Datasheet LT3797 (Analog Devices) - 4

LT3797
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, CTRL3, PWM1, PWM2, PWM3 = 2V; SENSEN1, SENSEN2, SENSEN3 = 0V, OVLO = 0V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
LED Current Sense Amplifier Input Common Mode l 0 100 V Range (ISN1, ISN2, ISN3) LED Overcurrent Protection Threshold ISP1, ISP2, ISP3, FBH1, FBH2, FBH3 = 12V 1000 mV (ISP1-ISN1, ISP2-ISN2, ISP3-ISN3) ISP1, ISP2, ISP3 Input Bias Current (Active) ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V 630 µA ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 0V –100 nA ISP1, ISP2, ISP3 Input Bias Current (Idle) PWM1, PWM2, PWM3=0V , ISP1, ISP2, ISP3, ISN1, 2 µA ISN2, ISN3 = 48V PWM1, PWM2, PWM3, ISP1, ISP2, ISP3, ISN1, ISN2, –40 nA ISN3 = 0V ISN1, ISN2, ISN3 Input Bias Current (Active) ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V 20 µA ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 0V –100 nA ISN1, ISN2, ISN3 Input Bias Current (Idle) PWM1, PWM2, PWM3=0V , ISP1, ISP2, ISP3, ISN1, 0 1 µA ISN2, ISN3 = 48V PWM1, PWM2, PWM3, ISP1, ISP2, ISP3, ISN1, ISN2, –20 nA ISN3 = 0V LED Current Sense Amplifier gm ISP1-ISN1, ISP2-ISN2, ISP3-ISN3 = 250mV 250 μS FBH1, FBH2, FBH3 Regulation Voltage “FBH(REG)” ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V l 1.225 1.250 1.280 V (|ISP1-FBH1, ISP2-FBH2, ISP3-FBH3|) FBH1, FBH2, FBH3 Pin Input Bias Current ISP1-FBH1, ISP2-FBH2, ISP3-FBH3 = 1.25V 40 100 nA ISP1-FBH1, ISP2-FBH2, ISP3-FBH3 = –1.25V 2 2.4 3 µA FBH1, FBH2, FBH3 Amplifier gm |ISP1-FBH1|, |ISP2-FBH2|, |ISP3-FBH3| = 1.25V 480 μS FBH1, FBH2, FBH3 Open-LED Threshold Rising (Note 4) FBH(REG) FBH(REG) FBH(REG) V (|ISP1-FBH1|, |ISP2-FBH2|, |ISP3-FBH3|) Voltage ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V – 0.07 – 0.05 – 0.04 Hysteresis 20 mV FBH1, FBH2, FBH3 Overvoltage Threshold Rising (Note 4) FBH(REG) FBH(REG) FBH(REG) V (|ISP1-FBH1|, |ISP2-FBH2|, |ISP3-FBH3|) Voltage ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V + 0.05 + 0.06 + 0.085 Hysteresis 25 mV VC1, VC2, VC3 Output Impedance 10 MΩ VC1, VC2, VC3 Standby Input Bias Current PWM1, PWM2, PWM3 = 0V –20 20 nA CTRL1, CTRL2, CTRL3 = 0V –20 20 nA VC1, VC2, VC3 Current Mode Gain –ΔVVC/ΔVSENSE 4 V/V VC1, VC2, VC3 Source Current ISP1, ISP2, ISP3, ISN1, ISN2, ISN3, FBH1, FBH2, 10.5 µA FBH3 = 48V, Current Out of Pin VC1, VC2, VC3 Sink Current ISP1, ISP2, ISP3, FBH1, FBH2, FBH3 = 48V, 12 µA ISN1, ISN2, ISN3 = 47.7V ISP1, ISP2, ISP3, ISN1, ISN2, ISN3 = 48V, 32 µA FBH1, FBH2, FBH3 = 46.7V
Oscillator
Switching Frequency RT = 154kΩ 95 100 107 kHz RT = 35.7kΩ l 375 400 425 kHz RT = 12.4kΩ 950 1000 1050 kHz RT Voltage 1.05 V GATE1, GATE2, GATE3 Minimum Off-Time CGATE = 3300pF 200 270 ns GATE1, GATE2, GATE3 Minimum On-Time CGATE = 3300pF 220 300 ns SYNC Input Low l 0.4 V Rev C 4 For more information www.analog.com Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Revision History Typical Application Related Parts 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