LT3492 Triple Output LED Driver with 3000:1 PWM Dimming FEATURES DESCRIPTION n True Color PWM Dimming Delivers Up to 3000:1 The LT 3492 is a triple output DC/DC converter designed Dimming Ratio to operate as a constant-current source and is ideal for n Built-In Gate Driver for PMOS LED Disconnect driving LEDs. The LT3492 works in buck, boost or buck- n Three Independent Driver Channels with 600mA, boost mode. The LT3492 uses a xed frequency, current 60V Internal Switches mode architecture resulting in stable operation over a n Operates in Buck, Boost, Buck-Boost Modes wide range of supply and output voltages. A frequency n CTRL Pin Accurately Sets LED Current Sense adjust pin allows the user to program switching frequency Threshold Over a Range of 10mV to 100mV between 330kHz and 2.1MHz to optimize ef ciency and n Adjustable Frequency: 330kHz to 2.1MHz external component size. n Open LED Protection The external PWM input provides 3000:1 LED dimming n Wide Input Voltage Range: on each channel. Each of the three channels has a built-in Operation from 3V to 30V gate driver to drive an external LED-disconnect P-channel Transient Protection to 40V MOSFET, allowing high dimming range. The output current n Surface Mount Components range of each channel of the LT3492 is programmed with n 28-Lead (4mm 5mm) QFN and TSSOP Packages an external sense resistor. The CTRL pin is used to adjust the LED current either for APPLICATIONS analog dimming or overtemperature protection. n RGB Lighting L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear n Billboards and Large Displays Technology Corporation. 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, n Automotive and Avionic Lighting including 7199560, 7321203, and others pending. n Constant-Current Sources TYPICAL APPLICATION High Dimming Ratio Triple Output Buck-Mode LED Power Supply PV IN 58V 1F ISP1 ISP2 ISP3 s 3 330m 330m 330m ISN1 ISN2 ISN3 3000:1 PWM Dimming at 100Hz TG1 TG2 TG3 PWM 5V/DIV 10 LEDs 0.3A 0.3A 0.3A I LED 0.47F 0.47F 0.47F 0.2A/DIV I L 0.5A/DIV 33H 33H 33H 3492 TA01b 1s/DIV SW1 SW2 SW3 TG1-3 ISP1-3 V C1-3 ISN1-3 V REF V IN V CTRL1-3 IN 3V TO 24V PWM1-3 1F 150k 10k LT3492 SHDN FADJ 680pF 49.9k 1.3MHz OVP1-3 GND 3492 TA01a 3492fa 1LT3492 ABSOLUTE MAXIMUM RATINGS (Note 1) V (Note 4) ...............................................................40V Operating Junction Temperature Range IN SW1-SW3, ISN1-ISN3, ISP1-ISP3 ............................60V (Note 2) .................................................. 40C to 125C TG1-TG3 ...............................................ISP 10V to ISP Max Junction Temperature .................................... 125C PWM1-PWM3 ...........................................................20V Storage Temperature Range V , CTRL1-CTRL3, FADJ, V -V , OVP1-OVP3 ....2.5V TSSOP ............................................... 65C to 150C REF C1 C3 SHDN (Note 4) ...........................................................V UFD .................................................... 65C to 125C IN PIN CONFIGURATION TOP VIEW TOP VIEW 1 28 V SHDN IN 2 27 TG3 PWM3 3 26 ISN3 PWM2 28 27 26 25 24 23 4 25 ISP3 PWM1 PWM1 1 22 ISP3 5 24 SW3 V REF V 2 21 SW3 REF 6 23 SW2 CTRL3 CTRL3 3 20 SW2 7 22 ISP2 CTRL2 CTRL2 4 19 ISP2 GND GND 29 8 21 ISN2 29 CTRL1 CTRL1 5 18 ISN2 9 20 TG2 FADJ FADJ 6 17 TG2 10 19 SW1 V 7 16 SW1 V C3 C3 V 8 15 ISP1 11 18 ISP1 V C2 C2 9 10 11 12 13 14 12 17 ISN1 V C1 13 16 TG1 OVP3 14 15 OVP1 OVP2 UFD PACKAGE 28-LEAD (4mm s 5mm) PLASTIC QFN FE PACKAGE T = 125C, = 34C/W, = 2.7C/W JMAX JA JC 28-LEAD PLASTIC TSSOP EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 30C/W, = 10C/W JMAX JA JC EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3492EFE PBF LT3492EFE TRPBF LT3492FE 28-Lead Plastic TSSOP 40C to 125C LT3492IFE PBF LT3492IFE TRPBF LT3492FE 28-Lead Plastic TSSOP 40C to 125C LT3492EUFD PBF LT3492EUFD TRPBF 3492 40C to 125C 28-Lead (4mm 5mm) Plastic QFN LT3492IUFD PBF LT3492IUFD TRPBF 3492 28-Lead (4mm 5mm) Plastic QFN 40C to 125C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based nish parts. *For more information on lead free part marking, go to: