General Description
The MAX16815/MAX16828 current regulators operate
from a 6.5V to 40V input voltage range and deliver up
to 100mA (MAX16815) or 200mA (MAX16828) to high-
brightness LED (HB LED) loads. The output current is
adjusted by using an external current-sense resistor in
series with the LEDs. The MAX16815/MAX16828’s dim-
ming input allows wide-range “pulsed” PWM operation.
An on-board pass element minimizes external compo-
nents while providing ±3.5% output-current accuracy.
The MAX16815/MAX16828 are available in a thermally
enhanced, 3mm x 3mm, 6-pin TDFN package with
exposed pad and in an 8-pin SO package with
exposed pad; they are 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
Signage and Indicators
Ambient and Architectural Lighting
LED Bulbs
Display Backlighting
Features
o6.5V to 40V Operating Range
oAdjustable LED Current
MAX16815: 35mA to 100mA
MAX16828: 35mA to 200mA
o±3.5% LED Current Accuracy
oHigh-Voltage DIM Input for Dimming Interface
oIntegrated Pass Element with Low-Dropout
Voltage (0.4V typ)
o5V Regulated Output with 4mA Source Capability
oThermal Shutdown
oOutput Short-Circuit Protection
oAvailable in Small, Thermally Enhanced,
3mm x 3mm, 6-Pin TDFN and 8-Pin SO with
Exposed Pad Packages
o-40°C to +125°C Operating Temperature Range
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
________________________________________________________________
Maxim Integrated Products
1
Simplified Diagram
Ordering Information
MAX16815
MAX16828
IN OUT
V5 LEDs
RSENSE
0.1µF
6.5V TO 40V
+5V REG
CS+
0.1µF
GND
DIM
PWM
DIMMING
CS-
MAX16815
MAX16828
IN OUT
V5 LEDs
RSENSE
C1
+6.5V TO +40V
+5V REG
CS+
C2
CS-
DIM
PWM DIMMING
GND
EN
19-4032; Rev 1; 7/09
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.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX16815ATT+ -40°C to +125°C 6 TDFN-EP*
MAX16815ASA+ -40°C to +125°C 8 SO-EP*
MAX16828ATT+ -40°C to +125°C 6 TDFN-EP*
MAX16828ASA+ -40°C to +125°C 8 SO-EP*
Typical Operating Circuit
Pin Configurations appear at end of data sheet.
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = 12V, VEN = 12V (SO only), CV5 = 0.1µF to GND, IV5 = 0, VDIM = 4V, VCS- = 0V (SO only), connect RSENSE = 2Ω(MAX16815)
and RSENSE = 1Ω(MAX16828) between CS+ and GND. TA= -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 to GND ...............................................................-0.3V to +45V
CS+, CS-, V5 to GND ...............................................-0.3V to +6V
DIM, EN to GND...........................................-0.3V to (VIN + 0.3V)
OUT Short Circuited to GND Duration
(at VIN = +16V) .......................................................60 minutes
Maximum Current into Any Pin (except IN and OUT).......±20mA
Continuous Power Dissipation (TA= +70°C)
6-Pin, 3mm x 3mm TDFN
(derate 18.2mW/°C above +70°C)..........................1454.5mW
8-Pin SO (derate 23.3mW/°C above +70°C)...........1860.5mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Junction-to-Case Thermal Resistance (θJC) (Note 1)
6-Pin, 3mm x 3mm TDFN ...............................................9°C/W
8-Pin SO .........................................................................7°C/W
Junction-to-Ambient Thermal Resistance (θJA) (Note 1)
6-Pin, 3mm x 3mm TDFN .............................................42°C/W
8-Pin SO .......................................................................43°C/W
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage Range VIN (Note 3) 6.5 40.0 V
ILOAD = 100mA 0.82 2
Ground Current IGILOAD = 200mA 1 2 mA
Shutdown Supply Current ISHDN VEN ≤ 0.6V (SO only) 35 70 µA
RSENSE = 2_ (MAX16815) 100
Guaranteed Output Current IOUT RSENSE = 1_ (MAX16828) 200 mA
35mA < IOUT < 100mA (MAX16815) ±3.5
Output Current Accuracy 35mA < IOUT < 200mA (MAX16828) ±3.5 %
IOUT = 100mA (current pulsed),
12V < VIN < 40V (MAX16815) (Note 4) 0.1 0.4
IOUT = 100mA (current pulsed),
6.5V < VIN < 12V (MAX16815) (Note 4) 0.1 0.6
IOUT = 200mA (current pulsed),
12V < VIN < 40V (MAX16828) (Note 5) 0.27 0.55
Dropout Voltage ∆VDO
IOUT = 200mA (current pulsed),
6.5V < VIN < 12V (MAX16828) (Note 5) 0.27 0.7
V
Current rising 9.7
Output Current Slew Rate Current falling 9.7 mA/µs
VOUT = 0V, VIN = 12V, MAX16815 130 200 270
Short-Circuit Current VOUT = 0V, VIN = 12V, MAX16828 250 300 350 mA
EN INPUT (SO ONLY)
EN Input Current IEN -2.5 -1 -0.2 µA
EN Input Voltage High VIH 2.8 V
EN Input Voltage Low VIL 0.6 V
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.
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 12V, VEN = 12V (SO only), CV5 = 0.1µF to GND, IV5 = 0, VDIM = 4V, VCS- = 0V (SO only), connect RSENSE = 2Ω(MAX16815)
and RSENSE = 1Ω(MAX16828) between CS+ and GND. TA= -40°C to +125°C, unless otherwise noted. Typical values are at
TA= +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CURRENT SENSE
Regulated RSENSE Voltage VRSNS VRSNS = VCS+ for TDFN package;
VRSNS = VCS+ - VCS- for SO package 193 200 207 mV
CS- Voltage Range SO only -0.3 +4.7 V
Input Current (CS+) VCS+ = 220mV 2.7 7 µA
Input Current (CS-) VCS+ = 220mV (SO only) -50 17.2 µA
DIM Input Current VDIM = 0V -2.5 -1.0 -0.2 µA
DIM Input-Voltage High VIH 2.8 V
DIM Input-Voltage Low VIL 0.6 V
Turn-On Time tON After VDIM rising to 4V (Note 7) 100 µs
Turn-Off Time tOFF After VDIM falling to 0.6V (Note 7) 55 µs
THERMAL OVERLOAD
Thermal-Shutdown Temperature +159 °C
Thermal-Shutdown Hysteresis 24 °C
+5V REGULATOR
Output-Voltage Load Regulation VV5 (Note 8) 4.8 5.0 5.2 V
Output Voltage ∆VV5 0 < IV5 < 4mA 12 20 mV/mA
V5 Short-Circuit Current VV5 = 0 (Note 9) 15 mA
Note 2: All devices are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by
design.
Note 3: Resistors were added from OUT to CS+ to aid with power dissipation.
Note 4: Dropout is measured as follows:
Connect ROfrom OUT to CS+. Connect RSENSE = 2Ω(MAX16815) from CS+ to GND (for TDFN) or from CS+ to CS- (for
SO). Set VIN = 12V (record VOUT1 = VOUT). For VIN = 40V, use RO= 360Ω; for VIN = 6.5V, use RO= 56Ω.
Reduce VIN until VOUT = 0.97 x VOUT1 (record as VIN2 and VOUT2). ∆VDO = VIN2 - VOUT2.
Note 5: Dropout is measured as follows:
Connect ROfrom OUT to CS+. Connect RSENSE = 1Ω(MAX16828) from CS+ to GND (for TDFN) or from CS+ to CS- (for
SO). Set VIN = 12V (record VOUT1 = VOUT). For VIN = 40V, use RO= 180Ω; for VIN = 6.5V, use RO= 27Ω.
Reduce VIN until VOUT = 0.97 x VOUT1 (record as VIN2 and VOUT2). ∆VDO = VIN2 - VOUT2.
Note 6: IV5 = 0mA.
Note 7: tON time includes the delay and the rise time needed for IOUT to reach 90% of its final value. tOFF time is the time needed for
IOUT to drop below 10%. See the
Typical Operating Characteristics
. tON and tOFF are tested with 100Ω(MAX16815) or 51Ω
(MAX16828) from OUT to CS+.
Note 8: Current regulation varies with V5 load (see the
Typical Operating Characteristics
).
Note 9: Thermal shutdown does not function if V5 is shorted to ground.
Typical Operating Characteristics
(VIN = 12V, TA= +25°C, unless otherwise noted.)
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
4 _______________________________________________________________________________________
OUTPUT CURRENT
vs. TEMPERATURE
MAX16815 toc01
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
1109580655035205-10-25
50
100
150
200
250
300
0
-40 125
MAX16828 ILOAD = 200mA
MAX16815 ILOAD = 100mA
MAX16815 AND MAX16828 ILOAD = 35mA
VCS+ (FOR TDFN) OR VCS+ - VCS- (FOR SO)
vs. OUTPUT CURRENT
MAX16815 toc02
OUTPUT CURRENT (mA)
VCS+ (FOR TDFN) OR VCS+ - VCS- (FOR SO) (V)
959085807570656055504540
0.1
0.2
0.3
0.4
0
35 100
MAX16815 AND MAX16828
IOUT UP TO 100mA FOR MAX16828
DROPOUT VOLTAGE
vs. TEMPERATURE
MAX16815 toc04
TEMPERATURE (°C)
DROPOUT VOLTAGE (V)
1109580655035205-10-25
0.1
0.2
0.3
0.4
0.5
0
-40 125
MAX16828 ILOAD = 200mA
MAX16815 ILOAD = 100mA
+5V REGULATOR OUTPUT
vs. TEMPERATURE
MAX16815 toc05
TEMPERATURE (°C)
5V REGULATOR OUTPUT (V)
1109580655035205-10-25
4.9
5.0
5.1
5.2
4.8
-40 125
IV5 = 1mA
NO LOAD
IV5 = 5mA
MAX16815 AND MAX16828
OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX16815 toc03
INPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
353010 15 20 25
50
100
150
200
250
300
350
400
0
540
MAX16828
MAX16815
VCS+ (FOR TDFN) OR VCS+ - VCS- (FOR SO)
vs. IV5
MAX16815 toc06
VCS+ (FOR TDFN) OR VCS+ - VCS- (FOR SO) (V)
321
0.1
0.2
0.3
0.4
0
04
MAX16815 AND MAX16828
+5V REGULATOR OUTPUT vs. VIN
MAX16815 toc07
VIN (V)
5V REGULATOR OUTPUT (V)
353025201510
4.9
5.0
5.1
5.2
4.8
540
IV5 = 1mA NO LOAD
IV5 = 5mA
MAX16815 AND MAX16828
MAX16815 200Hz DIMMED OPERATION
MAX16815 toc08
1ms/div
0V
VDIM
10V/div
ILOAD
50mA/div
0
ILOAD = 100mA, VIN = 12V
DIM PULSED AT 200Hz
150% DUTY CYCLE
MAX16815 200Hz DIMMED OPERATION
(EXPANDED)
MAX16815 toc09
10µs/div
0V
VDIM
10V/div
ILOAD
50mA/div
0
ILOAD = 100mA, VIN = 12V
DIM PULSED AT 200Hz
150% DUTY CYCLE
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(VIN = 12V, TA= +25°C, unless otherwise noted.)
MAX16815 200Hz DIMMED OPERATION
(EXPANDED)
MAX16815 toc10
20µs/div
0V
VDIM
10V/div
ILOAD
50mA/div
0
ILOAD = 100mA, VIN = 12V
DIM PULSED AT 200Hz
50% DUTY CYCLE
MAX16828 200Hz DIMMED OPERATION
MAX16815 toc11
1ms/div
0V
VDIM
10V/div
ILOAD
200mA/div
0
ILOAD = 200mA, VIN = 12V
DIM PULSED AT 200Hz
50% DUTY CYCLE
MAX16828 200Hz DIMMED OPERATION
(EXPANDED)
MAX16815 toc12
20µs/div
0V
VDIM
10V/div
ILOAD
200mA/div
0
ILOAD = 200mA, VIN = 12V
DIM PULSED AT 200Hz
50% DUTY CYCLE
MAX16828 200Hz DIMMED OPERATION
(EXPANDED)
MAX16815 toc13
20µs/div
0V
VDIM
10V/div
ILOAD
200mA/div
0
ILOAD = 200mA, VIN = 12V
DIM PULSED AT 200Hz
50% DUTY CYCLE
TDFN Functional Diagram
BANDGAP
AND 5V
REGULATOR
THERMAL
SHUTDOWN
GND
V5
1.2V
DIM IN
P
OUT
CS+
0.8µA
MAX16815
MAX16828
IREG
DIFF
AMP
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
6 _______________________________________________________________________________________
Pin Description
PIN
TDFN SO
NAME FUNCTION
1 6 DIM
Pulsed Dimming Input. Drive DIM low to turn off output current (LED current). Drive DIM
high to turn on the output current (LED current). DIM is pulled high to VIN when left
unconnected.
— 7 EN
Enable Input. Drive EN high to enable the output. For the TDFN package, this input is not
accessible and always high.
2 8 OUT Current-Regulated Output
3 1 IN Positive Input Supply. Bypass IN with a 0.1µF (min) capacitor to GND.
4 2 CS+
LED Current-Sense Amplifier Positive Input. For the SO package version, connect the
current-sense resistor between this pin and CS-; for the TDFN version, connect it between
this pin and ground.
— 3 CS- LED Current-Sense Amplifier Negative Input. Connect to ground.
5 4 V5 +5V Regulated Output. Connect a 0.1µF (min) capacitor from V5 to GND.
6 5 GND Ground
— — EP
Exposed Pad. Connect to a large ground plane for effective power dissipation. Do not use
as the only ground connection.
MAX16815/MAX16828
Detailed Description
+5V Regulator
The MAX16815/MAX16828 include a fixed +5V output
regulator that delivers up to 4mA of load current
throughout the 6.5V to 40V input voltage range.
Connect a 0.1µF compensation capacitor from V5 to
ground. Shorting V5 to ground disables the thermal
shutdown. V5 stays on during PWM dimming.
Thermal Protection
The MAX16815/MAX16828 enter a thermal-shutdown
mode in the event of overheating. This typically occurs
in overload or output short-circuit conditions. If the
junction temperature exceeds TJ= +159°C (typ), the
internal thermal-protection circuitry turns off the series
pass device. The MAX16815/MAX16828 recover from
thermal-shutdown mode once the junction temperature
drops by 24°C (typ). The devices therefore protect
themselves by thermal cycling in the event of a short-
circuit or overload condition. Shorting V5 to ground dis-
ables the thermal shutdown.
Applications Information
Programming the LED Current
The MAX16815/MAX16828 use a sense resistor across
CS+ and GND for the TDFN package or across CS+
and CS- for the SO package, to set the LED current.
The LED current is given by ILED = VRSNS/RSENSE.
Input-Voltage Considerations
For proper operation, the minimum input voltage must
always be:
VIN(MIN) ≥VRSNS(MAX) + VFT(MAX) + ∆VDO(MAX)
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
)
and the V5 regulator will drop below 5V.
Low-Frequency PWM Dimming
at the Output
Provide a pulse to the dimming input (DIM) of the
MAX16815/MAX16828 to produce a PWM output.
Alternatively, connect DIM to IN and pulse IN.
SO Functional Diagram
BANDGAP
AND 5V
REGULATOR
THERMAL
SHUTDOWN
GND
1.2V
DIM IN
P
OUT
CS+
CS-
0.8µA
MAX16815
MAX16828
V5
EN
IREG
DIFF
AMP
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
_______________________________________________________________________________________ 7
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
8 _______________________________________________________________________________________
Two Brightness Levels for
TAIL/STOP Lights
Figure 1 shows PWM dimming operation for the
MAX16815/MAX16828 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. The PWM dimming operation is dis-
abled and the LEDs light up to full brightness. See the
ICM7555 data sheet for formulas to calculate the dim-
ming frequency and the duty cycle.
LED Current Thermal Foldback
With a minimum number of external components, the
MAX16815/MAX16828 provide LED current thermal
foldback using a negative temperature coefficient
(NTC) thermistor. Figure 2 shows a thermistor connect-
ed to V5 and the CS+ of the MAX16815/MAX16828. As
the temperature increases, the voltage drop across R2
increases, causing the LED current to decrease.
ILED = [VRSNS - (R2 / RT) (VV5 - VRSNS)]/R1
Other Applications
The application circuit in Figure 3 implements a two-
level brightness current for TAIL/STOP lights. In TAIL
operation, Q1 is off and R1 sets the output current. In
STOP operation, Q1 turns on and the output current is
set by a parallel combination of R1 and R2. Figure 4
shows an application circuit with the MAX16815/
MAX16828 using a single BJT to provide high output
current. For proper operation:
VIN(MIN) > VCESAT(MAX) + VFT(MAX) + VRSNS
where VCESAT(MAX) is the maximum saturation voltage
of the external BJT and VFT(MAX) is the total forward
voltage of all series connected LEDs.
IN
DIM CS+
V5
OUT
GND
+5V REG LEDs
C2
TH
TRG GND
OUT
IN
DIS
ICM7555
R3
C2
R2
R1
C1
D3
D4
D1
TAIL
STOP
D2
RSENSE
R4*
*R4 < 300kΩ
MAX16815
MAX16828
CS-
VIN IN
DIM
PWM
DIMMING
CS+
V5
OUT
GND
LEDs
C2
C1
R1
R2
RT
MAX16815
MAX16828
CS-
Figure 1. PWM Dimming Operation with ICM7555 Timer
Figure 2. LED Current Thermal Foldback with an NTC
Thermistor
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
_______________________________________________________________________________________ 9
Multichannel HB LED Driver
Figure 5 shows an array of MAX16815/MAX16828s with
independent DIM control. The MAX5094C, a current-
mode PWM controller, provides the input power to each
LED driver preregulated voltage to multiple MAX16815/
MAX16828 drivers.
Chip Information
PROCESS: BiCMOS
IN
CS+
V5
DIM
OUT
GND
LEDs
C2
R1
Z1
R2
C1
D1
TAIL
STOP
R3
MAX16815
MAX16828
CS-
Q1
Figure 3. Two-Level Brightness with Current Level Switch for
TAIL/STOP Lights
VIN IN
DIM
PWM
DIMMING
CS+
V5
OUT
GND
LEDs
C2
Q1
C1
RSENSE
MAX16815
MAX16828
CS-
Figure 4. Increased LED Current (Ampere Range)
with a Single BJT
REF C3
R3
C6
R4
C4
L1
COMP
FB
CS
GND
VCC
VIN
CT/RT
CT
OUT
MAX5094C
MAX16815
MAX16828
U2
CREF
C2
D1
CCOMP
RCOMP
IN
EN
DIM
R2
CS-
CS+
OUT
GND
V5
R5
C7
LEDs
Q1
C10
MAX16815
MAX16828
U4
IN
EN
DIM
CS-
CS+
OUT
GND
V5
R7
C11
LEDs
C8
MAX16815
MAX16828
U3
IN
EN
DIM
CS-
CS+
OUT
GND
V5
R6
C9
LEDs
Figure 5. Multichannel HB LED Drivers for LCD Backlight
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
10 ______________________________________________________________________________________
Pin Configurations
DIM
GNDV5
1
2
8
7
OUT
ENCS+
CS-
IN
SO
3
4
6
5
1
EP*
EP*
*EP = EXPOSED PAD
+
23
654
IN
OUT
DIM
CS+
V5
GND
MAX16815
MAX16828
MAX16815
MAX16828
TDFN
TOP VIEW
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
8 SO-EP S8E-12 21-0111
6 TDFN-EP T633-2 21-0137
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
MAX16815/MAX16828
High-Voltage, 100mA/200mA Adjustable Linear
High-Brightness LED Drivers with PWM Dimming
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
11
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 2/08 Initial release —
1 7/09
Added the SO package to the Ordering Information table, Electrical
Characteristics,TOC 2 and TOC 6,Pin Description table, and Functional
Diagrams; modified the Simplified Diagram and Figures 1–4 to include the CS-
pin; and added the SO-EP Pin Configuration
1–4, 6–10
