Datasheet LT3795 (Analog Devices) - 3

LT3795
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, CTRL1 = CTRL2 = 2V, PWM = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
SENSE Input Bias Current Current Out of Pin 65 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, CTRL1 ≥ 1.2V, CTRL2 ≥ 1.2V l 243 250 257 mV (V(ISP-ISN)) ISP = 0V, CTRL1 ≥ 1.2V, CTRL2 ≥ 1.2V l 243 250 257 mV 9/10th LED Current Sense Threshold ISP = 48V, CTRL1 = 1V, CTRL2 = 1.2V l 220 225 230 mV (V(ISP-ISN)) ISP = 0V, CTRL1 = 1V, CTRL2 = 1.2V l 220 225 230 mV 1/2 LED Current Sense Threshold ISP = 48V, CTRL1 = 0.6V, CTRL2 = 1.2V l 119 125 130 mV (V(ISP-ISN)) ISP = 0V, CTRL1 = 0.6V, CTRL2 = 1.2V l 119 125 130 mV 1/10th LED Current Sense Threshold ISP = 48V, CTRL1 = 0.2V, CTRL2 = 1.2V l 16 25 32 mV (V(ISP-ISN)) ISP = 0V, CTRL1 = 0.2V, CTRL2 = 1.2V 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 Overcurrent Protection Threshold ISN = 48V l 360 375 390 mV (V(ISP-ISN)) ISN = 0V l 360 375 390 mV CTRL1, CTRL2 Input Bias Current Current Out of Pin, CTRL = 1V 50 200 nA ISP/ISN Current Sense Amplifier Input 0 110 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 350 µS VC Output Impedance 2000 kΩ VC Standby Input Bias Current PWM = 0V –20 20 nA FB Regulation Voltage (VFB) ISP = ISN = 48V l 1.230 1.250 1.270 V ISP = ISN = 48V 1.238 1.250 1.264 V FB Amplifier gm 600 µS FB Pin Input Bias Current Current Out of Pin, FB = VFB 40 200 nA FB Open LED Threshold OPENLED Falling, ISP = ISN = 48V VFB – 62mV VFB – 52mV VFB – 42mV V C/10 Comparator Threshold (V(ISP-ISN)) OPENLED Falling, FB = 1.25V, ISP = 48V 25 mV OPENLED Falling, FB = 1.25V, ISN = 0V 25 mV FB Overvoltage Threshold TG Rising VFB + 35mV VFB + 50mV VFB + 60mV V VC Current Mode Gain (∆VVC/∆VSENSE) 4.2 V/V FB SHORTLED Threshold SHORTLED Falling l 300 350 mV VC Pin Source Current VC = 1.2V 10 µA VC Pin Sink Current VC = 1.2V, FB = 1.4V 30 µA
Input Current Sense Amplifier
Input Current Sense Amplifier Input Voltage l 2.5 110 V Common Range (VIVINP/VIVINN) Input Current Sense Threshold VIVINP = 48V, VIN = 48V l 57 60 63 mV (VIVINP - VIVINN) Input Current Monitor V(IVINCOMP) VIVINP-VIVINN = 50mV, VIN = 48V l 0.94 1 1.06 V Input Bias Current (I(IVINN)) VIVINP-VIVINN = 50mV, VIN = 48V 100 1000 nA Input Current Sense Amplifier gm VIVINP-VIVINN = 60mV, VIN = 48V 3400 µS Input Step Response (to 50% of Output Step) ∆VSENSE = 60mV Step, VIN = 48V 1 µs IVINCOMP Pin Resistance to GND VIN = 48V 15 kΩ 3795fc For more information www.linear.com/LT3795 3 Document Outline Features Applications Typical Application Description 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