Rainbow Electronics MAX16803 User Manual

General Description

The MAX16803 current regulator operates from a 6.5V
to 40V input-voltage range and delivers up to a total of
350mA to one or more strings of high-brightness LEDs
(HB LEDs). The output current of the MAX16803 is
adjusted by using an external current-sense resistor in
series with the LEDs. A dimming input allows wide­range “pulsed” PWM operation. Wave-shaping circuitry
reduces EMI. The differential current-sense input
increases noise immunity. The MAX16803 is well suited
for applications requiring high-voltage input and is able
to withstand automotive load-dump events up to 40V.
An on-board pass element minimizes external compo­nents while providing ±3.5% output-current accuracy.
Additional features include a 5V regulated output and
short-circuit and thermal protection.

The MAX16803 is available in a thermally enhanced,
5mm x 5mm, 16-pin TQFN package and is specified
over the automotive -40°C to +125°C temperature range.

Applications

Automotive Interior: Map, Courtesy, and Cluster
Lighting

Automotive Exterior: Rear Combination Lights (RCLs)

Emergency Vehicle Warning Lights

Navigation and Marine Indicators

General Lighting

Signage, Gasoline Canopies, Beacons

Features

♦ +6.5V to +40V Operating Range
♦ Adjustable LED Current (35mA to 350mA)
♦ ±3.5% LED Current Accuracy
♦ High-Voltage DIM Pin for Dimming Interface
♦ Integrated Pass Element with Low-Dropout

Voltage (0.5V typ)

♦ +5V Regulated Output with 4mA Source

Capability

♦ Parallel Operation for LED Current > 350mA
♦ Differential LED Current Sense

♦ Low Shutdown Supply Current (12µA typ)

♦ Low 204mV Current-Sense Reference Reduces

Power Losses

♦ Wave-Shaped Edges Reduce Radiated EMI During

PWM Dimming

♦ Thermal Shutdown
♦ Output Short-Circuit Protection
♦ Available in Small, Thermally Enhanced,

5mm x 5mm, 16-Pin TQFN Package

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

MAX16803

High-Voltage, 350mA, High-Brightness LED

Driver with PWM Dimming and 5V Regulator

________________________________________________________________ Maxim Integrated Products 1

15

16

+

14

13

6

5

7

IN

N.C.

8

OUT

V5

CS+

GND

12

N.C.

4

12 11 9

EN

OUT

N.C.

N.C.

N.C.

N.C.

MAX16803

IN CS-

3

10

DIM

TQFN

TOP VIEW

Pin Configuration

Ordering Information

MAX16803

IN

OUT

V5

LEDs

R

SENSE

0.1µF

+6.5V TO +40V

+5V REG

CS+

0.1µF

CS-

DIM

PWM DIMMING

GND

EN

Simplified Diagram

19-0532; Rev 0; 5/06

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.

+Denotes lead-free package.
*EP = Exposed pad.

PART

TEMP RANGE

PIN-

PKG

CODE

MAX16803ATE+

T1655-3

PACKAGE

-40°C to +125°C 16 TQFN-EP*

MAX16803

High-Voltage, 350mA, High-Brightness LED
Driver with PWM Dimming and 5V Regulator

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= V

EN

= +12V, CV5= 0.1µF to GND, IV5= 0, V

CS-

= 0V, V

DIM

= +4V, connect R

SENSE

= 0.58Ω between CS+ and CS- (Note 1).

T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +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, OUT, DIM, and EN to GND ...............................-0.3V to +45V

CS+, CS-, V5 to GND ...............................................-0.3V to +6V

OUT Short Circuited to GND Duration

(at V

IN

= +16V) ........................................................60 minutes

Maximum Current Into Any Pin (except IN and OUT).........±20mA

Continuous Power Dissipation (T

A

= +70°C)

16-Pin TQFN (derate 33.3mW/

°

C above +70°C) ......2666.7mW

Operating Junction 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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Supply Voltage Range V

IN

(Note 2) 6.5

V

Ground Current I

G

I

LOAD

= 350mA 1.4 3 mA

Shutdown Supply Current I

SHDN

EN ≤ 0.6V 12 40 µA

Guaranteed Output Current I

OUT

R

SENSE

= 0.55Ω

mA

Output Current Accuracy 35mA < I

OUT

< 350mA

%

I

OUT

= 350mA (current pulsed),

12V < V

IN

< 40V

0.5 1.2

Dropout Voltage (Note 3) ∆VDO

I

OUT

= 350mA (current pulsed),

6.5V < V

IN

< 12V

0.5 1.5

V

Current rising, DIM rising to 4V 17

Output Current Slew Rate

Current falling, DIM falling to 0.6V 17

mA/µs

Short-Circuit Current V

OUT

= 0V, VIN = 12V

mA

LOGIC INPUT

EN Input Current I

EN

nA

EN Input Voltage High V

IH

2.8 V

EN Input Voltage Low V

IL

0.6 V

Turn–On Time t

ON

EN rising edge to 90% of OUT 80 µs

CURRENT SENSE (Note 4)

Regulated R

SENSE

Voltage V

RSNS

V

SENSE

= V

CS+

- V

CS-

mV

CS- Voltage Range

V

Input Current (CS+) V

CS+

= 220mV

µA

Input Current (CS-) V

CS+

= 220mV -84 µA

DIM Input Current 1µA

DIM Input Voltage High V

IH

4V

DIM Input Voltage Low V

IL

0.6 V

Turn-On Time t

ON

After DIM rising to 4V (Note 5) 52 µs

Turn-Off Time t

OFF

After DIM falling to 0.6V (Note 5) 38 µs

350

±3.5

40.0

400 600 800

196 203 210

-0.3 +4.1

100

+14

MAX16803

High-Voltage, 350mA, High-Brightness LED

Driver with PWM Dimming and 5V Regulator

_______________________________________________________________________________________ 3

Note 1: All devices 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design.
Note 2: Resistors were added from OUT to CS+ to aid with the power dissipation during testing.
Note 3: Dropout is measured as follows:

Connect R

O

= 27Ω from OUT to CS+. Connect R

SENSE

= 0.58Ω from CS+ to CS-. Set VIN= +12V (record V

OUT

as V

OUT1

).

Reduce VINuntil V

OUT

= 0.97 x V

OUT1

(record as V

IN2

and V

OUT2

). ∆VDO= V

IN2

- V

OUT2

.

Note 4: I

V5

= 0mA.

Note 5: t

ON

time includes the delay and the rise time needed for I

OUT

to reach 90% of its final value. t

OFF

time is the time needed

for I

OUT

to drop below 10%. See the Typical Operating Characteristics. tONand t

OFF

are tested with 13Ω from OUT to CST.

Note 6: Current regulation varies with V5 load (see the Typical Operating Characteristics).
Note 7: Thermal shutdown does not function if the output of the 5V reference is shorted to ground.

ELECTRICAL CHARACTERISTICS (continued)

(VIN= V

EN

= +12V, CV5= 0.1µF to GND, IV5= 0, V

CS-

= 0V, V

DIM

= +4V, connect R

SENSE

= 0.58Ω between CS+ and CS- (Note 1).

T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

THERMAL OVERLOAD

Thermal-Shutdown Temperature

°C

Thermal-Shutdown Hysteresis 23 °C

+5V REGULATOR

Output Voltage Regulation V5 (Note 6) 5.0

5.5 V

V5 Short-Circuit Current V5 = 0V (Note 7) 16 mA

Typical Operating Characteristics

(VIN= VEN= +12V, TA= +25°C, unless otherwise noted.)

OUTPUT CURRENT
vs. TEMPERATURE

MAX16803 toc01

TEMPERATURE (°C)

OUTPUT CURRENT (mA)

1109565 80-10 5 20 35 50-25

50

100

150

200

250

300

350

400

450

0

-40 125

I

LOAD

= 350mA

I

LOAD

= 35mA

I

LOAD

= 200mA

I

LOAD

= 100mA

(V

CS+

- V

CS-

) vs. OUTPUT CURRENT

MAX16803 toc02

OUTPUT CURRENT (mA)

(V

CS+

- V

CS-

) (V)

320290230 26080 110 140 170 20050

0.201

0.202

0.203

0.204

0.205

0.206

0.207

0.208

0.209

0.210

0.200
20 350

VIN = 12V

OUTPUT CURRENT

vs. INPUT VOLTAGE

MAX16803 toc03

INPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

35305 10 15 20 25

50

100

150

200

250

300

350

400

0

040

+155

5.27

MAX16803

High-Voltage, 350mA, High-Brightness LED
Driver with PWM Dimming and 5V Regulator

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VIN= VEN= +12V, TA= +25°C, unless otherwise noted.)

DROPOUT VOLTAGE

vs. TEMPERATURE

MAX16803 toc04

TEMPERATURE (°C)

DROPOUT VOLTAGE (V)

1109565 80-10 5 20 35 50-25

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0

-40 125

I

LOAD

= 350mA

SHUTDOWN CURRENT

vs. TEMPERATURE

MAX16803 toc05

TEMPERATURE (°C)

SHUTDOWN CURRENT (µA)

1109580655035205-10-25

5

10

15

20

25

30

35

0

-40 125

VIN = 40V

VIN = 20V

VIN = 12V

VIN = 6.5V

+5V REGULATOR OUTPUT

vs. TEMPERATURE

MAX16803 toc06

TEMPERATURE (°C)

5V REGULATOR OUTPUT (V)

1109580655035205-10-25

5.1

5.2

5.3

5.4

5.5

5.0

-40 125

I

LOAD

= 1mA

NO LOAD

I

LOAD

= 5mA

(V

CS+

- V

CS-

) vs. I

V5

MAX16803 toc07

IV5 (mA)

(V

CS+

- V

CS-

) (V)

764 52 31

0.199

0.200

0.201

0.202

0.203

0.204

0.205

0.206

0.207

0.208

0.209

0.210

0.198
08

I

LOAD

= 410mA

+5V REGULATOR OUTPUT vs. V

IN

MAX16803 toc08

V

IN

(V)

5V REGULATOR OUTPUT (V)

353025201510

5.15

5.20

5.25

5.30

5.10
540

LOAD = 1mA

NO LOAD

LOAD = 5mA

200Hz DIMMED OPERATION

MAX16803 toc09

20µs/div

V

DIM

2V/div

I

LOAD

200mA/div
0A

I

LOAD

= 350mA

V

IN

= VEN = 12V
DIM PULSED AT
200Hz (1%
DUTY CYCLE)

0V

200Hz DIMMED OPERATION (EXPANDED)

MAX16803 toc10

20µs/div

V

DIM

2V/div

I

LOAD

200mA/div
0A

I

LOAD

= 350mA

V

IN

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

0V

200Hz DIMMED OPERATION (EXPANDED)

MAX16803 toc11

20µs/div

V

DIM

2V/div

I

LOAD

200mA/div
0A

I

LOAD

= 350mA

V

IN

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

0V