LT3952_15 Datasheet, PDF (1/32 Pages) Linear Technology – 60V LED Driver with 4A Switch Current

Features
n _{4000:1 True Color PWM™ Dimming}
n _{4A, 60V Internal DMOS Switch}
n _{Wide Input Voltage Range: 3V to 42V}
n _{0V to 60V Output Current Regulation with Monitor}
n _{PMOS Switch Driver for PWM and Output Disconnect}
n _{LED Short-Circuit Protection and SHORTLED Flag}
n _{Internal Spread Spectrum Frequency Modulation}
n _{Constant-Current and Constant-Voltage Regulation}
n _{Input Current Limit and Monitor}
n _{Adjustable Frequency: 200kHz to 3MHz,}
Synchronizable to an External Clock
n _{10:1 Analog Dimming}
n _{Programmable Open-LED Protection with}
OPENLED Flag
n _{Programmable VIN Undervoltage and}
Overvoltage Lockout
n _{Available in a 28-Lead TSSOP Package}
Applications
n _{Display Backlighting}
n _{Automotive and Avionic Lighting}
n _{Accurate Current-Limited Voltage Regulators}
LT3952
60V LED Driver with
4A Switch Current
Description
The LT^®3952 is a current mode step-up DC/DC converter
with an internal, 60V, 80mΩ DMOS power switch. The
LT3952 is specifically designed to drive high power LEDs
in multiple configurations. It combines input and output
current regulation loops with output voltage regulation to
operate as a flexible current/voltage source.
Programmable switching frequency with optional spread-
spectrum modulation provides EMI reduction, while still
allowing optimization of the external components for
efficiency or component size. The LED current is program-
mable with an external sense resistor, and can be adjusted
from zero to full scale with a voltage at the CTRL pin. The
external PWM input provides LED ON/OFF control and
4000:1 dimming ratio, and an internal PWM generator
delivers the efficiency of PWM dimming to standalone
or I/O limited applications. The LT3952 is available in the
thermally enhanced 28-lead TSSOP package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents including, 7199560,
7321203, 7746300. Patents pending
Typical Application
Short-Circuit Robust Boost LED Driver with Spread Spectrum Frequency Modulation
V_IN
7V TO 42V
4.7µF
4A INPUT LIMIT
15mΩ
10µH
V_IN IVINP IVINN
EN/UVLO
SW
GND
OVLO
FB
CTRL
PWM
V_REF
PWM
LT3952
ISP
ISMON
ISMON
INTV_CC
DIM
100k 100k
ISN
2.2µF
100V
×2
1M
21.5k
57V OPEN LED
REGULATION
750mΩ
OPENLED
SHORTLED
OPENLED
SHORTLED
V_C
3.6k
IVINCOMP RT
TG
INTV_CC
SYNC/SPRD
SS
8.2nF
1µF
90.9k
1MHz
100nF
INTV_CC
2.2µF
16 LED (50V)
333mA
3952 TA01a
For more information www.linear.com/LT3952
Efficiency vs Input Voltage
100
90
80
70
60
0
SSFM OFF
SSFM ON
10
20
30
40
50
V_IN (V)
3952 TA01b
3952f
1