NSC LM3402HV, LM3402 Datasheet
June 2007
LM3402/LM3402HV
0.5A Constant Current Buck Regulator for Driving High
Power LEDs
LM3402/LM3402HV 0.5A Constant Current Buck Regulator for Driving High Power LEDs
General Description
The LM3402/02HV are monolithic switching regulators designed to deliver constant currents to high power LEDs. Ideal
for automotive, industrial, and general lighting applications,
they contain a high-side N-channel MOSFET switch with a
current limit of 735 mA (typical) for step-down (Buck) regulators. Hysteretic control with controlled on-time coupled with
an external resistor allow the converter output voltage to adjust as needed to deliver a constant current to series and
series - parallel connected arrays of LEDs of varying number
and type, LED dimming by pulse width modulation (PWM),
broken/open LED protection, low-power shutdown and thermal shutdown complete the feature set.
Typical Application
Features
Integrated 0.5A N-channel MOSFET
■
VIN Range from 6V to 42V (LM3402)
■
VIN Range from 6V to 75V (LM3402HV)
■
500 mA Output Current Over Temperature
■
Cycle-by-Cycle Current Limit
■
No Control Loop Compensation Required
■
Separate PWM Dimming and Low Power Shutdown
■
Supports all-ceramic output capacitors and capacitor-less
■
outputs
Thermal shutdown protection
■
MSOP-8, PSOP-8 Packages
■
Applications
LED Driver
■
Constant Current Source
■
Automotive Lighting
■
General Illumination
■
Industrial Lighting
■
20192101
© 2007 National Semiconductor Corporation 201921 www.national.com
Connection Diagrams
LM3402/LM3402HV
20192145
8-Lead Plastic MSOP-8 Package
NS Package Number MUA08A
20192102
8-Lead Plastic PSOP-8 Package
NS Package Number MRA08B
Ordering Information
Order Number Package Type NSC Package Drawing Supplied As
LM3402MM
LM3402MMX 3500 units on tape and reel
LM3402HVMM 1000 units on tape and reel
LM3402HVMMX 3500 units on tape and reel
LM3402MR
LM3402MRX 2500 units on tape and reel
LM3402HVMR 95 units in anti-static rails
LM3402HVMRX 2500 units on tape and reel
MSOP-8 MUA08A
PSOP-8 MRA08B
1000 units on tape and reel
95 units in anti-static rails
Pin Descriptions
Pin(s) Name Description Application Information
1 SW Switch pin Connect this pin to the output inductor and Schottky diode.
2 BOOT MOSFET drive bootstrap pin Connect a 10 nF ceramic capacitor from this pin to SW.
3 DIM Input for PWM dimming Connect a logic-level PWM signal to this pin to enable/disable the
power FET and reduce the average light output of the LED array.
4 GND Ground pin Connect this pin to system ground.
5 CS Current sense feedback pin Set the current through the LED array by connecting a resistor from
this pin to ground.
6 RON On-time control pin A resistor connected from this pin to VIN sets the regulator controlled
on-time.
7 VCC Output of the internal 7V linear
regulator
8 VIN Input voltage pin Nominal operating input range is 6V to 42V (LM3402) or 6V to 75V
DAP GND Thermal Pad Connect to ground. Place 4 to 6 vias from DAP to bottom layer ground
Bypass this pin to ground with a minimum 0.1 µF ceramic capacitor
with X5R or X7R dielectric.
(LM3402HV).
plane.
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Absolute Maximum Ratings (LM3402) (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
VIN to GND -0.3V to 45V
BOOT to GND -0.3V to 59V
SW to GND -1.5V
BOOT to VCC -0.3V to 45V
BOOT to SW -0.3V to 14V
VCC to GND -0.3V to 14V
DIM to GND -0.3V to 7V
CS to GND -0.3V to 7V
RON to GND -0.3V to 7V
Junction Temperature 150°C
Storage Temp. Range -65°C to 125°C
ESD Rating (Note 2) 2kV
Soldering Information
Lead Temperature (Soldering,
10sec) 260°C
Infrared/Convection Reflow (15sec) 235°C
Operating Ratings (LM3402) (Note 1)
V
IN
Junction Temperature Range −40°C to +125°C
Thermal Resistance θJA (MSOP-8 Package)
(Note 3) 200°C/W
Thermal Resistance θJA (PSOP-8 Package)
(Note 5) 50°C/W
6V to 42V
LM3402/LM3402HV
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Absolute Maximum Ratings (LM3402HV) (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
VIN to GND
LM3402/LM3402HV
BOOT to GND -0.3V to 90V
SW to GND -1.5V
BOOT to VCC -0.3V to 76V
BOOT to SW -0.3V to 14V
VCC to GND -0.3V to 14V
DIM to GND -0.3V to 7V
CS to GND -0.3V to 7V
RON to GND -0.3V to 7V
Junction Temperature 150°C
-0.3V to 76V
Storage Temp. Range -65°C to 125°C
ESD Rating (Note 2) 2kV
Soldering Information
Lead Temperature (Soldering,
10sec) 260°C
Infrared/Convection Reflow (15sec) 235°C
Operating Ratings (LM3402HV) (Note 1)
V
IN
Junction Temperature Range −40°C to +125°C
Thermal Resistance θJA (MSOP-8 Package)
(Note 3) 200°C/W
Thermal Resistance θJA (PSOP-8 Package)
(Note 5) 50°C/W
6V to 75V
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LM3402/LM3402HV
Electrical Characteristics V
= 24V unless otherwise indicated. Typicals and limits appearing in plain type apply
IN
for TA = TJ = +25°C. (Note 4) Limits appearing in boldface type apply over full Operating Temperature Range. Datasheet min/max
specification limits are guaranteed by design, test, or statistical analysis.
LM3402
Symbol Parameter Conditions Min Typ Max Units
SYSTEM PARAMETERS
t
ON-1
t
ON-2
On-time 1
On-time 2
VIN = 10V, RON = 200 kΩ
VIN = 40V, RON = 200 kΩ
2.1 2.75 3.4 µs
490 650 810 ns
LM3402HV
Symbol Parameter Conditions Min Typ Max Units
SYSTEM PARAMETERS
t
ON-1
t
ON-2
On-time 1
On-time 2
VIN = 10V, RON = 200 kΩ
VIN = 70V, RON = 200 kΩ
2.1 2.75 3.4 µs
290 380 470 ns
LM3402/LM3402HV
Symbol Parameter Conditions Min Typ Max Units
REGULATION AND OVER-VOLTAGE COMPARATORS
V
REF-REG
V
REF-0V
I
CS
SHUTDOWN
V
SD-TH
V
SD-HYS
OFF TIMER
t
OFF-MIN
INTERNAL REGULATOR
V
CC-REG
V
IN-DO
V
CC-BP-TH
V
CC-BP-HYS
V
CC-Z-6
V
CC-Z-8
V
CC-Z-24
V
CC-LIM
V
CC-UV-TH
V
CC-UV-HYS
V
CC-UV-DLY
I
IN-OP
I
IN-SD
CURRENT LIMIT
I
LIM
DIM COMPARATOR
V
IH
V
IL
CS Regulation Threshold CS Decreasing, SW turns on 194 200 206 mV
CS Over-voltage Threshold CS Increasing, SW turns off 300 mV
CS Bias Current CS = 0V 0.1 µA
Shutdown Threshold RON / SD Increasing 0.3 0.7 1.05 V
Shutdown Hysteresis RON / SD Decreasing 40 mV
Minimum Off-time CS = 0V 300 ns
VCC Regulated Output 6.6 7 7.4 V
VIN - VCC Dropout ICC = 5 mA, 6.0V < VIN < 8.0V 300 mV
VCC Bypass Threshold VIN Increasing 8.8 V
VCC Bypass Hysteresis VIN Decreasing 225 mV
VCC Output Impedance
(0 mA < ICC < 5 mA)
VIN = 6V 55
VIN = 8V 50
Ω
VIN = 24V 0.4
VCC Current Limit (Note 3) VIN = 24V, VCC = 0V 16 mA
VCC Under-voltage Lock-out
VCC Increasing 5.25 V
Threshold
VCC Under-voltage Lock-out
VCC Decreasing 150 mV
Hysteresis
VCC Under-voltage Lock-out
100 mV Overdrive 3 µs
Filter Delay
I
Operating Current Non-switching, CS = 0V 600 900 µA
IN
IIN Shutdown Current RON / SD = 0V 90 180 µA
Current Limit Threshold 530 735 940 mA
Logic High DIM Increasing 2.2 V
Logic Low DIM Decreasing 0.8 V
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Symbol Parameter Conditions Min Typ Max Units
I
DIM-PU
DIM Pull-up Current DIM = 1.5V 75 µA
N-MOSFET AND DRIVER
R
DS-ON
V
DR-UVLO
Buck Switch On Resistance ISW = 200mA, BOOT-SW = 6.3V 0.7 1.5
BOOT Under-voltage Lock-out
BOOT–SW Increasing 1.7 3 4 V
Threshold
LM3402/LM3402HV
V
DR-HYS
BOOT Under-voltage Lock-out
BOOT–SW Decreasing 400 mV
Hysteresis
THERMAL SHUTDOWN
T
SD
T
SD-HYS
THERMAL RESISTANCE
θ
JA
Thermal Shutdown Threshold 165 °C
Thermal Shutdown Hysteresis 25 °C
Junction to Ambient MSOP-8 Package 200 °C/W
PSOP-8 Package 50
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see Electrical Characteristics.
Note 2: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin.
Note 3: VCC provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading.
Note 4: Typical specifications represent the most likely parametric norm at 25°C operation.
Note 5: θJA of 50°C/W with DAP soldered to a minimum of 2 square inches of 1 oz. copper on the top or bottom PCB layer.
Ω
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Typical Performance Characteristics
V
vs Temperature (VIN = 24V)
REF
V
vs VIN, LM3402 (TA = 25°C)
REF
LM3402/LM3402HV
20192129
V
vs VIN, LM3402HV (TA = 25°C)
REF
20192131
Current Limit vs VIN, LM3402 (TA = 25°C)
20192130
Current Limit vs Temperature (VIN = 24V)
20192132
Current Limit vs VIN, LM3402HV (TA = 25°C)
20192133
20192134
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LM3402/LM3402HV
TON vs VIN,
RON = 100 kΩ (TA = 25°C)
TON vs VIN,
(TA = 25°C)
TON vs VIN,
(TA = 25°C)
TON vs RON, LM3402HV
(TA = 25°C)
20192135
20192137
TON vs RON, LM3402
(TA = 25°C)
VCC vs V
(TA = 25°C)
IN
20192136
20192144
20192138
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20192139
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