LTC7800 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specifiedoperating junction temperature range, otherwise specifications are at TA = 25°C (Note 2), VIN = 12V, VRUN = 5V, EXTVCC = 0V unlessotherwise noted. SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS 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