LTC3547B TheELECTRICAL CHARACTERISTICS ● denotes the specifi cations which apply over the full operatingtemperature range, otherwise specifi cations are at TA = 25°C. VCC = 3.6V, unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS ΔV Reference Voltage Line Regulation V LINEREG IN = 2.5V to 5.5V 0.3 0.5 %/V ΔV Output Voltage Load Regulation I LOADREG LOAD = 50mA to 300mA 0.5 % IS Input DC Supply Current Active Mode (Note 4) VFB1 = VFB2 = 0.95 × VFBREG 450 700 μA Shutdown RUN1 = RUN2 = 0V, VIN = 5.5V 0.1 1 μA fOSC Oscillator Frequency VFB = 0.6V ● 1.8 2.25 2.7 MHz ILIM Peak Switch Current Limit VIN = 2.5V, VFB < VFBREG, Duty Cycle < 35% Channel 1 (300mA) 400 550 mA Channel 2 (300mA) 400 550 mA RDS(ON) Channel 1 (Note 3) Top Switch On-Resistance VIN = 3.6V, ISW = 100mA 0.8 1.05 Ω Bottom Switch On-Resistance VIN = 3.6V, ISW = 100mA 0.75 1.05 Ω Channel 2 (Note 3) Top Switch On-Resistance VIN = 3.6V, ISW = 100mA 0.8 1.05 Ω Bottom Switch On-Resistance VIN = 3.6V, ISW = 100mA 0.75 1.05 Ω ISW(LKG) Switch Leakage Current VIN = 5V, VRUN = 0V 0.01 1 μA tSOFTSTART Soft-Start Time VFB From 10% to 90% Full-Scale 0.450 0.650 0.850 ms VRUN RUN Threshold High ● 0.4 1 1.2 V IRUN RUN Leakage Current ● 0.01 1 μA Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: Dynamic supply current is higher due to the internal gate charge may cause permanent damage to the device. Exposure to any Absolute being delivered at the switching frequency. Maximum Rating condition for extended periods may affect device Note 5: Guaranteed by long-term current density limitations. reliability and lifetime. Note 6: This IC includes overtemperature protection that is intended Note 2: The LTC3547BE is guaranteed to meet specifi ed performance to protect the device during momentary overload conditions. Junction from 0°C to 85°C. Specifi cations over the –40°C and 85°C operating temperature will exceed 125°C when overtemperature protection is active. temperature range are assured by design, characterization and correlation Continuous operation above the specifi ed maximum operating junction with statistical process controls. The LTC3547BI is guaranteed over the temperature may impair device reliability. –40°C to 125°C operating temperature range. Note 3: The DFN switch on-resistance is guaranteed by correlation to wafer level measurements. WUTYPICAL PERFOR A CE CHARACTERISTICS TA = 25°C unless otherwise specifi ed.Pulse Skip Mode OperationEffi ciency vs Input VoltageSupply Current vs Temperature 100 400 VOUT = 1.8V ILOAD = 0A SW, 90 AC-COUPLED 350 5V/DIV 80 VIN = 5.5V VOUT 70 300 50mV/DIV 60 250 VIN = 2.7V 50 IOUT = 0.1mA Y CURRENT (μA) I IL EFFICIENCY (%) OUT = 1mA 40 I 200 OUT = 10mA 50mA/DIV I SUPPL OUT = 100mA 30 I 3547b G01 OUT = 300mA 150 10μs/DIV 20 VIN = 3.6V VOUT = 1.8V 10 100 ILOAD = 1mA 2.5 3 3.5 4 4.5 5 5.5 –50 –25 0 25 50 75 100 VIN (V) TEMPERATURE (ºC) 3547b G02 3547b G03 3547bfb 3