19-3803; Rev 1; 4/09
High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver
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 dif-
ferential 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 ele-
ment 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.
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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
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
Ordering Information
PART
MAX16800ATE+
MAX16800ATE/V+
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
16 TQFN-EP*
16 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed paddle.
/V denotes an automotive qualified part.
Pin Configuration
GND
CS+
CS-
Simplified Diagram
+6.5V TO +40V
IN
0.1μF
OUT
+5V REG
V5
0.1μF
LEDs
TOP VIEW
12
11
V5
10
9
N.C. 13
N.C. 14
EN 15
OUT 16
8
7
N.C.
N.C.
N.C.
N.C.
PWM DIMMING
EN
MAX16800
CS+
R
SENSE
CS-
GND
MAX16800
6
5
+
1
OUT
2
IN
3
IN
4
N.C.
TQFN
________________________________________________________________
Maxim Integrated Products
1
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.
High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver
MAX16800
ABSOLUTE MAXIMUM RATINGS
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
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= +12V, EN = V
IN
, C
V5
= 0.1µF to GND, I
V5
= 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 T
A
= +25°C.) (Note 2)
PARAMETER
Supply Voltage Range
Ground Current
Shutdown Supply Current
Guaranteed Output Current
Output Current Accuracy
SYMBOL
V
IN
I
G
I
SHDN
I
OUT
(Note 1)
I
LOAD
= 350mA
V
EN
0.6V
350
±3.5
0.5
0.5
5.4
90
400
600
800
100
2.8
0.6
EN rising edge to 90% of OUT
V
SENSE
= V
CS+
- V
CS-
V
CS+
= 220mV
V
CS+
= 220mV
197
-14
+84
135
204
350
211
1.2
1.5
R
SENSE
= 0.55
35mA < I
OUT
< 350mA
I
OUT
= 350mA (current pulsed),
12V < V
IN
< 40V
I
OUT
= 350mA (current pulsed),
6.5V < V
IN
< 40V
Output Current Slew Rate
Short-Circuit Current
LOGIC INPUT
EN Input Current
EN Input Voltage High
EN Input Voltage Low
Turn–On Time
CURRENT SENSE (Note 4)
Regulated R
SENSE
Voltage
Input Current (CS+)
Input Current (CS-)
V
RSNS
mV
μA
μA
I
EN
V
IH
V
IL
t
ON
nA
V
V
μs
Current rising
Current falling
V
OUT
= 0V, V
IN
= 12V
CONDITIONS
MIN
6.5
1.4
12
TYP
MAX
40.0
3
40
UNITS
V
mA
μA
mA
%
V
V
mA/μs
mA
Dropout Voltage (Note 3)
VDO
2
_______________________________________________________________________________________
High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V, EN = V
IN
, C
V5
= 0.1µF to GND, I
V5
= 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 T
A
= +25°C.) (Note 2)
PARAMETER
THERMAL OVERLOAD
Thermal-Shutdown Temperature
Thermal-Shutdown Hysteresis
+5V REGULATOR
Output Voltage Regulation
Output Voltage Change
V5 Short-Circuit Current
V5
V5
0 < I
LOAD
< 4mA (Note 5)
V5 = 0V (Note 6)
5.0
5.27
15
30
5.5
60
mA
V
+155
23
°C
°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX16800
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 V
IN
= +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
).
ΔV
DO
= 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.
Typical Operating Characteristics
(V
IN
= V
EN
= +12V, T
A
= +25°C, unless otherwise noted.)
OUTPUT CURRENT
vs. TEMPERATURE
MAX16800 toc01
(V
CS+
- V
CS-
) vs. OUTPUT CURRENT
MAX16800 toc02
OUTPUT CURRENT
vs. INPUT VOLTAGE
350
OUTPUT CURRENT (mA)
300
250
200
150
100
50
0
MAX16800 toc03
450
400
OUTPUT CURRENT (mA)
350
300
250
200
150
100
50
0
I
LOAD
= 35mA
I
LOAD
= 100mA
I
LOAD
= 200mA
I
LOAD
= 350mA
0.210
0.209
0.208
(V
CS+
- V
CS-
) (V)
0.207
0.206
0.205
0.204
0.203
0.202
0.201
0.200
V
IN
= 12V
400
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
20 50 80 110 140 170 200 230 260 290 320 350
OUTPUT CURRENT (mA)
0
5
10
15
20
25
30
35
40
INPUT VOLTAGE (V)
_______________________________________________________________________________________
3
High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver
MAX16800
Typical Operating Characteristics (continued)
(V
IN
= V
EN
= +12V, T
A
= +25°C, unless otherwise noted.)
DROPOUT VOLTAGE
vs. TEMPERATURE
MAX16800 toc04
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX16800 toc05
+5V REGULATOR OUTPUT
vs. TEMPERATURE
MAX16800 toc06
1.0
0.9
0.8
DROPOUT VOLTAGE (V)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
I
LOAD
= 350mA
35
30
SHUTDOWN CURRENT (μA)
25
20
15
10
5
0
V
IN
= 6.5V
V
IN
= 20V
V
IN
= 12V
V
IN
= 40V
5.5
5V REGULATOR OUTPUT (V)
5.4
I
LOAD
= 1mA
5.3
NO LOAD
5.2
5.1
I
LOAD
= 5mA
5.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
(V
CS+
- V
CS-
) vs. I
V5
MAX16800 toc07
+5V REGULATOR OUTPUT vs. V
IN
NO LOAD
5V REGULATOR OUTPUT (V)
5.25
MAX16800 toc08
200Hz DIMMED OPERATION
MAX16800 toc09
0.210
0.209
0.208
0.207
(V
CS+
- V
CS-
) (V)
0.206
0.205
0.204
0.203
0.202
0.201
0.200
0.199
0.198
0
1
2
3
4
I
V5
(mA)
5
6
7
8
5.30
V
IN
5V/div
0V
I
LOAD
= 410mA
5.20
I
LOAD
= 350mA, V
IN
= V
EN
,
V
IN
PULSED AT 200Hz (50% DUTY CYCLE)
LOAD = 1mA
LOAD = 5mA
I
LOAD
200mA/div
5.15
5.10
5
10
15
20
25
30
35
40
1ms/div
V
IN
(V)
200Hz DIMMED OPERATION EXPANDED
MAX16800 toc10
200Hz DIMMED OPERATION EXPANDED
MAX16800 toc11
200Hz DIMMED OPERATION
MAX16800 toc12
V
IN
5V/div
0V
I
LOAD
= 350mA,
V
IN
= V
EN
,
V
IN
PULSED AT 200Hz
(50% DUTY CYCLE)
I
LOAD
100mA/div
I
LOAD
= 350mA,
V
IN
= V
EN
,
V
IN
PULSED AT 200Hz
(50% DUTY CYCLE)
V
IN
5V/div
0V
I
LOAD
= 350mA, V
IN
= 12V,
EN PULSED AT 200Hz (50% DUTY CYCLE)
EN
10V/div
0V
I
LED
100mA/div
I
LED
100mA/div
0
1ms/div
0
0
20μs/div
4μs/div
4
_______________________________________________________________________________________
High-Voltage, 350mA, Adjustable Linear
High-Brightness LED (HB LED) Driver
Pin Description
PIN
1, 16
2, 3
4–8, 13, 14
9
10
11
12
15
—
NAME
OUT
IN
N.C.
CS+
CS-
V5
GND
EN
EP
FUNCTION
Current-Regulated Output. Connect pin 1 to pin 16.
Positive Input Supply. Bypass IN with a 0.1µF (min) capacitor to GND. Connect pin 2 to pin 3.
Not Internally Connected
Positive Input of the Internal Differential Amplifier. Connect the current-sense resistor between CS+
and CS- to program the output current level.
Negative Input of the Internal Differential Amplifier. Connect the current-sense resistor between
CS- and CS+ to program the output current level.
+5V Regulated Output. Connect a 0.1µF capacitor from V5 to GND.
Ground
Enable Input. Drive EN high to enable the output.
Exposed Pad. Connect to the ground plane for effective power dissipation. Do not use as the only
ground connection.
MAX16800
Functional Diagram
IN
V5
REGULATOR
IN
EN
ENABLE
REFERENCE
GENERATOR
I_
REQ
OUT
DIFFERENTIAL
SENSE
AMPLIFIER
THERMAL
SHUTDOWN
CS+
CS-
MAX16800
Detailed Description
The MAX16800 is a high-current regulator capable of
providing up to a total of 350mA of current to one or
more strings of high-brightness LEDs. A wide operating
input voltage range of +6.5V to +40V makes the
MAX16800 ideal for automotive applications. A +5V
regulated output provides up to 4mA of current to
power external circuitry. In addition, the MAX16800 fea-
tures thermal and output short-circuit protection. The
wide operating voltage range helps protect the
MAX16800 against large transients such as those
found in load-dump situations up to 40V.
The MAX16800 uses a feedback loop to control the out-
put current. The differential voltage across the sense
resistor is compared to a fixed reference voltage, and
the error is amplified to serve as the drive to the internal
5
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