LTC3542 ELECTRICAL CHARACTERISTICSThe ● denotes the specifi cations which apply over the full operatingtemperature range, otherwise specifi cations are at TA = 25°C. VIN = 3.6V unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS IS Input DC Supply Current (Note 5) Active Mode VFB = 0.5V 500 μA Sleep Mode VFB = 0.7V, MODE = 0V 26 35 μA Shutdown RUN = 0V 0.1 1 μA fOSC Oscillator Frequency VFB = 0.6V ● 1.8 2.25 2.7 MHz fSYNC Synchronous Frequency VFB = 0.6V 1 3 MHz ILIM Peak Switch Current VIN = 3V, VFB = 0.5V, Duty Cycle < 35% 650 1000 mA RDS(ON) P-Channel On Resistance (Note 6) ISW = 100mA 0.5 0.65 Ω N-Channel On Resistance (Note 6) ISW = –100mA 0.35 0.55 Ω ISW(LKG) Switch Leakage Current VIN = 5V, VRUN = 0V, VSW = 0V or 5V ±0.01 ±1 μA VUVLO Undervoltage Lockout Threshold VIN Rising 2.0 2.3 V VIN Falling 1.8 1.9 V VRUN RUN Threshold ● 0.3 1.5 V IRUN RUN Leakage Current ● ±0.01 ±1 μA VMODE/SYNC MODE/SYNC Threshold ● 0.3 1.2 V IMODE/SYNC MODE/SYNC Leakage Current ● ±0.01 ±1 μA Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: The converter is tested in a proprietary test mode that connects may cause permanent damage to the device. Exposure to any Absolute the output of the error amplifi er to the SW pin, which is connected to an Maximum Rating condition for extended periods may affect device external servo loop. reliability and lifetime. No pin should exceed 6V. Note 5: Dynamic supply current is higher due to the internal gate charge Note 2: The LTC3542 is guaranteed to meet performance specifi cations being delivered at the switching frequency. from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating Note 6: The DFN switch on resistance is guaranteed by correlation to wafer temperature range are assured by design, characterization and correlation level measurements. with statistical process controls. The LTC3542I is guaranteed over the full Note 7: TJ is calculated from the ambient temperature TA and power –40°C to 125°C operating temperature range. dissipation PD according to the following formula: Note 3: Failure to solder the Exposed Pad of the package to the PC board TJ = TA + (PD) • (θJA). will result in a thermal resistance much higher than 102°C/W. TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise specifi ed.Burst Mode OperationPulse Skip Mode OperationStart-Up from Shutdown SW 2V/DIV RUN SW 2V/DIV 2V/DIV VOUT V 50mV/DIV V OUT OUT 1V/DIV AC COUPLED 50mV/DIV AC COUPLED IL IL 100mA/DIV 100mA/DIV IL 100mA/DIV VIN = 3.6V 2μs/DIV 3542 G01 VIN = 3.6V 400ns/DIV 3542 G02 VIN = 3.6V 400μs/DIV 3542 G03 VOUT = 1.8V VOUT = 1.8V VOUT = 1.8V ILOAD = 25mA ILOAD = 25mA ILOAD = 0A FIGURE 3a CIRCUIT FIGURE 3a CIRCUIT FIGURE 3a CIRCUIT 3542fa 3