LTC3421 ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the full operatingjunction temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, VOUT = 3.3V, RT = 28k, unless otherwise noted. PARAMETERCONDITIONSMINTYPMAXUNITS Quiescent Current—Shutdown SHDN = 0V, ENB = 0V 0.1 1 µA SHDN = 0V, ENB > 1.4V 0.2 2 µA Quiescent Current—Active (Note 3) 0.6 1.1 mA NMOS Switch Leakage 0.1 5 µA PMOS Switch Leakage 0.1 10 µA NMOS Switch On Resistance 0.1 Ω PMOS Switch On Resistance 0.14 Ω NMOS Current Limit ILIM Resistor = 105k l 1 1.5 A ILIM Resistor = 36.5k l 3 4.2 A Max Duty Cycle l 84 91 % Min Duty Cycle l 0 % Frequency Accuracy l 0.85 1 1.15 MHz SYNC Input High l 2.2 V SYNC Input Low l 0.8 V SYNC Input Current l 0.01 1 µA ENB Input High l 1.2 V ENB Input Low l 0.4 V ENB Input Current l 1 µA SHDN Input High VOUT = 0V (Initial Start-Up), ENB = 0V 1.00 V VOUT > 2.4V, ENB = 0V 0.65 V SHDN Input Low 0.25 V SHDN Input Current l 0.01 1 µA REF Output Voltage l 1.183 1.22 1.257 V REF Output Current Range –100 8 µA Error Amp Transconductance 45 µs LBI Threshold Falling Edge l 0.58 0.6 0.62 V LBI Input Current l 0.01 1 µA LBO Low Voltage VIN = 0V, ISINK = 1mA 12.0 50 mV VIN = 0V, ISINK = 20mA 0.25 0.5 V LBO Leakage VLBO = 5.5V 0.01 1 µA SS Current Source VSS = 1V 1.2 2.4 5 µA BURST Threshold Voltage Falling Edge 0.87 0.97 1.07 V Note 1: Absolute Maximum Ratings are those values beyond which the life Note 4: Once VOUT is greater than 2.4V, the IC is not dependent on the VIN of a device may be impaired. supply. Note 2: The LTC3421E is guaranteed to meet performance specifications Note 5: This IC includes overtemperature protection that is intended from 0°C to 70°C. Specifications over the 40°C to 85°C operating to protect the device during momentary overload conditions. Junction temperature range are assured by design, characterization and correlation temperature will exceed 85°C when overtemperature protection is active. with statistical process controls. Continuous operation above the specified maximum operating junction Note 3: Current is measured into the V temperature may impair device reliability. OUTS pin since the supply current is bootstrapped to the output. The current will reflect to the input supply by (VOUT/VIN) • Efficiency. The outputs are not switching. Rev. A 4 For more information www.analog.com Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Package/Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Low Voltage Start-Up Low Noise Fixed Frequency Operation Burst Mode Operation Output Disconnect and Inrush Limiting Applications Information Component Selection Typical Application Package Description Revision History Typical Application Related Parts
