LM3401 Datasheet, PDF (1/23 Pages) National Semiconductor (TI) – Hysteretic PFET Controller for High Power LED Drive

LM3401
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SNVS516B – AUGUST 2007 – REVISED OCTOBER 2011
LM3401 Hysteretic PFET Controller for High Power LED Drive
Check for Samples: LM3401
FEATURES
1
•2 Hysteretic Control for Speed and Simplicity
• Input Operating Range of 4.5V-35V
• 1.5MHz maximum switching frequency
• Low 200mV reference voltage
• Programmable current limit
• High speed CMOS compatible enable/dimming
• Adjustable hysteresis
• Input UVLO
• No output capacitor required
• MSOP-8 package
APPLICATIONS
• LED Driver
• Battery Charger
DESCRIPTION
The LM3401 is a switching controller designed to provide constant current to high power LEDs. The LM3401
drives an external P-MOSFET switch for step-down (Buck) regulators. The LM3401 delivers constant current
within ±6% accuracy to a wide variety and number of series connected LEDs. Output current is adjusted with an
external current sensing resistor to drive high power LEDs in excess of 1A.
For improved accuracy and efficiency, the LM3401 features dual-side hysteresis, very low reference voltage, and
short propagation delay. A cycle by cycle current limit provides protection against over current and short circuit
failures. Additional features include adjustable hysteresis and a CMOS compatible input pin for PWM dimming.
Typical Application Circuit
V_IN = 4.5V to 35V
C1
R2
VIN
DIM
HYS
GND
R3
ILIM
HG
LM3401
CS
SNS
Q1
L1
D1
LED
current
R1
Connection Diagram
CS
1
DIM
2
SNS
3
HYS
4
8
ILIM
7
VIN
6
HG
5
GND
Figure 1. Top View
8-Lead Plastic MSOP
1
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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