LT3519/LT3519-1/LT3519-2 ELECTRICAL CHARACTERISTICSThe l denotes the specifi cations which apply over the fulloperating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 12V, SHDN/UVLO = 12V, CTRL = 2V, PWM = 5V,unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITS Switching Frequency 400kHz (LT3519) l 320 400 440 kHz 1MHz (LT3519-1) l 0.80 1 1.10 MHz 2.2MHz (LT3519-2) l 1.9 2.2 2.4 MHz Maximum Duty Cycle 400kHz (LT3519) l 94 97 % 1MHz (LT3519-1) l 86 93 % 2.2MHz (LT3519-2) l 72 83 % Switch Current Limit l 750 980 1150 mA Switch VCESAT ISW = 500mA 300 mV Switch Leakage Current SW = 45V, PWM = 0V 2 μA CTRL for Full-Scale LED Current 1.2 V CTRL Pin Bias Current Current Out of Pin, CTRL = 0.1V 50 100 nA PWM Input High Voltage l 1.5 V PWM Input Low Voltage l 0.8 V PWM Pin Resistance to GND 70 kΩ FB Regulation Voltage (VFB) l 1.190 1.220 1.250 V FB Pin Threshold Voltage for OPENLED Falling VFB – 70mV VFB – 60mV VFB – 50mV V FB Pin Bias Current Current Out of Pin, FB = 1V 60 120 nA ISP , ISN Idle Input Bias Current PWM = 0V, ISP = ISN = 24V 1 μA ISP , ISN Active Input Bias Current ISP = ISN = 24V, Current per Pin 17 μA Schottky Forward Drop ISCHOTTKY = 500mA 0.8 V Schottky Leakage Current CATHODE = 24V, ANODE = 0V 4 μA SHDN/UVLO Threshold Voltage Falling l 1.180 1.220 1.270 V SHDN/UVLO Input Low Voltage IVIN Drops Below 1μA 0.4 V SHDN/UVLO Pin Bias Current Low SHDN/UVLO = 1.15V 1.8 2.2 2.6 μA SHDN/UVLO Pin Bias Current High SHDN/UVLO = 1.30V 10 100 nA VREF Output Voltage –100μA ≤ IVREF ≤ 0μA l 1.96 2 2.04 V VREF Output Pin Regulation 3V < VIN < 40V 0.04 %/V OPENLED Output Low (VOL) IOPENLED = 1mA 240 mV OPENLED Leakage Current FB = 0V, OPENLED = 40V 1 μA Note 1: Stresses beyond those listed under Absolute Maximum Ratings statistical process controls. The LT3519I/LT3519I-1/LT3519I-2 are may cause permanent damage to the device. Exposure to any Absolute guaranteed to meet performance specifi cations over the –40°C to 125°C Maximum Rating condition for extended periods may affect device operating junction temperature range. reliability and lifetime. Note 3. Absolute maximum voltage at VIN and OPENLED is 40V for Note 2. The LT3519E/LT3519E-1/LT3519E-2 are guaranteed to meet nonrepetitive one second transients and 30V for continuous operation. specifi ed performance from 0°C to 125°C junction temperature range. Note 4. For VIN below 6V, the SHDN/UVLO pin must not exceed VIN for Specifi cations over the –40°C to 125°C operating junction temperature proper operation. range are assured by design, characterization and correlation with 3519fa 3