LTC3863 ELECTRICALCHARACTERISTICS The l denotes the specifications which apply over the specified operatingjunction temperature range, otherwise specifications are at TA = 25°C. (Note 4) VIN = 12V, unless otherwise noted. SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITSInput Supply VIN Input Voltage Operating Range 3.5 60 V VUVLO Undervoltage Lockout (VIN-VCAP) Ramping Up Threshold l 3.25 3.50 3.8 V (VIN-VCAP) Ramping Down Threshold l 3.00 3.25 3.50 V Hysteresis 0.25 V IQ Input DC Supply Current Pulse-Skipping Mode PLLIN/MODE = 0V, FREQ = 0V, 0.77 1.2 mA VFB = 0.83V (No Load) Burst Mode Operation PLLIN/MODE = Open, FREQ = 0V, 50 70 µA VFB = 0.83V (No Load) Shutdown Supply Current RUN = 0V 7 12 µA Output Sensing VREG Regulated Feedback Voltage VREG = (VFB – VFBN) VITH = 1.2V (Note 5) l 0.791 0.800 0.809 V ∆VREG Feedback Voltage Line Regulation VIN = 3.8V to 60V (Note 5) –0.005 0.005 %/V ∆VIN ∆VREG Feedback Voltage Load Regulation VITH = 0.6V to 1.8V (Note 5) –0.1 –0.015 0.1 % ∆VITH gm(EA) Error Amplifier Transconductance VITH = 1.2V, ∆IITH = ±5µA (Note 5) 1.8 mS IFBN Feedback Negative Input Bias Current –50 –10 50 nA Current Sensing VILIM Current Limit Threshold (VIN-VSENSE) VFB = 0.77V l 85 95 103 mV ISENSE SENSE Pin Input Current VSENSE = VIN 0.1 2 µA Start-Up and Shutdown VRUN RUN Pin Enable Threshold VRUN Rising l 1.22 1.26 1.32 V VRUNHYS RUN Pin Hysteresis 150 mV ISS Soft-Start Pin Charging Current VSS = 0V 10 µA Switching Frequency and Clock Synchronization f Programmable Switching Frequency RFREQ = 24.9kΩ 105 kHz RFREQ = 64.9kΩ 375 440 505 kHz RFREQ = 105kΩ 810 kHz fLO Low Switching Frequency FREQ = 0V 320 350 380 kHz fHI High Switching Frequency FREQ = Open 485 535 585 kHz fSYNC Synchronization Frequency l 75 750 kHz VCLK(IH) Clock Input High Level into PLLIN/MODE l 2 V VCLK(LO) Clock Input Low Level into PLLIN/MODE l 0.5 V fFOLD Foldback Frequency as Percentage of VFB = 0V, FREQ = 0V 18 % Programmable Frequency tON(MIN) Minimum On-Time 220 ns Rev. B For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
