LT3748 e lectrical characteristics The l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C. VIN = 10V, unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITS Maximum SENSE Current Limit Threshold VC = 2.2V 95 100 105 mV l 90 100 110 mV Minimum SENSE Current Limit Threshold VC = 0V 15 mV Maximum to Minimum SENSE Threshold l 5.2 6.6 8.2 mV/mV Ratio SENSE Overcurrent Threshold VC = 2.2V 115 130 145 mV SENSE Input Bias Current VSENSE = 10mV (Note 3) 10 15 20 µA RREF Voltage VC = 1.1V 1.20 1.223 1.24 V l 1.195 1.245 V RREF Voltage Line Regulation 5V < VIN < 100V 0.005 0.025 %/V RREF Pin Bias Current (Note 3) l 35 500 nA TC Current into RREF RTC = 20k 27.5 µA Error Amplifier Voltage Gain 115 V/V Error Amplifier Transconductance ∆I = 10µA 155 µmhos VC Source Current VC = 1.1V, VRREF = 0.5V –45 µA VC Sink Current VC = 1.1V, VRREF = 2V 48 µA Flyback Comparator Trip Current Current into RFB Pin, RREF = 6.04k 10 µA Minimum GATE Off-Time 700 ns Minimum GATE On-Time 250 ns Maximum Discontinuous Off-Time VC = 0V 24 µs Maximum GATE Off-Time VRREF = 0.5V 55 µs Maximum GATE On-Time VSENSE = 0V 55 µs GATE Output Rise Time CL = 3300pF, 10% to 90% 16 ns GATE Output Fall Time CL = 3300pF, 10% to 90% 16 ns GATE Output Low (VOL) 0.05 V GATE Output High (VOH) VINTVCC – 0.05 V Note 1: Stresses beyond those listed under Absolute Maximum Ratings LT3748I is guaranteed over the full –40°C to 125°C operating junction may cause permanent damage to the device. Exposure to any Absolute temperature range. The LT3748H is guaranteed over the full –40°C to Maximum Rating condition for extended periods may affect device 150°C operating junction temperature range. The LT3748MP is guaranteed reliability and lifetime. over the full –55°C to 150°C operating junction temperature range. High Note 2: The LT3748E is guaranteed to meet performance specifications junction temperatures degrade operating lifetimes. Operating lifetime is from 0°C to 125°C junction temperature. Specifications over the –40°C derated at junction temperatures greater than 125°C. to 125°C operating junction temperature range are assured by design Note 3: Current flows out of the pin. characterization and correlation with statistical process controls. The 3748fb For more information www.linear.com/LT3748 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 Package Description Typical Application Related Parts