Datasheet LTC7800 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Low IQ , 60V, High Frequency Synchronous Step-Down Controller |
| Pages / Page | 32 / 3 — ELECTRICAL CHARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 1.3 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The. denotes the specifications which apply over the specified
Model Line for this Datasheet
Text Version of Document
LTC7800
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2), VIN = 12V, VRUN = 5V, EXTVCC = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Operating Voltage Range 4 60 V VFB Regulated Feedback Voltage (Note 4); ITH Voltage = 1.2V –40°C to 85°C 0.792 0.800 0.808 V LTC7800E, LTC7800I l 0.788 0.800 0.812 V LTC7800H l 0.786 0.800 0.812 V IFB Feedback Current (Note 4) ±5 ±50 nA VREFLNREG Reference Voltage Line Regulation (Note 4); VIN = 4.5V to 60V 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) l 0.01 0.1 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 0.7V (Note 4) l –0.01 –0.1 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 2V gm Transconductance Amplifier gm (Note 4); ITH = 1.2V; Sink/Source 5µA 2 mmho IQ Input DC Supply Current (Note 5) Pulse Skip or Forced Continuous Mode VFB = 0.83V (No Load) 2 mA Sleep Mode VFB = 0.83V (No Load) 50 75 µA Shutdown RUN = 0V 14 25 µA UVLO Undervoltage Lockout INTVCC Ramping Up l 3.92 4.2 V INTVCC Ramping Down l 3.6 3.80 4.0 V VOVL Feedback Overvoltage Protection Measured at VFB Relative to Regulated VFB 7 10 13 % I + SENSE SENSE+ Pin Current ±1 µA I – – SENSE SENSE– Pins Current VSENSE < INTVCC – 0.5V ±2 µA V – SENSE > INTVCC + 0.5V 700 µA DFMAX Maximum Duty Factor In Dropout; VFREQ = 0V 97 98 % ITRACK/SS Soft-Start Charge Current VTRACK/SS = 0V 7 10 14 µA VRUN On RUN Pin On Threshold VRUN Rising l 1.15 1.21 1.27 V VRUN Hyst RUN Pin Hysteresis 50 mV V – SENSE(MAX) Maximum Current Sense Threshold VFB = 0.7V, VSENSE = 3.3V, ILIM = 0V l 22 30 36 mV V – FB = 0.7V, VSENSE = 3.3V, ILIM = INTVCC l 43 50 57 mV V – FB = 0.7V, VSENSE = 3.3V, ILIM = FLOAT l 64 75 85 mV
Gate Driver
TG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.5 Ω BG Pull-Up On-Resistance 2.4 Ω Pull-Down On-Resistance 1.1 Ω TG tr TG Transition Time: (Note 6) TG tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 16 ns BG tr BG Transition Time: (Note 6) BG tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 13 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF 20 ns Synchronous Switch-On Delay Time BG/TG t1D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF 20 ns Top Switch-On Delay Time 7800f For more information www.linear.com/LTC7800 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Related Parts
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2), VIN = 12V, VRUN = 5V, EXTVCC = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Operating Voltage Range 4 60 V VFB Regulated Feedback Voltage (Note 4); ITH Voltage = 1.2V –40°C to 85°C 0.792 0.800 0.808 V LTC7800E, LTC7800I l 0.788 0.800 0.812 V LTC7800H l 0.786 0.800 0.812 V IFB Feedback Current (Note 4) ±5 ±50 nA VREFLNREG Reference Voltage Line Regulation (Note 4); VIN = 4.5V to 60V 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) l 0.01 0.1 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 0.7V (Note 4) l –0.01 –0.1 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 2V gm Transconductance Amplifier gm (Note 4); ITH = 1.2V; Sink/Source 5µA 2 mmho IQ Input DC Supply Current (Note 5) Pulse Skip or Forced Continuous Mode VFB = 0.83V (No Load) 2 mA Sleep Mode VFB = 0.83V (No Load) 50 75 µA Shutdown RUN = 0V 14 25 µA UVLO Undervoltage Lockout INTVCC Ramping Up l 3.92 4.2 V INTVCC Ramping Down l 3.6 3.80 4.0 V VOVL Feedback Overvoltage Protection Measured at VFB Relative to Regulated VFB 7 10 13 % I + SENSE SENSE+ Pin Current ±1 µA I – – SENSE SENSE– Pins Current VSENSE < INTVCC – 0.5V ±2 µA V – SENSE > INTVCC + 0.5V 700 µA DFMAX Maximum Duty Factor In Dropout; VFREQ = 0V 97 98 % ITRACK/SS Soft-Start Charge Current VTRACK/SS = 0V 7 10 14 µA VRUN On RUN Pin On Threshold VRUN Rising l 1.15 1.21 1.27 V VRUN Hyst RUN Pin Hysteresis 50 mV V – SENSE(MAX) Maximum Current Sense Threshold VFB = 0.7V, VSENSE = 3.3V, ILIM = 0V l 22 30 36 mV V – FB = 0.7V, VSENSE = 3.3V, ILIM = INTVCC l 43 50 57 mV V – FB = 0.7V, VSENSE = 3.3V, ILIM = FLOAT l 64 75 85 mV
Gate Driver
TG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.5 Ω BG Pull-Up On-Resistance 2.4 Ω Pull-Down On-Resistance 1.1 Ω TG tr TG Transition Time: (Note 6) TG tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 16 ns BG tr BG Transition Time: (Note 6) BG tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 13 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF 20 ns Synchronous Switch-On Delay Time BG/TG t1D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF 20 ns Top Switch-On Delay Time 7800f For more information www.linear.com/LTC7800 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Related Parts
