Datasheet LTC3827 (Analog Devices) - 3

LTC3827
ELECTRICAL CHARACTERISTICS The
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denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 12V, VRUN/SS1, 2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VFB1, 2 Regulated Feedback Voltage (Note 4) ITH1, 2 Voltage = 1.2V ● 0.792 0.800 0.808 V IVFB1, 2 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; ΔITH Voltage = 1.2V to 0.7V ● 0.1 0.5 % Measured in Servo Loop; ΔITH Voltage = 1.2V to 2V ● – 0.1 –0.5 % gm1, 2 Transconductance Amplifi er gm ITH1, 2 = 1.2V; Sink/Source 5μA (Note 4) 1.55 mmho IQ Input DC Supply Current (Note 5) Sleep Mode (Channel 1 On) RUN1 = 5V, RUN2 = 0V, VFB1 = 0.83V (No Load) 80 125 μA Sleep Mode (Channel 2 On) RUN1 = 0V, RUN2 = 5V, VFB2 = 0.83V (No Load) 80 125 μA Shutdown VRUN1, 2 = 0V 8 20 μA Sleep Mode (Both Channels) RUN1,2 = 5V, VFB1 = VFB2 = 0.83V 115 160 μA UVLO Undervoltage Lockout VIN Ramping Down ● 3.5 4 V VOVL Feedback Overvoltage Lockout Measured at VFB1, 2, Relative to Regulated VFB1, 2 8 10 12 % ISENSE Sense Pins Total Source Current (Each Channel) VSENSE1–, 2– = VSENSE1+, 2+ = 0V –660 μA DFMAX Maximum Duty Factor In Dropout 98 99.4 % ITRACK/SS1, 2 Soft-Start Charge Current VTRACK1, 2 = 0V 0.75 1.0 1.35 μA VRUN1, 2 ON RUN Pin ON Threshold VRUN1, VRUN2 Rising 0.5 0.7 0.9 V VSENSE(MAX) Maximum Current Sense Threshold VFB1, 2 = 0.7V,VSENSE1–, 2– = 3.3V 90 100 110 mV VFB1, 2 = 0.7V,VSENSE1–, 2– = 3.3V ● 80 100 115 mV TG Transition Time: (Note 6) TG1, 2 tr Rise Time CLOAD = 3300pF 50 90 ns TG1, 2 tf Fall Time CLOAD = 3300pF 50 90 ns BG Transition Time: (Note 6) BG1, 2 tr Rise Time CLOAD = 3300pF 40 90 ns BG1, 2 tf Fall Time CLOAD = 3300pF 40 80 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 70 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 70 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 180 ns
INTVCC Linear Regulator
VINTVCCVIN Internal VCC Voltage 8.5V < VIN < 30V, VEXTVCC = 0V 5.0 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 = Floating; PLLIN/MODE = DC Voltage 360 400 440 kHz fLOW Lowest Frequency VPLLLPF = 0V; PLLIN/MODE = DC Voltage 220 250 280 kHz fHIGH Highest Frequency VPLLLPF = INTVCC; PLLIN/MODE = DC Voltage 475 530 580 kHz fSYNCMIN Minimum Synchronizable Frequency PLLIN/MODE = External Clock; VPLLLPF = 0V 115 140 kHz 3827ff 3