Datasheet LTC3709 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Fast 2-Phase, No RSENSE , Synchronous DC/DC Controller with Tracking/Sequencing |
| Pages / Page | 24 / 3 — ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over … |
| File Format / Size | PDF / 329 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LTC3709
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VCC = 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 25 65 µA IFB FB Pin Input Current ITH = 1.2V (Note 3) – 35 – 60 nA VFB Feedback Voltage ITH = 1.2V (Note 3) ● 0.594 0.600 0.606 V ∆VFB(LINEREG) Feedback Voltage Line Regulation VCC = 4.5V to 6.5V (Note 3) 0.02 %/V ∆VFB(LOADREG) Feedback Voltage Load Regulation ITH = 0.5V to 2V (Note 3) – 0.12 – 0.2 % gm(EA) Error Amplifier Transconductance ITH = 1.2V (Note 3) 1.3 1.45 1.6 mS tON On-Time ION = 180µA, VFCB = 0V 90 116 140 ns ION = 90µA, VFCB = 0V 180 233 280 ns tON(MIN) Minimum On-Time ION = 540µA 45 100 ns tOFF(MIN) Minimum Off-Time ION = 90µA 250 350 ns VSENSE(MAX) Maximum Current Sense Threshold VRNG = 1V 124 144 166 mV VRNG = 0V 86 101 119 mV VRNG = VCC 177 202 234 mV VSENSE(MIN) Minimum Current Sense Threshold VRNG = 1V – 60 mV VRNG = 0V – 40 mV VRNG = VCC – 80 mV ∆VFB(OV) Overvoltage Fault Threshold 8.5 10 12.5 % ∆VFB(UV) Undervoltage Fault Threshold – 8.5 – 10 – 12.5 % VRUN/SS(ON) RUN Pin Start Threshold ● 0.8 1.4 2 V VRUN/SS(LE) RUN Pin Latchoff Enable Threshold RUN/SS Pin Rising 3 V VRUN/SS(LT) RUN Pin Latchoff Threshold RUN/SS Pin Falling 2.3 V IRUN/SS(C) Soft-Start Charge Current – 0.5 – 1.2 –3 µA IRUN/SS(D) Soft-Start Discharge Current 0.8 2 4 µA UVLO Undervoltage Lockout VCC Falling 3.9 4.2 V UVLO(HYS) Undervoltage Lockout Hysteresis Measured at VCC Pin 0.2 0.35 V TG RUP TG Driver Pull-Up On-Resistance TG High (Note 5) 2 Ω TG RDOWN TG Driver Pull-Down On-Resistance TG Low (Note 5) 1.5 Ω BG RUP BG Driver Pull-Up On-Resistance BG High (Note 5) 3 Ω BG RDOWN BG Driver Pull-Down On-Resistance BG Low (Note 5) 1.5 Ω
Tracking
ITRACK TRACK Pin Input Current ITH = 1.2V, VTRACK = 0.2V (Note 3) –100 –150 nA VFB(TRACK) Feedback Voltage at Tracking VTRACK = 0.1V, ITH = 1.2V (Note 3) 90 100 110 mV VTRACK = 0.3V, ITH = 1.2V (Note 3) 290 300 310 mV VTRACK = 0.5V, ITH = 1.2V (Note 3) 490 500 510 mV
PGOOD Output
∆VFBH PGOOD Upper Threshold VFB Rising 8.5 10 12.5 % ∆VFBL PGOOD Lower Threshold VFB Falling – 8.5 – 10 – 12.5 % PG Delay PGOOD Delay VFB Rising 100 µs ∆VFB(HYS) PGOOD Hysteresis VFB Returning 3.5 % IPGOOD PGOOD Leakage Current VPGOOD = 7V ±1 µA VPGL PGOOD Low Voltage IPGOOD = 5mA 0.2 0.4 V 3709fb 3
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VCC = 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 25 65 µA IFB FB Pin Input Current ITH = 1.2V (Note 3) – 35 – 60 nA VFB Feedback Voltage ITH = 1.2V (Note 3) ● 0.594 0.600 0.606 V ∆VFB(LINEREG) Feedback Voltage Line Regulation VCC = 4.5V to 6.5V (Note 3) 0.02 %/V ∆VFB(LOADREG) Feedback Voltage Load Regulation ITH = 0.5V to 2V (Note 3) – 0.12 – 0.2 % gm(EA) Error Amplifier Transconductance ITH = 1.2V (Note 3) 1.3 1.45 1.6 mS tON On-Time ION = 180µA, VFCB = 0V 90 116 140 ns ION = 90µA, VFCB = 0V 180 233 280 ns tON(MIN) Minimum On-Time ION = 540µA 45 100 ns tOFF(MIN) Minimum Off-Time ION = 90µA 250 350 ns VSENSE(MAX) Maximum Current Sense Threshold VRNG = 1V 124 144 166 mV VRNG = 0V 86 101 119 mV VRNG = VCC 177 202 234 mV VSENSE(MIN) Minimum Current Sense Threshold VRNG = 1V – 60 mV VRNG = 0V – 40 mV VRNG = VCC – 80 mV ∆VFB(OV) Overvoltage Fault Threshold 8.5 10 12.5 % ∆VFB(UV) Undervoltage Fault Threshold – 8.5 – 10 – 12.5 % VRUN/SS(ON) RUN Pin Start Threshold ● 0.8 1.4 2 V VRUN/SS(LE) RUN Pin Latchoff Enable Threshold RUN/SS Pin Rising 3 V VRUN/SS(LT) RUN Pin Latchoff Threshold RUN/SS Pin Falling 2.3 V IRUN/SS(C) Soft-Start Charge Current – 0.5 – 1.2 –3 µA IRUN/SS(D) Soft-Start Discharge Current 0.8 2 4 µA UVLO Undervoltage Lockout VCC Falling 3.9 4.2 V UVLO(HYS) Undervoltage Lockout Hysteresis Measured at VCC Pin 0.2 0.35 V TG RUP TG Driver Pull-Up On-Resistance TG High (Note 5) 2 Ω TG RDOWN TG Driver Pull-Down On-Resistance TG Low (Note 5) 1.5 Ω BG RUP BG Driver Pull-Up On-Resistance BG High (Note 5) 3 Ω BG RDOWN BG Driver Pull-Down On-Resistance BG Low (Note 5) 1.5 Ω
Tracking
ITRACK TRACK Pin Input Current ITH = 1.2V, VTRACK = 0.2V (Note 3) –100 –150 nA VFB(TRACK) Feedback Voltage at Tracking VTRACK = 0.1V, ITH = 1.2V (Note 3) 90 100 110 mV VTRACK = 0.3V, ITH = 1.2V (Note 3) 290 300 310 mV VTRACK = 0.5V, ITH = 1.2V (Note 3) 490 500 510 mV
PGOOD Output
∆VFBH PGOOD Upper Threshold VFB Rising 8.5 10 12.5 % ∆VFBL PGOOD Lower Threshold VFB Falling – 8.5 – 10 – 12.5 % PG Delay PGOOD Delay VFB Rising 100 µs ∆VFB(HYS) PGOOD Hysteresis VFB Returning 3.5 % IPGOOD PGOOD Leakage Current VPGOOD = 7V ±1 µA VPGL PGOOD Low Voltage IPGOOD = 5mA 0.2 0.4 V 3709fb 3
