Datasheet LTC3708 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Fast 2-Phase, No RSENSE Buck Controller with Output Tracking |
| Pages / Page | 34 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| File Format / Size | PDF / 667 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the full operating
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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
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
