Rainbow Electronics MAX16823 User Manual

General Description

The MAX16823 three-channel LED driver operates from a

5.5V to 40V input voltage range and delivers up to 70mA per channel to one or more strings of high-brightness LEDs (HBLEDs). Each channel’s current is programmable using an external current-sense resistor in series with the LEDs. Three DIM inputs allow a wide range of independent pulsed dimming in addition to providing the on and off control of the outputs. Wave-shaping circuitry reduces EMI while providing fast turn-on and turn-off times.

The MAX16823 is well suited for automotive applications requiring a high-voltage input and is able to withstand load-dump events up to 45V. On-board pass elements minimize external components while providing ±5% LED current accuracy. Additional features include an activehigh, open-drain LEDGOOD output for open LED detection, a +3.4V (±5%) regulated output with 4mA output current capability, short-circuit and thermal protections.

The MAX16823 is available in thermally enhanced 5mm x 5mm, 16-pin TQFN-EP and 16–pin TSSOP-EP packages and is specified over the -40°C to +125°C automotive temperature range.

Applications

Automotive Exterior: Rear Combination Lights

(RCLs), CHMSL

Automotive Interior: RGB Ambient Lighting,

Cluster Lighting, and LCD Backlighting Emergency Vehicle Warning Lights Navigation and Marine Indicators Architectural and Industrial Lighting

Features

 5.5V to 40V Operating Range  Adjustable Constant Output Current

(5mA to 70mA and Up to 2A with External BJT)

 ±5% Output Current Accuracy  Open LED Detection  Three Independent High-Voltage DIM Inputs  Three Integrated Pass Elements with Low

Dropout Voltage (0.7V max)

 Undervoltage Lockout  Output Short-Circuit Protection  3.4V Voltage Regulator with 4mA Capability  Accurate, Low 203mV Current Sense  Overtemperature Shutdown  -40°C to +125°C Operating Temperature Range

MAX16823

High-Voltage, 3-Channel Linear High-Brightness

LED Driver with Open LED Detection

________________________________________________________________

Maxim Integrated Products

Ordering Information

Typical Operating Circuit

19-0733; Rev 0; 1/07

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Pin Configurations appear at end of data sheet.

Denotes a lead-free package.

Future product—contact factory for availability.

EP = Exposed pad.

PART TEMP RANGE

MAX16823ATE+*

MAX16823AUE+ -40°C to +125°C 16 TSSOP-EP** U16E-3

-40°C to +125 °C 16 TQFN-EP** T1655-3

PINPACKAGE

PKG

CODE

REG

LEDGOOD

LGC

REG

DIM1

DIM2

DIM3

LEDGOOD

LGC

REG

MAX16823

GND

OUT1

OUT2

OUT3

CS1

CS2

CS3

CS1 CS2 CS3

MAX16823

High-Voltage, 3-Channel Linear High-Brightness LED Driver with Open LED Detection

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= 12V, C

REG

= 0.1µF, I

REG

= 0, C

LGC

= 15nF, V

DIM1

= V

DIM2

= V

DIM3

= 3.4V, R

CS_

= 2.85Ω from CS_ to GND, TJ= TA = -40°C

to +125°C, unless otherwise noted. Typical values are at T

= +25°C.) (Note 1)

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.

IN to GND ...............................................................-0.3V to +45V

OUT1, OUT2, OUT3, DIM1, DIM2,

DIM3 to GND ...........................................-0.3V to (V

+ 0.3V)

REG, LGC, LEDGOOD to GND ................................-0.3V to +6V

CS1, CS2, CS3 to GND .........................................-0.3V to +0.5V

OUT1, OUT2, OUT3 Short Circuited

to GND Duration (V

+ 16V)..........................................60min

Maximum Current into Any Pin

(except IN, OUT1, OUT2, OUT3)..................................±20mA

Continuous Power Dissipation (T

= +70°C)

16-Pin TQFN 5mm x 5mm

(derate 33.3mW/°C above +70°C).........................2666mW

16-Pin TSSOP (derate 26.1mW/°C above +70°C) ....2088.8mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Supply Voltage Range V

Undervoltage Lockout UVLO

Ground Current I

Guaranteed Output Current I

LED Current-Sense Accuracy 5mA ≤ I

Dropout Voltage (Note 2) ∆VDO

Output Current Slew Rate 8 mA/µs

Short-Circuit Current V

LEDGOOD

LEDGOOD Output Logic Low V

LGC Pullup Resistor 65 100 135 kΩ

LGC Input Upper Threshold V

LGC Input Lower Threshold V

LGC Pulldown Current V

LGC Clock Period C

DIMMING INPUT (DIM1, DIM2, DIM3)

DIM_ Logic-Input Bias Current I

DIM_ Input-Voltage High 2.4 V

DIM_ Input-Voltage Low 0.6 V

DIM_ Frequency 0 3 kHz

OUTPUTS (OUT1, OUT2, AND OUT3) (Note 3)

Turn-On Time DIM_ rising edge to 90% of OUT_ current 12 28 µs

Turn-Off Time DIM_ falling edge to 10% of OUT_ current 8 18 µs

Output Current Rise Time 10% to 90% 7 18 µs

Output Current Fall Time 90% to 10% 6 15 µs

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

OUT

DIM_

UTH

LTH

VIN rising 4.4 4.9 5.4

falling 4.0 4.6 5.2

= I

OUT1

OUT_

= 70mA, 6.5V ≤ VIN ≤ 40V 0.3 0.7

OUT_

= 70mA, 5.5V ≤ VIN ≤ 6.5V 0.3 0.8

OUT_

= 0V 180 mA

OUT_

= 2mA 0.4 V

SINK

> V

LGC

= 15nF 0.77 1.5 2.3 ms

LGC

5.5 40 V

= I

OUT2

≤ 70mA 5 %

UTH

= 70mA 1.5 3 mA

OUT3

70 mA

2.53 V

0.8 V

20 mA

-0.1 +0.1 µA

MAX16823

High-Voltage, 3-Channel Linear High-Brightness

LED Driver with Open LED Detection

_______________________________________________________________________________________ 3

Note 1: All devices 100% production tested at TJ= +25°C. Limits over the operating temperature range are guaranteed by design. Note 2: Dropout is measured as follows: Connect a resistor from OUT_ to CS_. Connect R

CS_

= 2.85Ω from CS_ to GND.

Set V

= V

OUT

+ 3V (record V

OUT

as V

OUTA

). Reduce VINuntil V

OUT

= 0.97 x V

OUTA

(record as V

INB

and V

OUTB

VDO = V

INB

- V

OUTB

Note 3: Output current rise and fall times are measured with a 62Ω series resistor from OUT_ to CS_. Note 4: Overtemperature protection does not function if the output of the 3.4V reference (REG) is shorted to ground.

ELECTRICAL CHARACTERISTICS (continued)

(VIN= 12V, C

REG

= 0.1µF, I

REG

= 0, C

LGC

= 15nF, V

DIM1

= V

DIM2

= V

DIM3

= 3.4V, R

CS_

= 2.85Ω from CS_ to GND, TJ= TA = -40°C

to +125°C, unless otherwise noted. Typical values are at T

= +25°C.) (Note 1)

Typical Operating Characteristics

(VIN= 12V, C

REG

= 0.1µF, I

REG

= 0, V

LGC

= unconnected, connect R

CS_

= 2.85Ω from CS_ to GND. Connect OUT_ to CS_ through

a resistor, T

= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C.)

CS_

vs. OUTPUT CURRENT

OUTPUT CURRENT (mA)

CS_

(V)

MAX16823 toc02

0 10203040506070

0.200

0.201

0.202

0.203

0.204

0.205

0.206

0.207

0.208

0.209

0.210

OUTPUT CURRENT vs. INPUT VOLTAGE

INPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

MAX16823 toc03

0 5 10 15 20 25 30 35 40

100

OUT

= 70mA

OUT

= 5mA

OUTPUT CURRENT vs. TEMPERATURE

TEMPERATURE (°C )

OUTPUT CURRENT (mA)

MAX16823 toc01

-40 -25 -10 5 20 35 50 65 80 95 110 125

100

LOAD

= 5mA

LOAD

= 35mA

LOAD

= 70mA

CURRENT SENSE

Regulated CS_ Voltage V

Input Current (CS1, CS2, CS3) Current out of CS_ +1.2 µA

OVERTEMPERATURE PROTECTION (Note 4)

Thermal Shutdown Temperature 155 °C

Thermal Shutdown Hysteresis 23 °C

3.4V REGULATOR (REG)

Output Voltage V

REG Short-Circuit Current V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CS_

REG

5mA ≤ I

OUT

_ ≤ 70mA 193 203 213 mV

3.275 3.41 3.547

0 ≤ I

≤ 4mA 3.221 3.38 3.547

REG

= 0V 13 mA

REG

MAX16823

High-Voltage, 3-Channel Linear High-Brightness LED Driver with Open LED Detection

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VIN= 12V, C

REG

= 0.1µF, I

REG

= 0, V

LGC

= unconnected, connect R

CS_

= 2.85Ω from CS_ to GND. Connect OUT_ to CS_ through

a resistor, T

= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C.)

DROPOUT VOLTAGE vs. TEMPERATURE

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

DROPOUT VOLTAGE (mV)

0.2

0.1

-40 -25 -10 5 20 35 50 65 80 95 110 125

SUPPLY CURRENT vs. TEMPERATURE

1.4 V

= V

= 0V

DIM3

VIN = 40V

VIN = 5.5V

TEMPERATURE (°C)

= 70mA

LOAD

TEMPERATURE (°C)

1.3

MAX16823 toc04

1.2

1.1

1.0

0.9

SUPPLY CURRENT (mA)

0.8

0.7

0.6

DIM1

DIM2

VIN = 20V

VIN = 12V

-40-25-105 203550658095110125

MAX16823 toc05

(V)

vs. TEMPERATURE

3.5

3.4

3.3

REG

3.2

3.1

3.0

-40 -25 -10 5 20 35 50 65 80 95 110 125

REG

LOAD

= 4mA

LOAD

TEMPERATURE (°C)

= 0

LOAD

= 1mA

MAX16823 toc06

vs. I

CS_

0.210

0.209

0.208

0.207

0.206

0.205

0.204

(V)

0.203

0.202

CS_

0.201

0.200

0.199

0.198

0.197

0.196

0.195 012345678910

REG

= 70mA

LOAD

(mA)

REG

200Hz DIMMED OPERATION (EXPANDED)

LOAD

VIN = 12V, DIM PULSED AT 200Hz (50% DUTY CYCLE)

= 70mA

MAX16823 toc10

MAX16823 toc07

DIM

2V/div

0V I

LOAD

50mA/div

vs. V

3.45

3.44

3.43

3.42

3.41

(V)

3.40

REG

3.39

3.38

3.37

3.36

3.35

= 1mA

REG

0 5 10 15 20 25 30 35 40

REG

= 0

REG

= 4mA

REG

(V)

200Hz DIMMED OPERATION (EXPANDED)

LOAD

VIN = 12V, DIM PULSED AT 200Hz (50% DUTY CYCLE)

= 70mA

MAX16823 toc11

MAX16823 toc08

DIM

2V/div

0V I

LOAD

50mA/div

330Hz DIMMED OPERATION

I VIN = 12V, DIM PULSED AT 33Hz (1% DUTY CYCLE)

20µs/div

LEDGOOD RESPONSE TIMES

LOAD

= 70mA

LGC

MAX16823 toc09

MAX16823 toc12

= 12V

= 15nF

DIM

2V/div

0V I

LED

50mA/div

DIM

5V/div

LEDGOOD

5V/div 0V

LGC

5V/div 0V

10µs/div

2ms/div

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