LT3580 ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C. VIN = 5V, VSHDN = VIN unless otherwise noted. (Note 2)PARAMETERCONDITIONSMINTYPMAXUNITS Operating Voltage Range l 2.5 32 V Positive Feedback Voltage l 1.195 1.215 1.230 V Negative Feedback Voltage l 0 5 12 mV Positive FB Pin Bias Current VFB = Positive Feedback Voltage, Current Into Pin l 81 83.3 85 μA Negative FB Pin Bias Current VFB = Negative Feedback Voltage, Current Out of Pin (LT3580E, LT3580I, LT3580MP) l 81 83.3 85.5 μA (LT3580H) l 81 83.3 86 μA Error Amplifier Transconductance 230 μmhos Error Amplifier Voltage Gain 70 V/V Quiescent Current VSHDN = 2.5V, Not Switching 1 1.5 mA Quiescent Current in Shutdown VSHDN = 0V 0 1 μA Reference Line Regulation 2.5V ≤ VIN ≤ 32V 0.01 0.05 %/V Switching Frequency, fOSC RT = 45.3k (LT3580E, LT3580I, LT3580H) l 1.8 2 2.2 MHz RT = 45.3k (LT3580MP) l 1.8 2 2.25 MHz RT = 464k (LT3580E, LT3580I, LT3580H) l 180 200 220 kHz RT = 464k (LT3580MP) l 180 200 225 kHz Switching Frequency in Foldback Compared to Normal fOSC 1/4 Ratio Switching Frequency Set Range SYNCing or Free Running l 200 2500 kHz SYNC High Level for Synchronization l 1.3 V SYNC Low Level for Synchronization l 0.4 V SYNC Clock Pulse Duty Cycle VSYNC = 0V to 2V 35 65 % Recommended Minimum SYNC Ratio fSYNC/fOSC 3/4 Minimum Off-Time 60 ns Minimum On-Time 100 ns Switch Current Limit Minimum Duty Cycle (Note3) (LT3580E, LT3580I, LT3580H) l 2.2 2.5 2.8 A Minimum Duty Cycle (Note3) (LT3580MP) l 2.15 2.2 2.8 A Maximum Duty Cycle (Notes 3, 4) (LT3580E, LT3580I, l 1.6 1.9 2.6 A LT3580MP) Maximum Duty Cycle (Notes 3, 4) (LT3580H) l 1.55 1.9 2.6 A Switch VCESAT ISW = 1.5A 300 mV Switch Leakage Current VSW = 5V 0.01 1 μA Soft-Start Charging Current VSS = 0.5V l 4 6 8 μA SHDN Minimum Input Active Mode, SHDN Rising (LT3580E, LT3580I) l 1.27 1.32 1.38 V Voltage High Active Mode, SHDN Rising (LT3580H, LT3580MP) l 1.25 1.32 1.4 V Active Mode, SHDN Falling (LT3580E, LT3580I) l 1.24 1.29 1.33 V Active Mode, SHDN Falling (LT3580H, LT3580MP) l 1.22 1.29 1.35 V SHDN Input Voltage Low Shutdown Mode l 0.3 V SHDN Pin Bias Current VSHDN = 3V 40 60 μA VSHDN = 1.3V 9.7 11.6 13.4 μA VSHDN = 0V 0 0.1 μA Note 1: Stresses beyond those listed under Absolute Maximum Ratings 150°C operating junction temperature range. The LT3580MP is guaranteed may cause permanent damage to the device. Exposure to any Absolute over the full –55°C to 125°C operating junction temperature range. Maximum Rating condition for extended periods may affect device Operating lifetime is derated at junction temperatures greater than 125°C. reliability and lifetime. Note 3: Current limit guaranteed by design and/or correlation to static test. Note 2: The LT3580E is guaranteed to meet performance specifications Note 4: Current limit measured at equivalent switching frequency of 2.5MHz. from 0°C to 125°C junction temperature. Specifications over the –40°C Note 5: This IC includes overtemperature protection that is intended to 125°C operating junction temperature range are assured by design, to protect the device during momentary overload conditions. Junction characterization and correlation with statistical process controls. The temperature will exceed 150°C when overtemperature protection is active. LT3580I is guaranteed over the full –40°C to 125°C operating junction Continuous operation above the specified maximum operating junction temperature range. The LT3580H is guaranteed over the full –40°C to temperature may impair device reliability. 3580fg 3