LTC3425 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25 ° C. VIN = 1.2V, VOUT = 3.3V, RT = 15k, unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITS PMOS Turn-Off Current CCM < 0.4V –80 mA PMOS Reverse Current Limit CCM > 1.4V 0.6 A Max Duty Cycle ● 83 90 97 % Min Duty Cycle ● 0 % Frequency Accuracy RT = 15k ● 0.8 1 1.2 MHz SHDN Input High VOUT = 0V (Initial Start-Up) ● 1 V VOUT > 2.4V ● 0.65 V SHDN Input Low ● 0.25 V SHDN Input Current VSHDN = 5V or 0V 0.01 1 µA VSHDN = 2V –0.50 µA REFEN, CCM Input High ● 1.4 V REFEN, CCM Input Low ● 0.4 V REFEN, Input Current VREFEN = 5V 0.01 1 µA SYNCIN Input High (Note 7) ● 2.5 V SYNCIN Input Low (Note 7) ● 0.5 V SYNCIN Input Current VSYNCIN = 5V 0.3 1 µA CCM Input Current VCCM = 5V 2 4 µA SYNC Input Pulse Width Range ● 0.1 µs SYNC Out High 3 V SYNC Out Low 0.4 V REFOUT REFEN > 1.4V, No Load ● 1.190 1.220 1.251 V ISOURCE < 100µA, ISINK < 10µA ● 1.184 1.220 1.252 V Error Amp Transconductance 50 µS Error Amp Output High ILIM Resistor = 75k 2.2 V Error Amp Output Low 0.15 V PGOOD Threshold (Falling Edge) Referenced to Feedback Voltage ● –9.5 –11.4 –13.5 % PGOOD Hysteresis Referenced to Feedback Voltage ● 1.5 2.5 4 % PGOOD Low Voltage ISINK = 1mA (10mA Max) ● 0.12 0.25 V PGOOD Leakage VPGOOD = 5.5V ● 0.01 1 µA SS Current Source VSS = 1V 2.7 µA Burst Threshold Voltage Falling Edge ● 0.84 0.94 1.04 V Burst Threshold Hysteresis 120 mV Note 1: Absolute Maximum Ratings are those values beyond which the life Note 5: The LTC3425E is guaranteed to meet performance specifications of a device may be impaired. from 0°C to 70°C. Specifications over the –40°C to 85°C operating Note 2: Current is measured into the V temperature range are assured by design, characterization and correlation OUTS pin since the supply current is bootstrapped to the output. The current will reflect to the input supply by with statistical process controls. VOUT/(VIN • Efficiency). The outputs are not switching. Note 6: This IC includes overtemperature protection that is intended to Note 3: Once the output is started, the IC is not dependent on the V protect the device during momentary overload conditions. Junction IN supply. temperature will exceed 125°C when overtemperature protection is active. Note 4: Total with all four FETs in parallel. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 7: The typical logic threshold for this input is: VOUT/2 3425f 3
