Datasheet LTC3708 (Analog Devices) - 3

LTC3708
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, DRVCC = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loop
IQ Input DC Supply Current Normal 2.4 3 mA Shutdown 250 400 µA IFB1,2 Feedback Pin Input Current ITH = 1.2V (Notes 3, 4) –50 –100 nA VREF Internal Reference Voltage ITH = 1.2V, 0°C to 85°C (Notes 3, 4) 0.594 0.600 0.606 V ITH = 1.2V (Notes 3, 4) l 0.591 0.600 0.609 V VFB1,2 Feedback Voltage ITH = 1.2V (Note 3) 0.594 0.600 0.606 V ∆VFB(LINEREG)1,2 Feedback Voltage Line Regulation VCC = 4.5V to 6.5V (Note 3) 0.02 %/V ∆VFB(LOADREG)1,2 Feedback Voltage Load Regulation ITH = 0.5V to 1.9V (Note 3) –0.05 –0.2 % gm(EA)1,2 Error Amplifier Transconductance ITH = 1.2V (Note 3) l 1.2 1.45 1.7 mS tON1,2 On-Time ION = 60µA, VFCB = 0V 94 116 138 ns ION = 30µA, VFCB = 0V 186 233 280 ns tON(MIN)1,2 Minimum On-Time ION = 180µA 50 85 ns tOFF(MIN)1,2 Minimum Off-Time ION = 30µA 270 350 ns VSENSE(MAX)1,2 Maximum Current Sense Threshold VRNG = 1V, VFB = 0.565V 125 143 160 mV VRNG = 0V, VFB = 0.565V 90 100 110 mV VRNG = VCC, VFB = 0.565V 180 200 220 mV VSENSE(MIN)1,2 Minimum Current Sense Threshold VRNG = 1V, VFB = 0.635V –62 mV VRNG = 0V, VFB = 0.635V –42 mV VRNG = VCC, VFB = 0.635V –88 mV ∆VFB(OV)1,2 Overvoltage Fault Threshold 8.5 10 11.5 % ∆VFB(UV)1,2 Undervoltage Fault Threshold –380 –420 –460 mV VRUN/SS(ON) RUN Pin Start Threshold l 0.8 1.3 1.8 V VRUN/SS(LE) RUN Pin Latchoff Enable Threshold RUN/SS Pin Rising 2.6 3 3.3 V VRUN/SS(LT) RUN Pin Latchoff Threshold RUN/SS Pin Falling 2.2 2.5 2.8 V IRUN/SS(C) Soft-Start Charge Current VRUN/SS = 0V –0.5 –1.2 –2 µA IRUN/SS(D) Soft-Start Discharge Current VRUN/SS = VRUN/SS(LE), VFB1 or VFB2 = 0V 0.8 2 3 µA VCC(UVLO) Undervoltage Lockout VCC Falling 3.2 3.6 V VCC(UVLOR) Undervoltage Lockout Release VCC Rising 3.5 3.8 V TG RUP1,2 TG Driver Pull-Up On-Resistance TG High (Note 6) 2 Ω TG RDOWN1,2 TG Driver Pull-Down On-Resistance TG Low (Note 6) 2 Ω BG RUP1,2 BG Driver Pull-Up On-Resistance BG High (Note 6) 3 Ω BG RDOWN1,2 BG Driver Pull-Down On-Resistance BG Low (Note 6) 1 Ω
Tracking
ITRACK1,2 TRACK Pin Input Current ITH = 1.2V, VTRACK = 0.2V (Note 3) –100 –150 nA VFB(TRACK1,2) Feedback Voltage at Tracking VTRACK = 0V, ITH = 1.2V (Note 3) –10 0 –10 mV VTRACK = 0.2V, ITH = 1.2V (Note 3) 190 200 210 mV VTRACK = 0.4V, ITH = 1.2V (Note 3) 390 400 410 mV 3708fc For more information www.linear.com/LTC3708 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Operation Applications Information Package Description Typical Application Related Parts