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LM3421-Q1, LM3423-Q1
SNVSB95 –JULY 2019
LM342x-Q1 N -Channel Controllers for Constant-Current LED Drivers
1 Features
3 Description
The LM3421-Q1 and LM3423-Q1 family of devices
are versatile high voltage N-channel MOSFET
controllers for LED drivers. They can be easily
configured in buck, boost, buck-boost and SEPIC
topologies. This flexibility, along with an input voltage
rating of 75 V, makes the these controllers ideal for
illuminating LEDs in a large family of applications.
1
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AEC Qualified for Automotive Applications
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Device Temperature Grade 1: −40°C ≤ TA ≤
125°C (LM3421-Q1 and LM3423-Q1)
–
Device Temperature Grade 0: −40°C ≤ TA ≤
150°C (LM3421-Q0 and LM3423-Q0)
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VIN Range From 4.5 V to 75 V
Adjustable high-side current sense voltage allows for
tight regulation of the LED current with the highest
efficiency possible. The LM3421-Q1 and LM3423-Q1
devices use predictive off-time (PRO) control, which
is a combination of peak current-mode control and a
predictive off-timer. This method of control eases the
design of loop compensation while providing inherent
input voltage feed-forward compensation.
High-Side Adjustable Current Sense
2-Ω, 1-A Peak MOSFET Gate Driver
Input Undervoltage and Output Overvoltage
Protection
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PWM and Analog Dimming
Cycle-by-Cycle Current Limit
Programmable Switching Frequency
Zero Current Shutdown and Thermal Shutdown
The LM3421-Q1 and LM3423-Q1 devices include a
high-voltage start-up regulator that operates over a
wide input range of 4.5 V to 75 V. The internal PWM
controller is designed for adjustable switching
frequencies of up to 2 MHz, thus enabling compact
solutions.
LED Output Status Flag (LM3423-Q1 and
LM3423-Q0 Only)
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Fault Status Flag and Timer(LM3423-Q1 and
LM3423-Q0 Only)
Device Information(1)
2 Applications
PART NUMBER
LM3421-Q1
PACKAGE
HTSSOP (16)
HTSSOP (20)
BODY SIZE (NOM)
5.00 mm × 4.40 mm
6.50 mm × 4.40 mm
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LED Drivers: Buck, Boost, Buck-Boost, and
SEPIC
LM3423-Q1
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Indoor and Outdoor Area SSL
Automotive
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
General Illumination
Constant-Current Regulators
Typical Boost Application
VIN
1
2
3
4
5
6
7
8
VIN
HSN 16
HSP 15
RPD 14
IS 13
EN
COMP
CSH
RCT
AGND
OVP
nDIM
ILED
VCC 12
GATE 11
PGND 10
PWM
DDRV
9
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.