Datasheet LTC3854 (Analog Devices) - 3
| Hersteller | Analog Devices |
| Beschreibung | Small Footprint, Wide VIN Range Synchronous Step-Down DC/DC Controller |
| Seiten / Seite | 28 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| Dateiformat / Größe | PDF / 547 Kb |
| Dokumentensprache | Englisch |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the full operating
Modelllinie für dieses Datenblatt
- LTC3854EDDB#PBF LTC3854EDDB#TRMPBF LTC3854EDDB#TRMPBF LTC3854EDDB#TRPBF LTC3854EDDB#TRPBF LTC3854EMSE#PBF LTC3854EMSE#PBF LTC3854EMSE#TRPBF LTC3854EMSE#TRPBF LTC3854IDDB#PBF LTC3854IDDB#TRMPBF LTC3854IDDB#TRMPBF LTC3854IDDB#TRPBF LTC3854IDDB#TRPBF LTC3854IMSE#PBF LTC3854IMSE#PBF LTC3854IMSE#TRPBF LTC3854IMSE#TRPBF
Textversion des Dokuments
LTC3854
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, VRUN = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loop
VIN Operating Input Voltage Range 4.5 38 V VFB Regulated Feedback Voltage (Note 4); ITH Voltage = 1.2V l 0.792 0.8 0.808 V IFB Feedback Current (Note 4) ±5 ±50 nA VREFLNREG Reference Voltage Line Regulation VIN = 6V to 38V (Note 4) 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) Measured in Servo Loop; l 0.1 0.5 % ∆ITH Voltage = 0.7V to 1.2V Measured in Servo Loop; l –0.1 –0.5 % ∆ITH Voltage = 1.2V to 2V gm Transconductance Amplifier gm ITH = 1.2V; Sink/Source = 5µA (Note 4) 2.0 mmho gmGBW Transconductance Amplifier GBW ITH = 1.2V; (Guaranteed by Design) 3 MHz IQ Input DC Supply Current Normal Mode (Note 5) 2 3 mA Shutdown RUN = 0V 10 25 µA UVLO Undervoltage Lockout VIN Ramping Down; Measured at INTVCC l 3.0 3.5 V UVLOHYST Undervoltage Lockout Hysteresis VIN Ramping Down then Up; Measured at INTVCC 350 mV VOVL Feedback Overvoltage Lockout Measured at FB l 0.86 0.88 0.90 V ISENSE Sense Pins Source Current VSENSE– = VSENSE+ = 3.3V ±0.5 ±1 µA DFMAX Maximum Duty Factor In Dropout 97 98 % IRUN/SS Soft-Start Charge Current RUN/SS = 0V 0.6 1.25 2.0 µA VRUN/SS_SD Shutdown Threshold RUN/SS Pin Must be Taken Below this Value to 0.4 V Reset Part (or Put into Shutdown Mode) VRUN/SS_ON Soft-Start Threshold Soft-Start Mode 1.2 V VSENSE(MAX) Maximum Current Sense Threshold FB = 0.7V, VSENSE– = 3.3V, VIN = 6V 40 50 65 mV TG RUP TG Driver Pull-Up On Resistance TG High 2.5 Ω TG RDOWN TG Driver Pull-Down On Resistance TG Low 2.1 Ω BG RUP BG Driver Pull-Up On Resistance BG High 2.5 Ω BG RDOWN BG Driver Pull-down On Resistance BG Low 1.2 Ω TG Transition Time: (Note 6) TG tr Rise Time CLOAD = 3300pF 25 ns TG tf Fall Time CLOAD = 3300pF 25 ns BG Transition Time: (Note 6) BG tr Rise Time CLOAD = 3300pF 25 ns BG tf Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 30 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 30 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 75 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 38V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0 to 20mA 0.2 1.0 %
Oscillator
fSW Switching Frequency 360 400 440 kHz 3854fb 3 Document Outline Features Description Applications 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 Related Parts
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, VRUN = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loop
VIN Operating Input Voltage Range 4.5 38 V VFB Regulated Feedback Voltage (Note 4); ITH Voltage = 1.2V l 0.792 0.8 0.808 V IFB Feedback Current (Note 4) ±5 ±50 nA VREFLNREG Reference Voltage Line Regulation VIN = 6V to 38V (Note 4) 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) Measured in Servo Loop; l 0.1 0.5 % ∆ITH Voltage = 0.7V to 1.2V Measured in Servo Loop; l –0.1 –0.5 % ∆ITH Voltage = 1.2V to 2V gm Transconductance Amplifier gm ITH = 1.2V; Sink/Source = 5µA (Note 4) 2.0 mmho gmGBW Transconductance Amplifier GBW ITH = 1.2V; (Guaranteed by Design) 3 MHz IQ Input DC Supply Current Normal Mode (Note 5) 2 3 mA Shutdown RUN = 0V 10 25 µA UVLO Undervoltage Lockout VIN Ramping Down; Measured at INTVCC l 3.0 3.5 V UVLOHYST Undervoltage Lockout Hysteresis VIN Ramping Down then Up; Measured at INTVCC 350 mV VOVL Feedback Overvoltage Lockout Measured at FB l 0.86 0.88 0.90 V ISENSE Sense Pins Source Current VSENSE– = VSENSE+ = 3.3V ±0.5 ±1 µA DFMAX Maximum Duty Factor In Dropout 97 98 % IRUN/SS Soft-Start Charge Current RUN/SS = 0V 0.6 1.25 2.0 µA VRUN/SS_SD Shutdown Threshold RUN/SS Pin Must be Taken Below this Value to 0.4 V Reset Part (or Put into Shutdown Mode) VRUN/SS_ON Soft-Start Threshold Soft-Start Mode 1.2 V VSENSE(MAX) Maximum Current Sense Threshold FB = 0.7V, VSENSE– = 3.3V, VIN = 6V 40 50 65 mV TG RUP TG Driver Pull-Up On Resistance TG High 2.5 Ω TG RDOWN TG Driver Pull-Down On Resistance TG Low 2.1 Ω BG RUP BG Driver Pull-Up On Resistance BG High 2.5 Ω BG RDOWN BG Driver Pull-down On Resistance BG Low 1.2 Ω TG Transition Time: (Note 6) TG tr Rise Time CLOAD = 3300pF 25 ns TG tf Fall Time CLOAD = 3300pF 25 ns BG Transition Time: (Note 6) BG tr Rise Time CLOAD = 3300pF 25 ns BG tf Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 30 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 30 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 75 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 38V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0 to 20mA 0.2 1.0 %
Oscillator
fSW Switching Frequency 360 400 440 kHz 3854fb 3 Document Outline Features Description Applications 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 Related Parts