Datasheet LTC3834 (Analog Devices) - 3

LTC3834
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VRUN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VFB Regulated Feedback Voltage (Note 4); ITH Voltage = 1.2V l 0.792 0.800 0.808 V IVFB Feedback Current (Note 4) –5 –50 nA VREFLNREG Reference Voltage Line Regulation VIN = 4V to 30V (Note 4) 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) Measured in Servo Loop; ∆ITH Voltage = 1.2V to 0.7V l 0.1 0.5 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 2V l –0.1 –0.5 % gm Transconductance Amplifier gm ITH = 1.2V; Sink/Source 5µA (Note 4) 0.5 mmho IQ Input DC Supply Current (Note 5) Sleep Mode RUN = 5V, VFB = 0.83V (No Load) 30 50 µA Shutdown VRUN = 0V 4 10 µA UVLO Undervoltage Lockout VIN Ramping Down l 3.7 4 V VOVL Feedback Overvoltage Lockout Measured at VFB Relative to Regulated VFB 8 10 12 % I – + SENSE Sense Pins Total Source Current VSENSE = VSENSE = 0V –220 µA DFMAX Maximum Duty Factor In Dropout 98 99.4 % ITRACK/SS Soft-Start Charge Current VTRACK = 0V 0.85 1.1 1.45 µA VRUN ON RUN Pin ON Threshold VRUN Rising 0.5 0.7 0.9 V V – SENSE(MAX) Maximum Current Sense Threshold VFB = 0.7V, VSENSE = 3.3V l 85 100 115 mV TG Transition Time: (Note 6) TG tr Rise Time CLOAD = 3300pF 50 90 ns TG tf Fall Time CLOAD = 3300pF 50 90 ns BG Transition Time: (Note 6) BG tr Rise Time CLOAD = 3300pF 40 90 ns BG tf Fall Time CLOAD = 3300pF 40 80 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF 70 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF 70 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 200 ns
INTVCC Linear Regulator
VINTVCCVIN Internal VCC Voltage 8.5V < VIN < 30V, VEXTVCC = 0V 5 5.25 5.5 V VLDOVIN INTVCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 0V 0.2 1.0 % VINTVCCEXT Internal VCC Voltage VEXTVCC = 8.5V 7.2 7.5 7.8 V VLDOEXT INTVCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 8.5V 0.2 1.0 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLLPF = No Connect 360 400 440 kHz fLOW Lowest Frequency VPLLLPF = 0V 220 250 280 kHz fHIGH Highest Frequency VPLLLPF = INTVCC 475 530 580 kHz fSYNCMIN Minimum Synchronizable Frequency PLLIN/MODE = External Clock; VPLLLPF = 0V 115 140 kHz fSYNCMAX Maximum Synchronizable Frequency PLLIN/MODE = External Clock; VPLLLPF = 2V 650 800 kHz IPLLLPF Phase Detector Output Current Sinking Capability fPLLIN/MODE < fOSC –5 µA Sourcing Capability fPLLIN/MODE > fOSC 5 µA 3834fc For more information www.linear.com/LTC3834 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Operation Package Description Typical Application Related Parts