LTC3731H e lecTrical characTerisTics The l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C. VCC = VRUN/SS = 5V unless otherwise noted. SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITSMain Control Loop VREGULATED Regulated Voltage at EAIN VITH = 1.2V (Note 3) 0.594 0.600 0.606 V l 0.590 0.600 0.614 V VSENSEMAX Maximum Current Sense Threshold VEAIN = 0.5V, VITH Open, 65 75 85 mV V – – – SENSE1 , VSENSE2 , VSENSE3 = 0.6V, 1.8V l 60 75 90 mV IMATCH Maximum Current Threshold Match Worst-Case Error at VSENSEMAX –5 5 % VLOADREG Output Voltage Load Regulation (Note 3) Measured in Servo Loop, ∆ITH Voltage = 1.2V to 0.7V l 0.1 0.7 % Measured in Servo Loop, ∆ITH Voltage = 1.2V to 2V l –0.1 –0.7 % VREFLNREG Output Voltage Line Regulation VCC = 4.5V to 7V 0.03 %/V gm Transconductance Amplifier gm ITH = 1.2V, Sink/Source 25µA (Note 3) l 3 5 7 mmho gmOL Transconductance Amplifier GBW ITH = 1.2V (gm • ZL, ZL = Series 1k – 100kΩ – 1nF) 3 MHz VFCB Forced Continuous Threshold l 0.54 0.60 0.66 V IFCB FCB Bias Current VFCB = 0.65V 0.2 0.7 µA VBINHIBIT Burst Inhibit Threshold Measured at FCB Pin VCC – 1.5 VCC – 0.7 VCC – 0.3 V UVR Undervoltage RUN/SS Reset VCC Lowered Until the RUN/SS Pin is Pulled Low 3.3 3.8 4.5 V UVADJ Undervoltage Lockout Threshold 1.13 1.18 1.23 V IUVADJ Undervoltage Bias Current At UVADJ Threshold 0.2 50 nA IQ Input DC Supply Current (Note 4) Normal Mode VCC = 5V 2.3 3.5 mA Shutdown VRUN/SS = 0V 50 100 µA IRUN/SS Soft-Start Charge Current VRUN/SS = 1.9V –0.8 –1.5 –2.5 µA VRUN/SS RUN/SS Pin ON Threshold VRUN/SS, Ramping Positive 1 1.5 1.9 V VRUN/SSARM RUN/SS Pin Arming Threshold VRUN/SS, Ramping Positive Until Short-Circuit 3.8 4.5 V Latch-Off is Armed VRUN/SSLO RUN/SS Pin Latch-Off Threshold VRUN/SS, Ramping Negative 3.2 V ISCL RUN/SS Discharge Current Soft-Short Condition VEAIN = 0.375V, VRUN/SS = 4.5V –5 –1.5 µA ISDLHO Shutdown Latch Disable Current VEAIN = 0.375V, VRUN/SS = 4.5V 1.5 5 µA ISENSE SENSE Pins Source Current SENSE1+, SENSE1–, SENSE2+, SENSE2–, SENSE3+, 13 20 µA SENSE3– All Equal 1.2V; Current at Each Pin DFMAX Maximum Duty Factor In Dropout, VSENSEMAX ≤ 30mV 95 98.5 % TG tR, tF Top Gate Rise Time CLOAD = 3300pF 30 90 ns Top Gate Fall Time CLOAD = 3300pF 40 90 ns BG tR, tF Bottom Gate Rise Time CLOAD = 3300pF 30 90 ns Bottom Gate Fall Time CLOAD = 3300pF 20 90 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay All Controllers, CLOAD = 3300pF Each Driver 50 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay All Controllers, CLOAD = 3300pF Each Driver 60 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time Tested with a Square Wave (Note 5) 110 ns 3731Hfb Document Outline Features Applications Description Typical Application 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