© Semiconductor Components Industries, LLC, 2011
November, 2011 − Rev. 7
1Publication Order Number:
NUD4001/D
NUD4001, NSVD4001
High Current LED Driver
This device is designed to replace discrete solutions for driving
LEDs in low voltage AC−DC applications 5.0 V, 12 V or 24 V. An
external resistor allows the circuit designer to set the drive current for
different LED arrays. This discrete integration technology eliminates
individual components by combining them into a single package,
which results in a significant reduction of both system cost and board
space. The device is a small surface mount package (SO–8).
Features
•Supplies Constant LED Current for Varying Input Voltages
•External Resistor Allows Designer to Set Current – up to 500 mA
•Offered in Surface Mount Package Technology (SO−8)
•AEC−Q101 Qualified and PPAP Capable
•NSV Prefix for Automotive and Other Applications Requiring
Unique Site and Control Change Requirements
•Pb−Free Package is Available
Benefits
•Maintains a Constant Light Output During Battery Drain
•One Device can be used for Many Different LED Products
•Reduces Board Space and Component Count
•Simplifies Circuit and System Designs
Typical Applications
•Portables: For Battery Back−up Applications, also Simple Ni−CAD
Battery Charging
•Industrial: Low Voltage Lighting Applications and Small Appliances
•Automotive: Tail Lights, Directional Lights, Back−up Light,
Dome Light
PIN FUNCTION DESCRIPTION
Pin Symbol Description
1 Vin Positive input voltage to the device
2 Boost This pin may be used to drive an external transistor
as described in the App Note AND8198/D.
3 Rext An external resistor between Rext and Vin pins sets
different current levels for different application needs
4 GND Ground
5, 6, 7, 8 Iout The LEDs are connected from these pins to ground
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Device Package Shipping†
ORDERING INFORMATION
NUD4001DR2 SO−8 2500 / Tape & Reel
SO−8
CASE 751
STYLE 25
PIN CONFIGURATION
AND SCHEMATIC
1
8
Rext
GND
Vin
Iout
Iout
Iout
Current
Set Point
4001 = Specific Device Code
A = Assembly Location
Y = Year
WW = Work Week
G= Pb−Free Device
MARKING
DIAGRAM
Boost Iout
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
1
2
3
4
8
7
6
5
NUD4001DR2G SO−8
(Pb−Free)
2500 / Tape & Reel
4001
AYWW
G
1
8
NSVD4001DR2G SO−8
(Pb−Free)
2500 / Tape & Reel
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2
MAXIMUM RATINGS (TA = 25°C unless otherwise noted)
Rating Symbol Value Unit
Continuous Input Voltage Vin 30 V
Non−repetitive Peak Input Voltage (t v 1.0 ms) Vp60 V
Output Current
(For Vdrop ≤ 2.2 V) (Note 1)
Iout 500 mA
Output Voltage Vout 28 V
Human Body Model (HBM) ESD 1000 V
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. Vdrop = Vin – 0.7 V − VLEDs.
THERMAL CHARACTERISTICS
Characteristic Symbol Value Unit
Operating Ambient Temperature TA−40 to +125 °C
Maximum Junction Temperature TJ150 °C
Storage Temperature TSTG −55 to +150 °C
Total Power Dissipation (Note 2)
Derating above 25°C (Figure 3)
PD1.13
9.0
W
mW/°C
Thermal Resistance, Junction–to–Ambient (Note 2) RqJA 110 °C/W
Thermal Resistance, Junction–to–Lead (Note 2) RqJL 77 °C/W
2. Mounted on FR−4 board, 2 in sq pad, 2 oz coverage.
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
Output Current1
(Vin = 12 V, Rext = 2.0 W, VLEDs = 10 V)
Iout1 305 325 345 mA
Output Current2
(Vin = 30 V, Rext = 7.0 W, VLEDs = 24 V)
Iout2 95 105 115 mA
Bias Current
(Vin = 12 V, Rext = Open, VLEDs = 10 V)
IBias −5.0 8.0 mA
Voltage Overhead (Note 3) Vover 1.4 −−V
3. Vover = Vin – VLEDs.
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TYPICAL PERFORMANCE CURVES
(TA = 25°C unless otherwise noted)
Rext, W
IOUT (mA)
Figure 1. Output Current (IOUT)
vs. External Resistor (Rext)
1
10
100
1000
1 10 1000
100
PD, POWER DISSIPATION (W)
TA, AMBIENT TEMPERATURE (°C)
0.000
0.200
0.400
0.600
0.800
1.000
1.200
25 35 45 55 65 75 85 95 105 115 125
0.6
−40 −10 20 50 80 110 155
TJ, JUNCTION TEMPERATURE (°C)
Figure 2. Vsense vs. Junction Temperature
Vsense (V)
Figure 3. Total Power Dissipation (PD)
vs. Ambient Temperature (TA)
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
05
10 15 20 25 30
PD_control (W)
Vin (V)
Figure 4. Internal Circuit Power Dissipation
vs. Input Voltage
Figure 5. Current Regulation vs. Junction
Temperature
0.5
0.4
0.3
0.2
0.1
0.0
0.9
0.8
0.7
−25 5 35 65 95 125 140
1.2
−40 −10 20 50 80 110 155
TJ, JUNCTION TEMPERATURE (°C)
OUTPUT CURRENT, NORMALIZED
1.0
0.8
0.6
0.4
0.2
0.0
−25 5 35 65 95 125 140
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APPLICATION INFORMATION
Design Guide
1. Define LED’s current:
a. ILED = 350 mA
2. Calculate Resistor Value for Rext:
a. Rext = Vsense (see Figure 2) / ILED
b. Rext = 0.7 (TJ = 25 °C)/ 0.350 = 2.0 W
3. Define Vin:
a. Per example in Figure 6, Vin = 12 V
4. Define VLED @ ILED per LED supplier’s data
sheet:
a. Per example in Figure 6,
VLED = 3.5 V + 3.5 V + 3.5 V = 10.5 V
Figure 6. 12 V Application
(Series LED’s Array)
Rext
GND
Vin Iout
Current
Set Point
NUD4001
Boost Iout
12 V
Iout
Iout
1
2
3
4
8
7
6
5
5. Calculate Vdrop across the NUD4001 device:
a. Vdrop = Vin – Vsense – VLED
b. Vdrop = 12 V – 0.7 V (TJ = 25 °C) – 10.5 V
c. Vdrop = 0.8 V
6. Calculate Power Dissipation on the NUD4001
device’s driver:
a. PD_driver = Vdrop * Iout
b. PD_driver = 0.8 V x 0.350 A
c. PD_driver = 0.280 Watts
7. Establish Power Dissipation on the NUD4001
device’s control circuit per Figure 4:
a. PD_control = Figure 4, for 12 V input voltage
b. PD_control = 0.055 W
8. Calculate Total Power Dissipation on the device:
a. PD_total = PD_driver + PD_control
b. PD_total = 0.280 W + 0.055 W = 0.335 W
9. If PD_total > 1.13 W (or derated value per
Figure 3), then select the most appropriate
recourse and repeat steps 1 through 8:
a. Reduce Vin
b. Reconfigure LED array to reduce Vdrop
c. Reduce Iout by increasing Rext
d. Use external resistors or parallel device’s
configuration (see application note AND8156)
10. Calculate the junction temperaure using the
thermal information on Page 7 and refer to Figure
5 to check the output current drop due to the
calculated junction temperature. If desired,
compensate it by adjusting the value of Rext.
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5
TYPICAL APPLICATION CIRCUITS
Figure 7. Stop light automotive circuit using the NUD4001 device
to drive one high current LED (550 mA).
Vbat
13.5 Vdc
+
−
1
2
3
4
8
7
6
5
1
2
3
4
8
7
6
5
D1
1N4004
R1
2.7 W, 1/4 W
R2
32 W, 5.0 W
R4
32 W, 5.0 W
R3
2.7 W, 1/4 W
R3
6.7 W, 4.0 W
LED1
Luxeon
Emitter
550 mA
NUD4001 NUD4001
Q1 Q2
0
Figure 8. Dome light automotive circuit using the NUD4001 device
to drive one LED (220 mA).
Vbat
13.5 Vdc
+
−
1
2
3
4
8
7
6
5
1
2
3
4
8
7
6
5
D1
1N4004
R1
7.0 W, 1/4 W
R2
7.0 W, 1/4 W
R3
27 W, 2.0 W
LED1
Luxeon
Emitter
220 mA
NUD4001 NUD4001
Q1 Q2
0
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6
Figure 9. NUD4001 Device Configuration for PWM
Vbat
12 Vdc
+
−
1
2
3
4
8
7
6
5
LED1
LXHL−MW1D
NUD4001
Q1
0
Rext1
2.0 W, 1/4 W
Rext2
110 k, 1/4 W
LED2
LXHL−MW1D
LED3
LXHL−MW1D
PWM
Q2
2N2222
Figure 10. 12 Vac landscape lighting application circuit using the
NUD4001 device to drive three 350 mA LEDs.
1
2
3
4
8
7
6
5
D1
MURA105T3
R2
2.0 W, 1/4 W
LED3
Luxeon Emitter
350 mA
NUD4001
Q2
0
D2
MURA105T3
D3
MURA105T3
D4
MURA105T3
C1
220 mF
12 Vac from:
60 Hz Transformer or
Electronic Transformer
LED1
Luxeon Emitter
350 mA
LED2
Luxeon Emitter
350 mA
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7
THERMAL INFORMATION
NUD4001, NSVD4001 Power Dissipation
The power dissipation of the SO−8 is a function of the pad
size. This can vary from the minimum pad size for soldering
to a pad size given for maximum power dissipation. Power
dissipation for a surface mount device is determined by
TJ(max), the maximum rated junction temperature of the die,
RqJA, the thermal resistance from the device junction to
ambient, and the operating temperature, TA. Using the
values provided on the data sheet for the SO−8 package, PD
can be calculated as follows:
PD+TJmax *TA
RqJA
The values for the equation are found in the maximum
ratings table on the data sheet. Substituting these values into
the equation for an ambient temperature TA of 25°C, one can
calculate the power dissipation of the device which in this
case is 1.13 W.
PD+150°C*25°C
110°C+1.13 W
The 110°C/W for the SO−8 package assumes the use of a
FR−4 copper board with an area of 2 square inches with 2 oz
coverage to achieve a power dissipation of 1.13 W. There are
other alternatives to achieving higher dissipation from the
SOIC package. One of them is to increase the copper area to
reduce the thermal resistance. Figure 11 shows how the
thermal resistance changes for different copper areas.
Another alternative would be to use a ceramic substrate or
an aluminum core board such as Thermal Clad®. Using a
board material such as Thermal Clad or an aluminum core
board, the power dissipation can be even doubled using the
same footprint.
60
80
100
120
140
160
180
0123456789
10
BOARD AREA (in2)
qJA (°C/W)
Figure 11. qJA versus Board Area
0
50
100
150
200
250
0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10 100 100
0
R(q) (C°/W)
TIME (sec)
1S −36.9 sq. mm −0.057 in sq.
1S −75.8 sq. mm −0.117 in sq.
1S −150.0 sq. mm −0.233 in sq.
1S −321.5 sq. mm −0.498 in sq.
1S −681.0 sq. mm −1.056 in sq.
1S −1255.0 sq. mm −1.945 in sq.
Figure 12. Transient Thermal Response
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8
PACKAGE DIMENSIONS
SOIC−8 NB
CASE 751−07
ISSUE AK
SEATING
PLANE
1
4
58
N
J
X 45 _
K
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.
A
BS
D
H
C
0.10 (0.004)
DIM
A
MIN MAX MIN MAX
INCHES
4.80 5.00 0.189 0.197
MILLIMETERS
B3.80 4.00 0.150 0.157
C1.35 1.75 0.053 0.069
D0.33 0.51 0.013 0.020
G1.27 BSC 0.050 BSC
H0.10 0.25 0.004 0.010
J0.19 0.25 0.007 0.010
K0.40 1.27 0.016 0.050
M0 8 0 8
N0.25 0.50 0.010 0.020
S5.80 6.20 0.228 0.244
−X−
−Y−
G
M
Y
M
0.25 (0.010)
−Z−
Y
M
0.25 (0.010) ZSXS
M
____
1.52
0.060
7.0
0.275
0.6
0.024
1.270
0.050
4.0
0.155
ǒmm
inchesǓ
SCALE 6:1
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
SOLDERING FOOTPRINT* STYLE 25:
PIN 1. VIN
2. N/C
3. REXT
4. GND
5. IOUT
6. IOUT
7. IOUT
8. IOUT
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
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PUBLICATION ORDERING INFORMATION
N. American Technical Support: 800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81−3−5817−1050
NUD4001/D
Thermal Clad is a registered trademark of the Bergquist Company.
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