Datasheet LTC3811 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | High Speed Dual, Multiphase Step-Down DC/DC Controller |
| Pages / Page | 48 / 4 — ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply … |
| File Format / Size | PDF / 552 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply over the full operating
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LTC3811
ELECTRICAL CHARACTERISTICS The
●
denotes the specifi cations which apply over the full operating junction temperature range, otherwise specifi cations are at TJ = 25°C. VIN = 12V, MODE/SYNC = 0V, unless otherwise specifi ed. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ISENSE Total Sense Pin Current VCM = 1.25V –1.5 μA (VSENSE+ + VSENSE–) VCM(CS) VSENSE+, VSENSE– Pin Common Mode 0 3.5 V Input Voltage Range
Voltage Position Amplifi er (QFN Package Only)
gm Voltage Position Transconductance, VSENSE1+ – VSENSE1– = VSENSE2+ 5.0 mS ΔICSOUT/ΔVSENSE (Note 8) – VSENSE2– = ±50mV, VCM = 1.25V, VCSOUT = 1.25V IOS(VP) Output Offset Current, Measured at VSENSE1+ – VSENSE1– = VSENSE2+ –40 40 μA CSOUT – VSENSE2– = 1.25V, VCSOUT = 1.25V
Multiphase Oscillator and Phase-Lock Loop (Note 9)
fNOM Nominal Frequency VPLL/LPF Pin Floating, MODE/SYNC = DC 450 500 550 kHz Voltage fLOW Lowest Frequency VPLL/LPF = 0V, MODE/SYNC = DC Voltage 200 250 300 kHz fHIGH Highest Frequency VPLL/LPF = INTVCC, MODE/SYNC = DC 650 750 850 kHz Voltage fSYNC(MIN) Minimum Synchronizable Frequency MODE/SYNC = External Clock 125 175 kHz fSYNC(MAX) Maximum Synchronizable Frequency MODE/SYNC = External Clock 900 1000 kHz IPLL/LPF Phase Detector Output Current Sinking fMODE/SYNC < fOSC –4.3 μA Sourcing fMODE/SYNC > fOSC 5.1 μA θ1 – θ2 Channel 1 to Channel 2 Phase VPHASMODE = 0V 180 deg Relationship (Note 9) VPHASMODE = 50% INTVCC 180 deg VPHASMODE = INTVCC 120 deg θ1 – θCLKOUT Channel 1 to CLKOUT Phase VPHASMODE = 0V 90 deg Relationship (Note 9) VPHASMODE = 50% INTVCC 60 deg VPHASMODE = INTVCC 240 deg VOL(CLKOUT) Low Level CLKOUT Output Voltage RCLK = 50k to Ground 0.2 V VOH(CLKOUT) High Level CLKOUT Output Voltage RCLK = 50k to Ground 4.0 5.8 V RMODE/SYNC MODE/SYNC Input Resistance 75 kΩ VIL(MODE/SYNC) Low Level MODE/SYNC Input Threshold 0.3 V VIH(MODE/SYNC) High Level MODE/SYNC Input Threshold 1.8 V
Power Good Indicators
VOL(PGOOD) PGOOD Voltage Low IPGOOD = 2mA 0.12 0.30 V IPGOOD(OFF) PGOOD Leakage Current VPGOOD = 6V 1.0 μA ΔVFB(OV) ΔVFB, PGOOD Overvoltage Threshold VFB(OV) – VFB(NOM) in Percent 7 10 13 % ΔVFB(UV) ΔVFB, PGOOD Undervoltage Threshold VFB(UV) – VFB(NOM) in Percent –13 –10 –7 % ΔVFB(HYST) ΔVFB, PGOOD Comparator Hysteresis UV or OV Comparator 12 mV tPG(FAULT) Delay from UV/OV Condition to PGOOD 145 μs Falling tPG(OK) Delay from UV/OV Fault Recovery to 38 μs PGOOD Rising
Thermal Protection
TJSD Thermal Shutdown Junction (Note 6) 165 °C Temperature TJSD(HYST) Thermal Shutdown Junction (Note 6) 25 °C Temperature Hysteresis 3811f 4
ELECTRICAL CHARACTERISTICS The
●
denotes the specifi cations which apply over the full operating junction temperature range, otherwise specifi cations are at TJ = 25°C. VIN = 12V, MODE/SYNC = 0V, unless otherwise specifi ed. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ISENSE Total Sense Pin Current VCM = 1.25V –1.5 μA (VSENSE+ + VSENSE–) VCM(CS) VSENSE+, VSENSE– Pin Common Mode 0 3.5 V Input Voltage Range
Voltage Position Amplifi er (QFN Package Only)
gm Voltage Position Transconductance, VSENSE1+ – VSENSE1– = VSENSE2+ 5.0 mS ΔICSOUT/ΔVSENSE (Note 8) – VSENSE2– = ±50mV, VCM = 1.25V, VCSOUT = 1.25V IOS(VP) Output Offset Current, Measured at VSENSE1+ – VSENSE1– = VSENSE2+ –40 40 μA CSOUT – VSENSE2– = 1.25V, VCSOUT = 1.25V
Multiphase Oscillator and Phase-Lock Loop (Note 9)
fNOM Nominal Frequency VPLL/LPF Pin Floating, MODE/SYNC = DC 450 500 550 kHz Voltage fLOW Lowest Frequency VPLL/LPF = 0V, MODE/SYNC = DC Voltage 200 250 300 kHz fHIGH Highest Frequency VPLL/LPF = INTVCC, MODE/SYNC = DC 650 750 850 kHz Voltage fSYNC(MIN) Minimum Synchronizable Frequency MODE/SYNC = External Clock 125 175 kHz fSYNC(MAX) Maximum Synchronizable Frequency MODE/SYNC = External Clock 900 1000 kHz IPLL/LPF Phase Detector Output Current Sinking fMODE/SYNC < fOSC –4.3 μA Sourcing fMODE/SYNC > fOSC 5.1 μA θ1 – θ2 Channel 1 to Channel 2 Phase VPHASMODE = 0V 180 deg Relationship (Note 9) VPHASMODE = 50% INTVCC 180 deg VPHASMODE = INTVCC 120 deg θ1 – θCLKOUT Channel 1 to CLKOUT Phase VPHASMODE = 0V 90 deg Relationship (Note 9) VPHASMODE = 50% INTVCC 60 deg VPHASMODE = INTVCC 240 deg VOL(CLKOUT) Low Level CLKOUT Output Voltage RCLK = 50k to Ground 0.2 V VOH(CLKOUT) High Level CLKOUT Output Voltage RCLK = 50k to Ground 4.0 5.8 V RMODE/SYNC MODE/SYNC Input Resistance 75 kΩ VIL(MODE/SYNC) Low Level MODE/SYNC Input Threshold 0.3 V VIH(MODE/SYNC) High Level MODE/SYNC Input Threshold 1.8 V
Power Good Indicators
VOL(PGOOD) PGOOD Voltage Low IPGOOD = 2mA 0.12 0.30 V IPGOOD(OFF) PGOOD Leakage Current VPGOOD = 6V 1.0 μA ΔVFB(OV) ΔVFB, PGOOD Overvoltage Threshold VFB(OV) – VFB(NOM) in Percent 7 10 13 % ΔVFB(UV) ΔVFB, PGOOD Undervoltage Threshold VFB(UV) – VFB(NOM) in Percent –13 –10 –7 % ΔVFB(HYST) ΔVFB, PGOOD Comparator Hysteresis UV or OV Comparator 12 mV tPG(FAULT) Delay from UV/OV Condition to PGOOD 145 μs Falling tPG(OK) Delay from UV/OV Fault Recovery to 38 μs PGOOD Rising
Thermal Protection
TJSD Thermal Shutdown Junction (Note 6) 165 °C Temperature TJSD(HYST) Thermal Shutdown Junction (Note 6) 25 °C Temperature Hysteresis 3811f 4
