Datasheet

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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 wide-

range “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 compo-

nents 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

N.C.

OUT

CS+

GND

N.C.

12 11 9

OUT

N.C.

MAX16803

IN CS-

DIM

TQFN

TOP VIEW

Pin Configuration

Ordering Information

MAX16803

OUT

LEDs

SENSE

0.1µF

+6.5V TO +40V

+5V REG

CS+

0.1µF

CS-

DIM

PWM DIMMING

GND

Simplified Diagram

19-0532; Rev 1; 4/09

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.

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

EP = Exposed pad.

/V denotes an automotive qualified part.

PART TEMP RANGE PIN-PACKAGE

MAX16803ATE+ -40°C to +125°C 16 TQFN-EP*

MAX16803ATE/V+ -40°C to +125°C 16 TQFN-EP*

EVALUATION KIT

AVAILABLE

Summary of content (11 pages)

PAGE 1
9-0532; Rev 1; 4/09 KIT ATION EVALU E L B AVAILA High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator 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.
PAGE 2
MAX16803 High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator ABSOLUTE MAXIMUM RATINGS 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 VIN = +16V) ........................................................60 minutes Maximum Current Into Any Pin (except IN and OUT).........
PAGE 3
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator (VIN = VEN = +12V, CV5 = 0.1µF to GND, IV5 = 0, VCS- = 0V, VDIM = +4V, connect RSENSE = 0.58Ω between CS+ and CS- (Note 1). TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
Typical Operating Characteristics (continued) (VIN = VEN = +12V, TA = +25°C, unless otherwise noted.) ILOAD = 350mA 0.5 0.4 0.3 25 20 VIN = 20V 15 VIN = 12V 10 0.2 0 5.4 ILOAD = 1mA 5.2 ILOAD = 5mA 5.0 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) +5V REGULATOR OUTPUT vs. VIN 200Hz DIMMED OPERATION (VCS+ - VCS-) vs. IV5 0.209 0.208 0.207 0.206 0.205 0.204 0.
PAGE 5
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator VSNSE vs. VCS- IDIM vs. VDIM 204 MAX16803 toc13 300 MAX16803 toc12 205 250 IDIM (µA) VSNSE (mV) 200 203 202 150 100 201 50 VIN = 12V ILOAD = 350mA 200 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 2 VCS- (V) 4 6 8 10 12 14 16 VDIM (V) Pin Description PIN NAME FUNCTION 1, 16 OUT 2, 3 IN 4–8, 14 N.C. Not Internally Connected 9 CS+ Positive Input of the Internal Differential Amplifier.
PAGE 6
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator MAX16803 Functional Diagram V5 IN DIM REGULATOR IN EN ENABLE REFERENCE GENERATOR I_REG OUT CS+ DIFFERENTIAL SENSE AMPLIFIER MAX16803 CS- THERMAL SHUTDOWN Detailed Description The MAX16803 is a high-current regulator capable of providing up to a total of 350mA of current to one or more strings of HB LEDs. A wide operating input voltage range of +6.5V to +40V makes the MAX16803 ideal for automotive applications.
PAGE 7
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator where VFT(MAX) is the total forward voltage of all series connected LEDs. The minimum operating voltage of the device is +6.5V. The device operates below +6.5V; however, output current may not meet the full regulation specification (see the Typical Operating Characteristics).
PAGE 8
MAX16803 High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator Two Brightness Levels for TAIL/STOP Lights Figure 4 shows PWM dimming operation for the MAX16803 with an ICM7555 timer. The ICM7555 provides adjustable duty cycle using two external resistors and a capacitor. In TAIL operation, the output of the ICM7555 feeds into DIM and lights up the LEDs. The LED’s brightness depends on the duty cycle of the ICM7555. When VSTOP is present, DIM is pulled up to VSTOP.
PAGE 9
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator Figure 7 shows an application circuit with the MAX16803 using a single BJT to provide high output current. For proper operation: VIN(MIN) > VCESAT(MAX) + VFT(MAX) + VRSENSE where VCESAT(MAX) is the maximum saturation voltage of the external BJT. STOP TAIL IN OUT EN V5 C2 MAX16803 V5 LEDs C1 DIM CS+ R2 R1 Q1 CS- GND Figure 6.
PAGE 10
MAX16803 High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator Multichannel HB LED Driver Figure 8 shows an array of MAX16803s with independent DIM control. The MAX5094C, a current-mode PWM controller, provides the input power to each LED driver preregulated voltage to multiple MAX16803 drivers.
PAGE 11
High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator REVISION NUMBER REVISION DATE 0 5/06 Initial release 1 4/09 Updated Ordering Information table and added Package Information table. DESCRIPTION PAGES CHANGED — 1, 10 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.