Datasheet LT3796, LT3796-1 (Analog Devices) - 3

LT3796/LT3796-1
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 24V, EN/UVLO = 24V, CTRL = 2V, PWM = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Minimum Operating Voltage VIN Tied to INTVCC 6 V VIN Shutdown IQ EN/UVLO = 0V, PWM = 0V 1 µA EN/UVLO = 1.15V, PWM = 0V 12 µA VIN Operating IQ (Not Switching) RT = 82.5k to GND, FB1 = 1.5V 2.5 3 mA VREF Voltage –100µA ≤ IREF ≤ 10µA l 1.97 2.015 2.06 V VREF Pin Line Regulation 6V < VIN < 100V 1.5 m%/V VREF Pin Load Regulation –100µA < IREF < 0µA 10 m%/µA SENSE Current Limit Threshold l 100 113 125 mV SENSE Input Bias Current Current Out of Pin 60 µA SS Sourcing Current SS = 0V 28 µA SS Sinking Current ISP – ISN = 1V, SS = 2V 2.8 µA
Error Amplifier
Full Scale LED Current Sense Threshold ISP = 48V, CTRL ≥ 1.2V l 243 250 257 mV (V(ISP-ISN)) ISP = 0V, CTRL ≥ 1.2V l 243 250 257 mV 9/10th LED Current Sense Threshold CTRL = 1V, ISP = 48V l 220 225 230 mV (V(ISP-ISN)) CTRL = 1V, ISP = 0V l 220 225 230 mV 1/2 LED Current Sense Threshold CTRL = 0.6V, ISP = 48V l 119 125 131 mV (V(ISP-ISN)) CTRL = 0.6V, ISP = 0V l 119 125 131 mV 1/10th LED Current Sense Threshold CTRL = 0.2V, ISP = 48V l 16 25 32 mV (V(ISP-ISN)) CTRL = 0.2V, ISP = 0V l 16 25 32 mV ISP/ISN Current Monitor Voltage (VISMON) V(ISP-ISN) = 250mV, ISP = 48V, –50µA < IISMON < 0 µA l 0.96 1 1.04 V V(ISP-ISN) = 250mV, ISP = 0V, –50µA < IISMON < 0 µA l 0.96 1 1.04 V ISP/ISN Over Current Protection Threshold ISN = 48V l 360 375 390 mV (V(ISP-ISN)) ISN = 0V l 360 375 390 mV CTRL Input Bias Current Current Out of Pin, CTRL = 1.2V 50 200 nA ISP/ISN Current Sense Amplifier Input 0 100 V Common Mode Range ISP/ISN Input Current Bias Current PWM = 5V (Active), ISP = 48V 700 µA (Combined) PWM = 0V (Standby), ISP = 48V 0 0.1 µA ISP/ISN Current Sense Amplifier gm V(ISP-ISN) = 250mV 400 µs VC Output Impedance 2000 kΩ VC Standby Input Bias Current PWM = 0V –20 20 nA FB1, FB2 Regulation Voltage (VFB) ISP = ISN = 48V l 1.230 1.250 1.270 V ISP = ISN = 48V 1.238 1.250 1.264 V FB1 Amplifier gm 450 600 750 µS FB2 Amplifier gm 130 170 210 µS FB1, FB2 Pin Input Bias Current FB = VFB 100 200 nA FB1 Open LED Threshold VMODE Falling, ISP = ISN = 48V VFB – 70mV VFB – 60mV VFB – 50mV V C/10 Comparator Threshold (V(ISP-ISN)) VMODE Falling, FB1 = 1.25V, ISP = 48V 25 mV VMODE Falling, FB1 = 1.25V, ISN = 0V 25 mV FB1 Overvoltage Threshold FAULT Falling VFB + 35mV VFB + 50mV VFB + 60mV V FB2 Overvoltage Threshold TG Rising VFB + 35mV VFB + 50mV VFB + 60mV V VC Current Mode Gain (∆VVC/∆VSENSE) 4.2 V/V 3796fb For more information www.linear.com/3796 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts