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19-3803; Rev 0; 8/05
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 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 -40C to +125C temperature range.
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 (12A 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 -40C to +125C 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+ TEMP RANGE PINPACKAGE PKG CODE T1655-3 T1655-3
-40C to +125C 16 TQFN-EP* -40C to +125C 16 TQFN-EP*
+Denotes lead-free package. *EP = Exposed paddle.
Pin Configuration
GND CS+ V5 CS-
Simplified Diagram
TOP VIEW
12
11
10
9
+6.5V TO +40V IN 0.1F N.C. N.C. N.C. N.C. OUT +5V REG V5 0.1F LEDs
N.C. 13 N.C. 14 EN 15 OUT 16
8 7
MAX16800
CS+ PWM DIMMING EN CSGND RSENSE
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/Dallas 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 VIN = +16V) ........................................................60 minutes Maximum Current Into Any Pin (except VIN and OUT) .......20mA Continuous Power Dissipation (TA = +70C) 16-Pin TQFN 5mm x 5mm (derate 33.3mW/C above +70C)............................2666.7mW Operating Junction Temperature Range ...........-40C to +125C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
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
(VIN = +12V, EN = VIN, CV5 = 0.1F to GND, IV5 = 0, CS- = GND, connect RSENSE = 0.58 between CS+ and CS-. Connect OUT to CS+ (Note 1). TJ = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (Note 2)
PARAMETER Supply Voltage Range Ground Current Shutdown Supply Current Guaranteed Output Current Output Current Accuracy SYMBOL VIN IG ISHDN IOUT (Note 1) ILOAD = 350mA EN 0.6V RSENSE = 0.55 35mA < IOUT < 350mA IOUT = 350mA (current pulsed), 12V < VIN < 40V IOUT = 350mA (current pulsed), 6.5V < VIN < 40V Current rising Current falling VOUT = 0V, VIN = 12V IEN VIH VIL tON VRSNS EN rising edge to 90% of OUT VSENSE = VCS+ - VCSVCS+ = 220mV VCS+ = 220mV 197 -14 +84 0.6 135 204 350 211 400 350 3.5 0.5 0.5 5.4 90 600 800 100 2.8 1.2 1.5 CONDITIONS MIN 6.5 1.4 12 TYP MAX 40.0 3 40 UNITS V mA A mA % V V mA/s mA nA V V s mV A A
Dropout Voltage (Note 3)
VDO
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 RSENSE Voltage Input Current (CS+) Input Current (CS-)
2
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High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +12V, EN = VIN, CV5 = 0.1F to GND, IV5 = 0, CS- = GND, connect RSENSE = 0.58 between CS+ and CS-. Connect OUT to CS+ (Note 1). TJ = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (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 < ILOAD < 4mA (Note 5) V5 = 0V (Note 6) 5.0 5.27 15 30 5.5 60 V mA +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 TA = +25C. Limits over the operating temperature range are guaranteed by design. Note 3: Dropout is measured as follows: Connect RO = 27 from OUT to CS+. Connect RSENSE = 0.58 from CS+ to CS-. Set VIN = +12V (record VOUT as VOUT1). Reduce VIN until VOUT = 0.97 x VOUT1 (record as VIN2 and VOUT2). VDO = VIN2 - VOUT2. Note 4: IV5 = 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
(VIN = VEN = +12V, TA = +25C, unless otherwise noted.)
OUTPUT CURRENT vs. TEMPERATURE
MAX16800 toc01
(VCS+ - VCS-) 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 ILOAD = 35mA ILOAD = 100mA ILOAD = 200mA ILOAD = 350mA
0.210 0.209 0.208 (VCS+ - VCS-) (V) 0.207 0.206 0.205 0.204 0.203 0.202 0.201 0.200 VIN = 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)
(VIN = VEN = +12V, TA = +25C, 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 ILOAD = 350mA
35 30 SHUTDOWN CURRENT (A) 25 20 15 10 5 0 VIN = 6.5V VIN = 20V VIN = 12V VIN = 40V
5.5
5V REGULATOR OUTPUT (V)
5.4 ILOAD = 1mA 5.3 NO LOAD
5.2
5.1
ILOAD = 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)
(VCS+ - VCS-) vs. IV5
0.209 0.208 0.207 (VCS+ - VCS-) (V) 0.206 0.205 0.204 0.203 0.202 0.201 0.200 0.199 0.198 0 1 2 3 4 IV5 (mA) 5 6 7 8
MAX16800 toc07
+5V REGULATOR OUTPUT vs. VIN
NO LOAD 5V REGULATOR OUTPUT (V) 5.25
MAX16800 toc08
200Hz DIMMED OPERATION
MAX16800 toc09
0.210
5.30
VIN 5V/div 0V
ILOAD = 410mA
5.20
ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE) LOAD = 1mA LOAD = 5mA ILOAD 200mA/div
5.15
5.10 5 10 15 20 25 30 35 40 1ms/div VIN (V)
200Hz DIMMED OPERATION EXPANDED
MAX16800 toc10
200Hz DIMMED OPERATION EXPANDED
MAX16800 toc11
200Hz DIMMED OPERATION
MAX16800 toc12
VIN 5V/div 0V ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE) ILOAD 100mA/div ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE)
VIN 5V/div 0V ILOAD = 350mA, VIN = 12V, EN PULSED AT 200Hz (50% DUTY CYCLE)
EN 10V/div 0V
ILED 100mA/div
ILED 100mA/div 0 1ms/div
0
0
20s/div
4s/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+ CSV5 GND EN EP FUNCTION Current-Regulated Output. Connect pin 1 to pin 16. Positive Input Supply. Bypass IN with a 0.1F (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 0.1F 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 output 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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High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver MAX16800
power series pass device (see the Functional Diagram). The regulation point is factory set at (VCS+ VCS-) = 204mV 3.5%. The regulated current is user defined by the value of RSENSE. The MAX16800 is a current controller internally optimized for driving the impedance range expected from one or more HB LEDs. fier connected across RSENSE provides ground-loop immunity and low-frequency noise rejection. The LED current is given by the equation below: ILED = VSENSE / RSENSE
Input Voltage Considerations
For proper operation, the minimum input voltage must always be +1.2V (+1.5V for VIN <+12V) higher than the worst-case sum of all the forward drops of all seriesconnected LEDs to the output of the MAX16800. The minimum operating voltage of the device is +6.5V. The device will operate below +6.5V; however, output current may not meet the full regulation specification (see the Typical Operating Characteristics).
+5V Regulator
The MAX16800 includes a fixed +5V output regulator that delivers up to 4mA of load current for low-power applications throughout the +6.5V to +40V input voltage range. Connect a 0.1F compensation capacitor from V5 to ground. Shorting V5 to ground disables the thermal shutdown.
Low-Frequency PWM at the Output
The MAX16800 provides pulsed or chopped current dimming. Generally, high-brightness LEDs are binned to match at their full-rated current; however, LEDs from the same bin exhibit poor matching at currents other than full-rated current. To achieve uniformity, HB LED manufacturers recommend PWM pulsing of the LED current at their full-rated value. There are two methods for producing a PWM output. One method is by pulsing the enable input (EN) while having a constant voltage at IN. The other method is to connect EN to IN and pulse both EN and IN. Both methods generate a regulated-amplitude PWM current (variable duty cycle) that can provide control over the LED brightness (see Figures 1 and 2).
Thermal Protection
The MAX16800 enters a thermal-shutdown mode in the event of overheating. This typically occurs in overload or output short-circuit conditions. When the junction temperature exceeds TJ = +155C (typ), the internal thermal-protection circuitry turns off the series pass device. The MAX16800 recovers from thermal-shutdown mode once the junction temperature drops by 23C (typ). The part will therefore protect itself by thermally cycling in the event of a short-circuit or overload condition.
Applications Information
Programming the LED Current
The MAX16800 uses a sense resistor across CS+ and CS- to set the LED current. The differential sense ampli-
VEN
16 OUT 1 VIN C1 3 4 IN N.C. N.C. 5 2 OUT IN
15 EN
14 N.C.
13 N.C. GND 12 D1 V5 11 C2 CS- 10 CS+ 9 RSENSE ILED VIN C1 3 4 IN N.C. 1 2 OUT IN
16 OUT
15 EN
14 N.C.
13 N.C. GND 12 D1 V5 11 C2 CS- 10 CS+ 9 RSENSE ILED
MAX16800
MAX16800
N.C. 6
N.C. 7
N.C. 8
N.C. 5
N.C. 6
N.C. 7
N.C. 8
Figure 1. Pulse Application with VIN at a Constant Voltage
Figure 2. Pulse Application with EN Connected to VIN
6
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High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver
Typical Operating Circuit
PROCESS: BiCMOS
MAX16800
Chip Information
16 OUT 1 VIN C1 3 4 IN N.C. N.C. 5 2 OUT IN
15 EN
14 N.C.
13 N.C. GND 12 D1 V5 11 C2 CS- 10 CS+ 9 RSENSE
MAX16800
N.C. 6
N.C. 7
N.C. 8
_______________________________________________________________________________________
7
High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver MAX16800
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) QFN THIN.EPS
L
D2 D D/2 MARKING k L E/2 E2/2 E (NE-1) X e
C L C L
b D2/2
0.10 M C A B
XXXXX
E2
PIN # 1 I.D.
DETAIL A
e (ND-1) X e
e/2
PIN # 1 I.D. 0.35x45 DETAIL B
e
L1
L
C L
C L
L
e 0.10 C A 0.08 C
e
C
A1 A3 PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
-DRAWING NOT TO SCALE-
21-0140
H
1
2
8
_______________________________________________________________________________________
High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
MAX16800
COMMON DIMENSIONS
PKG. 16L 5x5 20L 5x5 28L 5x5 32L 5x5 40L 5x5 SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
EXPOSED PAD VARIATIONS PKG. CODES T1655-1 T1655-2 T1655N-1 T2055-2 T2055-3 T2055-4 T2055-5 T2855-1 T2855-2 T2855-3 T2855-4 T2855-5 T2855-6 T2855-7 T2855-8 T2855N-1 T3255-2 T3255-3 T3255-4 T3255N-1 T4055-1
D2
MIN. NOM. MAX. MIN.
E2
NOM. MAX.
L
0.15
A A1 A3 b D E e k L L1 N ND NE JEDEC
NOTES:
DOWN BONDS ALLOWED
0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0 0.02 0.05 0.20 REF. 0.25 0.30 0.35 4.90 5.00 5.10 4.90 5.00 5.10 0.80 BSC. 0.25 0 0.02 0.05 0 0.02 0.05 0 0.02 0.05 0 0.02 0.05 0.20 REF. 0.20 REF. 0.20 REF. 0.20 REF. 0.25 0.30 0.35 0.20 0.25 0.30 0.20 0.25 0.30 0.15 0.20 0.25 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 0.40 BSC. 0.65 BSC. 0.50 BSC. 0.50 BSC. - 0.25 - 0.25 - 0.25 0.35 0.45 0.25 -
3.00 3.00 3.00 3.00 3.00 3.00 3.15 3.15 2.60 3.15 2.60 2.60 3.15 2.60 3.15 3.15 3.00 3.00 3.00 3.00 3.20
3.10 3.20 3.00 3.10 3.20 3.00 3.10 3.20 3.00 3.10 3.20 3.00 3.10 3.20 3.00 3.10 3.20 3.00 3.25 3.25 2.70 3.25 2.70 2.70 3.25 2.70 3.25 3.25 3.10 3.10 3.10 3.10 3.35 3.35 2.80 3.35 2.80 2.80 3.35 2.80 3.35 3.35 3.20 3.20 3.20 3.20 3.15 3.15 2.60 3.15 2.60 2.60 3.15 2.60 3.15 3.15 3.00 3.00 3.00 3.00
3.10 3.10 3.10 3.10 3.10 3.10 3.25 3.25 2.70 3.25 2.70 2.70 3.25 2.70 3.25 3.25 3.10 3.10 3.10 3.10 3.30
3.20 3.20 3.20 3.20 3.20 3.20 3.35 3.35 2.80 3.35 2.80 2.80 3.35 2.80 3.35 3.35 3.20 3.20 3.20 3.20 3.40
** ** ** ** ** ** 0.40 ** ** ** ** ** ** ** 0.40 ** ** ** ** ** **
NO YES NO NO YES NO YES NO NO YES YES NO NO YES YES NO NO YES NO NO YES
0.30 0.40 0.50 0.45 0.55 0.65 0.45 0.55 0.65 0.30 0.40 0.50 0.40 0.50 0.60 - 0.30 0.40 0.50 16 4 4 WHHB 20 5 5 WHHC 28 7 7 WHHD-1 32 8 8 WHHD-2 40 10 10 -----
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994. 2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 3. N IS THE TOTAL NUMBER OF TERMINALS. 4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE. 5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm FROM TERMINAL TIP. 6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY. 7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION. 8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS. 9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT EXPOSED PAD DIMENSION FOR T2855-1, T2855-3, AND T2855-6. 10. WARPAGE SHALL NOT EXCEED 0.10 mm. 11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY. 12. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY. 13. LEAD CENTERLINES TO BE AT TRUE POSITION AS DEFINED BY BASIC DIMENSION "e", 0.05.
3.30 3.40 3.20
** SEE COMMON DIMENSIONS TABLE
PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
-DRAWING NOT TO SCALE-
21-0140
H
2
2
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 _____________________ 9 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
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