EL LAMP
C

LAMP

= 10nF

2

CS

LX

EL LAMP
C

LAMP

= 10nF

DIM2

C

CAP

CAP

C

EL

EL V

C

SW

V

DD

0.1µF

V

BAT

4.7µF

SW

V

DD

GND

MAX14514

LX = 220µH

MAX14514

Dual Electroluminescent Lamp Driver

_______________________________________________________________________________________ 3

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= +2.7V to +5.5V, C

LAMP_TOTAL

= 10nF, CCS= 3.3nF, LX= 220µH (I

SAT

= 170mA, RS= 5.5Ω), TA= -40°C to +85°C, unless oth-

erwise noted. Typical values are at V

DD

= +3.0V, TA= +25°C.) (Note 2)

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.

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer

board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial

.

(Voltages referenced to GND.)
V

DD

........................................................................-0.3V to +6.0V

CS, LX...................................................................-0.3V to +160V

V

1

, V2, COM................................................-0.3V to (VCS+ 0.3V)

SW, EL, DIM_, SLEW, CAP, EN ..................-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

Junction-to-Case Thermal Resistance (θ

JC

) (Note 1)

14-Pin TDFN...................................................................8°C/W

Junction-to-Ambient Thermal Resistance (θ

JA

) (Note 1)

14-Pin TDFN.................................................................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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Supply Voltage V

Input Supply Current I

Shutdown Supply Current I

Shutdown Inductor Supply
Current

Undervoltage Lockout V

Undervoltage Lockout Hysteresis V

EL OUTPUTS (V1, V2, COM)

Peak-to-Peak Output Voltage V_ - V

V1, V2 High-Side Switch On­Resistance

V1, V2 Low-Side Switch On­Resistance

COM High-Side Switch On­Resistance

COM Low-Side Switch On­Resistance

High-Side Switch Off-Leakage R

Low-Side Switch Off-Leakage R

EL Lamp Switching Frequency f

ESD Protection (COM, V1, V

2

Only)

DD

R

= 375kΩ, FEL = 200Hz,

IN

SHDN

I

LX_SHDN

UV

UV_HYST

COMVDD

R

ONHS_VNISOURCE

R

ONLS_VNISINK

R

ON HS _C OM ISOURCE

R

ON LS _C OM

ON HS _LEAKV1

ON LS _LE AKV1

EL

SLEW

(V1,V2) - V

COM

= 300V

EN = GND

EN = GND, LX = VDD, CS = V

VDD falling 1.8 2.1 2.3 V

= +3V

= 1mA 1.5 3.0 kΩ

= 1mA 0.7 2.0 kΩ

= 1mA 0.7 1.5 kΩ

I

= 1mA 0.4 1.0 kΩ

SINK

, V2, V

, V2, V

CEL = 872pF, R

= 0, VCS = 150V -1 +1 µA

COM

= 150V, VCS = 150V -1 +1 µA

COM

SLEW

Human Body Model ±15

IEC 61000-4-2 Contact Discharge ±4

IEC 61000-4-2 Air-Gap Discharge ±4

2.7 5.5 V

P-P

TA = +25°C 40 150

= - 40°C to + 85°C 400

T

A

DD

700 µA

nA

1.5 µA

125 mV

V

= +0.5V 105 130 162

DIM_

V

= +1V 210 260 310

DIM_

= +1.3V 250 300 350

V

DIM_

= 375kΩ 210 250 290 Hz

kV

V

MAX14514

Dual Electroluminescent Lamp Driver

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.5V, C

LAMP_TOTAL

= 10nF, CCS= 3.3nF, LX= 220µH (I

SAT

= 170mA, RS= 5.5Ω), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

DD

= +3.0V, TA= +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

BOOST CONVERTER

Boost Switching Frequency f

Switch On-Resistance R

LX Leakage Current I

CS Input Current I

CONTROL INPUT (SW)

Input-Voltage High Threshold V

Input-Voltage Low Threshold V

Input Low Current I

Input High Current I

CONTROL INPUT (EL)

Input-Voltage High Threshold V

Input-Voltage Low Threshold V

Input Low Current I

Input High Current I

CONTROL INPUT (CAP)

CAP Switching Frequency f

Slow Turn-On Time t

Fast Turn-On CAP Threshold V

Nonfast Turn-On CAP Threshold

Input Leakage Current I

CONTROL INPUT (SLEW)

Force Voltage V

High-Voltage Output Slew Rate R

CONTROL INPUTS (DIM1, DIM2)

Input High Voltage V

Input Low Voltage V

Input Low Current I

Input High Current I

PWM Frequency Range 0.2 to 1 MHz

Low-Peak Detector Threshold V

Low-Peak Detector Hysteresis V

CS

SW

LX

CS

IH_CSWRSLEW

IL_CSWRSLEW

IL_CSW

IH_CSW

IH_CELRSLEW

IL_CELRSLEW

IL_CEL

IH_CEL

CAP

SLOW_ONRSLEW

FAST_CAPRSLEW

V

NON-

FAST_CAP

IH_CAP

FORCE

IH_DIM__

IL_DIM__

IL_DIM__VDIM_

IH_DIM__VDIM_

LPD

LPD_HYST

VDD = +3V

LX

CSW = 96pF, R

I

= 25mA, V

SINK

V

= +150V -1 +1 µA

LX

N o l oad , V

C S

= 375kΩ 80 100 120 kHz

SLEW

= +3V 20 Ω

DD

= + 150V , V

= 375kΩ 0.9 0.98 1.06 V

= 375kΩ 0.43 0.49 0.55 V

R

= 375kΩ, VCS = +78V, C

SLEW

V

= V

R
V

DIM_

SLEW

DIM_

DD

= 375kΩ, VCS = +78V, C

= V

DD

= 375kΩ 1.08 1.32 V

= 375kΩ 0.22 0.39 V

R

= 375kΩ 1.3 1.88 µA

SLEW

R

= 375kΩ 1.3 1.88 µA

SLEW

R

= 375kΩ, C

SLEW

= 375kΩ, C

CAP

CAP

= 375kΩ V

R

= 375kΩ 1.4 V

SLEW

CAP = V

DD,

R

SLEW

=

375kΩ

R

= 375kΩ 0.9 0.98 1.05 V

SLEW

= 375kΩ 32 V/100µs

SLEW

Max output voltage 1.3 V

Min output voltage 0.15 V

= 0, R

= V

= 375kΩ 2.2 2.6 3.0 µA

SLEW

DD

V

= +0.5V 52 65 81

DIM_

V

= +1V 105 130 155Output Regulation Voltage V

DIM_

V

= +1.3V 125 150 175

DIM_

E N

= 0, V

= 050µA

D IM _

= V

EL

EL

= V

DD,

DD,

43 79 µA

5 7.5 µA

= 1.25nF 180 300 410 Hz

= 1.25nF 0.3 s

- 0.35 V

D D

Normal operation 0.3 1 µA

Shutdown mode -100 100 nA

-1 +1 µA

0.13 0.35 V

100 mV

V

MAX14514

Dual Electroluminescent Lamp Driver

_______________________________________________________________________________________ 5

Typical Operating Characteristics

(VDD= +3.6V, TA= +25°C, unless otherwise noted.)

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.5V, C

LAMP_TOTAL

= 10nF, CCS= 3.3nF, LX= 220µH (I

SAT

= 170mA, RS= 5.5Ω), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

DD

= +3.0V, TA= +25°C.) (Note 2)

Note 2: All devices are 100% production tested at TA= +25°C. All temperature limits are guaranteed by design.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CONTROL INPUT (EN)

Input Logic-High Voltage V

Input Logic-Low Voltage V

IH_EN

IL_EN

1.4 V

0.3 V

THERMAL SHUTDOWN

Thermal Shutdown 158 °C

Thermal Shutdown Hysteresis 8°C

TOTAL INPUT CURRENT

vs. SUPPLY VOLTAGE

25

20

MAX14514 toc01

25

20

TOTAL INPUT CURRENT

vs. TEMPERATURE

INPUT CURRENT AND PEAK-TO-PEAK OUTPUT
VOLTAGE vs. BOOST CONVERTER FREQUENCY

MAX14514 toc02

80

60

PEAK-TO-PEAK OUTPUT

90% DUTY CYCLE

MAX14514 toc03

300

225

15

10

TOTAL INPUT CURRENT (mA)

5

0

2.7 5.5

3.4 4.1 4.8
SUPPLY VOLTAGE (V)

SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE

0.4
DIM1 = DIM2 = EN = 0V

0.35

0.3

0.25

0.2

0.15

SHUTDOWN CURRENT (nA)

0.1

0.05

0

2.7 5.5

3.4 4.1 4.8
SUPPLY VOLTAGE (V)

15

10

TOTAL INPUT CURRENT (mA)

5

0

-40 85

100

MAX14514 toc04

10

1

0.1

SHUTDOWN CURRENT (nA)

0.01

0.001

-40 85

TEMPERATURE (°C)

SHUTDOWN CURRENT

vs. TEMPERATURE

DIM1 = DIM2 = EN = 0V

TEMPERATURE (°C)

40

20

TOTAL INPUT CURRENT (mA)

35 60-15 10

0

40 200

80 120 160

BOOST CONVERTER FREQUENCY (kHz)

150

75

PEAK-TO-PEAK OUTPUT VOLTAGE (V)

0

PEAK-TO-PEAK OUTPUT VOLTAGE

vs. SUPPLY VOLTAGE

250

MAX14514 toc05

200

150

100

50

PEAK-TO-PEAK OUTPUT VOLTAGE (V)

0

35 60-15 10

2.7 5.5

DIM_ = 0.4V

3.4 4.1 4.8
SUPPLY VOLTAGE (V)

DIM = 1V

MAX14514 toc06

DIM_ = 0.7V

DIM = 0.5V