LTC3785 elecTrical characTerisTics The l denotes the specifications which apply over the full operating junctiontemperature range, otherwise specifications are at TA = 25°C. VIN = ISVOUT = VDRV = VBST1 = VBST2 = 3.6V, RT = 49.9k, RILSET = 59k. PARAMETERCONDITIONSMINTYPMAXUNITS Error Amp Source Current –500 µA Error Amp Sink Current 900 µA Error Amp AVOL 90 dB Overvoltage Threshold VSENSE Pin % Above FB LTC3785E l 6 10 14 % LTC3785I l 6 10 15 % Undervoltage Threshold VSENSE Pin % Below FB LTC3785E l –3.5 –6.5 –9.5 % LTC3785I l –3.5 –6.5 –10.5 % VSENSE Input Current VSENSE = Measured FB Voltage 1 500 nA VCC Regulator VCC Maximum Regulating Voltage VIN = 5V, IVCC = –20mA l 4.15 4.35 4.55 V VCC Regulation Voltage VIN = 3.6V, IVCC = –20mA l 3.3 3.5 3.6 V VCC Regulator Sink Current ISVOUT = VCC = 5V 800 µA Run/Soft-Start RUN/SS Threshold When IC is Enabled l 0.35 0.7 1.1 V When EA is at Maximum Boost Duty Cycle 1.9 V RUN/SS Input Current RUN/SS = 0V –1 µA RUN/SS Discharge Current During Current Limit 20 30 µA Current Limit Current Limit Sense Threshold ISVIN to ISSW1, RILSET = 121k l 20 60 100 mV ISVIN to ISSW1, RILSET = 59k l 55 105 155 mV Reverse Current Limit Sense Threshold ISSW2 to ISVOUT, CCM > 2V –50 –110 –170 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785E l –15 –35 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785I l –15 –40 mV Input Current ISVIN 80 150 µA ISVOUT 10 20 µA ISSW1, ISSW2 0.1 5 µA CCM Input Threshold (High) l 2.2 V CCM Input Threshold (Low) l 0.4 V CCM Input Current CCM = 3.6V 0.01 1 µA Burst Mode Operation Mode Threshold l 0.8 1.5 2.2 V Mode Input Current 0.01 1 µA tON Time 1.4 µs Oscillator Frequency Accuracy l 370 509 650 kHz Switching Characteristics Maximum Duty Cycle Boost (% Switch BG2 On) l 80 90 % Buck (% Switch TG1 On) 99 % TG1, TG2 Driver Impedance 2 Ω BG1, BG2 Driver Impedance 2 Ω TG1, TG2 Rise Time CLOAD = 3300pF (Note 3) 20 ns 3785fc Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts