Rainbow Electronics MAX16800 User Manual

General Description

The MAX16800 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.
The output current of the MAX16800 is adjusted by
using an external current-sense resistor in series with
the LEDs. An enable input allows wide-range “pulsed”
dimming. Wave-shaping circuitry reduces EMI. The dif­ferential current-sense input increases noise immunity.
The MAX16800 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 MAX16800 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: Tail Lights and CHMSL

Warning Lights for Emergency Vehicles

Navigation and Marine Indicators

General Illumination

Signage, Gasoline Canopies, Beacons

Features

♦ +6.5V to +40V Operating Range
♦ Adjustable Level (35mA to 350mA)
♦ ±3.5% Output Current Accuracy
♦ Integrated Pass Element with Low-Dropout

Voltage (0.5V typ)

♦ Output Short-Circuit Protection
♦ +5V Regulated Output with 4mA Source

Capability

♦ Thermal Shutdown
♦ Differential LED Current Sense
♦ High-Voltage Enable Pin for Dimming Interface
♦ Low Shutdown Supply Current (12µA typ)
♦ Low 204mV Current-Sense Reference Reduces

Power Losses

♦ Wave-Shaped Soft Edges Reduce Radiated EMI

During PWM Dimming

♦ Available in Small, Thermally Enhanced,

5mm x 5mm, 16-Pin TQFN Package

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

MAX16800

High-Voltage, 350mA, Adjustable Linear

High-Brightness LED (HB LED) Driver

________________________________________________________________ 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.

MAX16800

IN CS-

3

10

N.C.

TQFN

TOP VIEW

Pin Configuration

Ordering Information

MAX16800

IN

OUT

V5

LEDs

R

SENSE

0.1µF

+6.5V TO +40V

+5V REG

CS+

0.1µF

CS-

EN

PWM DIMMING

GND

Simplified Diagram

19-3803; Rev 0; 8/05

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 paddle.

PART

TEMP RANGE

PIN-

PKG

CODE

MAX16800ATE

T1655-3

MAX16800ATE+

T1655-3

PACKAGE

-40°C to +125°C 16 TQFN-EP*

-40°C to +125°C 16 TQFN-EP*

MAX16800

High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +12V, EN = VIN, CV5= 0.1µF to GND, IV5= 0, CS- = GND, connect R

SENSE

= 0.58Ω between CS+ and CS-. Connect OUT to

CS+ (Note 1). T

J

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

IN, OUT, and EN to GND........................................-0.3V to +45V

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

CS- to GND............................................................-0.3V to +0.3V

OUT Short Circuited to GND Duration

(at V

IN

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

Maximum Current Into Any Pin (except V

IN

and OUT) .......±20mA

Continuous Power Dissipation (T

A

= +70°C)
16-Pin TQFN 5mm x 5mm
(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

CONDITIONS

UNITS

Supply Voltage Range V

IN

(Note 1) 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 V

Dropout Voltage (Note 3) ∆VDO

I

OUT

= 350mA (current pulsed),

6.5V < V

IN

< 40V

0.5 1.5 V

Current rising 5.4

Output Current Slew Rate

Current falling 90

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

µs

CURRENT SENSE (Note 4)

Regulated R

SENSE

Voltage V

RSNS

V

SENSE

= V

CS+

- V

CS-

mV

Input Current (CS+) V

CS+

= 220mV -14 µA

Input Current (CS-) V

CS+

= 220mV

µA

SYMBOL

MIN TYP MAX

40.0

350

±3.5

400 600 800

135 350

197 204 211

100

+84

MAX16800

High-Voltage, 350mA, Adjustable Linear

High-Brightness LED (HB LED) Driver

_______________________________________________________________________________________ 3

Note 1: Resistors were added from OUT to CS+ to aid with the power dissipation during testing.
Note 2: All devices 100% production tested at T

A

= +25°C. Limits over the operating temperature range are guaranteed by design.

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 V

IN

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

ELECTRICAL CHARACTERISTICS (continued)

(VIN= +12V, EN = VIN, CV5= 0.1µF to GND, IV5= 0, CS- = GND, connect R

SENSE

= 0.58Ω between CS+ and CS-. Connect OUT to

CS+ (Note 1). T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

THERMAL OVERLOAD

Thermal-Shutdown Temperature

°C

Thermal-Shutdown Hysteresis 23 °C

+5V REGULATOR

Output Voltage Regulation V5 5.0

5.5 V

Output Voltage Change ∆V5 0 < I

LOAD

< 4mA (Note 5) 15 60 Ω

V5 Short-Circuit Current V5 = 0V (Note 6) 30 mA

Typical Operating Characteristics

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

OUTPUT CURRENT
vs. TEMPERATURE

MAX16800 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

MAX16800 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

MAX16800 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