LT3570 ELECTRICAL CHARACTERISTICSThe l denotes the specifi cations which apply over the full operatingtemperature range, otherwise specifi cations are at TA = 25°C. VIN1,2,3 = 12V, VSHDN1,2,3 = 12V unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITSSW2 Error Amplifi er 2 Transconductance 195 μMho Error Amplifi er 2 Voltage Gain 100 V/V VC2 Pin Switching Threshold 700 mV VC2 to SW2 Current Gain 5.4 A/V SW2 Current Limit (Note 7) 1.5 2.4 3.1 A SW2 VCESAT ISW2 = 1A (Note 7) 240 mV SW2 Leakage Current SW2 = 0V, VIN2 = 40V, VSHDN2 = 0V 0.2 5 μA BOOST Pin Current ISW2 = 0.5A 15 mA ISW2 = 1.5A 30 mA LDO LDO Maximum Output Current VFB3 = 600mV 10 20 mA Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: Shutdown current is for each individual input current. may cause permanent damage to the device. Exposure to any Absolute Note 5: Current fl ows into the pin. Maximum Rating condition for extended periods may affect device Note 6: Current fl ows out of the pin. reliability and lifetime. Note 7: Switch current limit and switch VCESAT guaranteed by design Note 2: The LT3570E is guaranteed to meet performance specifi cations and/or correlation to static test. from 0°C to 125°C junction temperature. Specifi cations over the –40°C Note 8: 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 the maximum operating junction temperature LT3570I is guaranteed over the full –40°C to 125°C operating junction range when overtemperature protection is active. Continuous operation temperature range. above the specifi ed maximum operating junction temperature may impair Note 3: VIN2 supplies power for the part. VIN1 supplies power only to the device reliability. boost converter. VIN3 supplies power only to the LDO Controller. TYPICAL PERFORMANCE CHARACTERISTICSFeedback Voltage vs TemperatureFrequency vs TemperatureSoft-Start Current vs Temperature 0.800 2500 5.0 RT = 7.87k 4.8 0.795 2000 4.6 0.790 1500 4.4 0.785 RT = 20k 4.2 VOLTAGE (V) 1000 CURRENT (μA) 0.780 FREQUENCY (kHz) 4.0 RT = 44.2k 500 0.775 3.8 0.770 0 3.6 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3570 G01 3570 G02 3570 G03 3570fb 4