Datasheet Linear Technology LT3474

Manufacturer	Linear Technology
Series	LT3474

Step-Down 1A LED Driver

Datasheets

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PDF, 226 Kb, Language: en, File uploaded: Oct 4, 2017, Pages: 20
Step-Down 1A LED Driver

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Packaging

	LT3474EFE#PBF	LT3474EFE#TRPBF	LT3474IFE#PBF	LT3474IFE#TRPBF
N	1	2	3	4
Package	TSSOP-16 Package Outline Drawing	TSSOP-16 Package Outline Drawing	TSSOP-16 Package Outline Drawing	TSSOP-16 Package Outline Drawing
Package Code	FE	FE	FE	FE
Package Index	05-08-1663 (BA)	05-08-1663 (BA)	05-08-1663 (BA)	05-08-1663 (BA)
Pin Count	16	16	16	16

Parametrics

Parameters / Models	LT3474EFE#PBF	LT3474EFE#TRPBF	LT3474IFE#PBF	LT3474IFE#TRPBF
Architecture	Improved Average Output Current Control	Improved Average Output Current Control	Improved Average Output Current Control	Improved Average Output Current Control
Demo Boards	DC1309A,DC842A	DC1309A,DC842A	DC1309A,DC842A	DC1309A,DC842A
Design Tools	LTspice File	LTspice File	LTspice File	LTspice File
Dimming	400:1 PWM ,10:1 Analog	400:1 PWM ,10:1 Analog	400:1 PWM ,10:1 Analog	400:1 PWM ,10:1 Analog
Export Control	no	no	no	no
Features	Integrated Boost Diode, Open LED Protection, True Color PWM Dimming, Resistor Set Frequency	Integrated Boost Diode, Open LED Protection, True Color PWM Dimming, Resistor Set Frequency	Integrated Boost Diode, Open LED Protection, True Color PWM Dimming, Resistor Set Frequency	Integrated Boost Diode, Open LED Protection, True Color PWM Dimming, Resistor Set Frequency
Frequency, kHz	500	500	500	500
Ishutdown, µA	0.01	0.01	0.01	0.01
Isupply, mA	2.6	2.6	2.6	2.6
Max Number of LEDs	4	4	4	4
Monolithic	yes	yes	yes	yes
Number of Outputs	1	1	1	1
Operating Temperature Range, °C	0 to 85	0 to 85	-40 to 85	-40 to 85
Output Current, A	1	1	1	1
Switch Current, A	2.1	2.1	2.1	2.1
Synchronous	no	no	no	no
Topology	Buck, LED Driver	Buck, LED Driver	Buck, LED Driver	Buck, LED Driver
Vin Max, V	36	36	36	36
Vin Min, V	4	4	4	4
Vout Max, V	15	15	15	15

Eco Plan

	LT3474EFE#PBF	LT3474EFE#TRPBF	LT3474IFE#PBF	LT3474IFE#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant

Other Options

LT3474-1 LT3474-1

Design Notes

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Wide Input Range 1A LED Driver Powers High Brightness LEDs with Automotive and 12VAC Supplies &mdash DN388
PDF, 114 Kb, File published: Mar 2, 2006
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Wide Input Range 1A LED Driver Powers High Brightness LEDs
with Automotive and 12VAC Supplies вЂ“ Design Note 388
John Tilly and Awo Ashiabor
Introduction
TodayвЂ™s ultrabright LEDs far exceed the performance
of incandescent bulbs in both efп¬Ѓciency and lifetime.
Taking full advantage of these features requires a correspondingly efп¬Ѓcient and reliable LED driver, such as the
LTВ® 3474. The LT3474 is a step-down 1A LED driver that
supports a variety of power sources, has a wide 4V to
36V input voltage range and is programmable to deliver
LED current from 35mA to 1A at up to 88% efп¬Ѓciency. It
requires minimal external circuitry and is available in a
space saving 16-lead TSSOP package.
Automotive LED Driver
Figure 1 shows the conп¬Ѓguration of the LT3474 operating
from a 12V automotive battery input. As shown, the circuit
can tolerate voltage swings from 4V to 36V, common
in an automotive environment. With an integrated NPN
switch, boost diode and sense resistor, the LT3474 cuts
the external component count to a minimum. The high
side sense allows a grounded cathode connection, easing
wiring constraints. Both PWM and analog dimming are
available with minor circuit modiп¬Ѓcation; see the LT3474 …
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High Voltage Buck Converters Drive High Power LEDs &mdash DN392
PDF, 98 Kb, File published: Jun 1, 2006
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High Voltage Buck Converters Drive High Power LEDs
Design Note 392
Keith Szolusha
Introduction
High power LEDs continue to replace traditional bulbs
in new automotive, industrial, backlight display and
architectural detail lighting systems. LEDs excel in a wide
range of performance and cost parameters, including
excellent spectral performance, long life, robustness,
falling manufacturing cost and relatively safe materials.
Linear Technology offers a large and growing family of
high voltage DC/DC converters tailored speciп¬Ѓcally to
drive high-powered LEDs.
The LTВ® 3474 and LT3475, for example, are high voltage,
high current, single-and dual-channel buck LED converters with wide PWM dimming ratios that can drive one
or more LEDs up to 1A and 1.5A for 80 lumens to 120
lumens per LED (or more as higher output LEDs become
available). These dedicated LED drivers have onboard
high voltage NPN power switches and internal sense
resistors to minimize board space, reduce component
count and simplify design.
With their high side sense resistors, the LT3474 and
LT3475 can drive LEDs tied to ground, an important …

Model Line

Series: LT3474 (4)

LT3474EFE#PBF LT3474EFE#TRPBF LT3474IFE#PBF LT3474IFE#TRPBF

Manufacturer's Classification

Power Management > LED Driver ICs > Step-Down (Buck) LED Drivers