Datasheet LTC3728L-1 (Analog Devices) - 3

LTC3728L-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 15V, VRUN/SS1, 2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VOSENSE1, 2 Regulated Feedback Voltage (Note 3); ITH1, 2 Voltage = 1.2V ● 0.788 0.800 0.812 V IVOSENSE1, 2 Feedback Current (Note 3) – 5 –50 nA VREFLNREG Reference Voltage Line Regulation VIN = 3.6V to 30V (Note 3) 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 3) Measured in Servo Loop; ΔITH Voltage = 1.2V to 0.7V ● 0.1 0.5 % Measured in Servo Loop; ΔITH Voltage = 1.2V to 2.0V ● – 0.1 –0.5 % gm1, 2 Transconductance Amplifi er gm ITH1, 2 = 1.2V; Sink/Source 5μA; (Note 3) 1.3 mmho gmGBW1, 2 Transconductance Amplifi er GBW ITH1, 2 = 1.2V; (Note 3) 3 MHz IQ Input DC Supply Current (Note 4) Normal Mode VIN = 15V; EXTVCC Tied to VOUT1; VOUT1 = 5V 450 μA Shutdown VRUN/SS1, 2 = 0V 20 35 μA VFCB Forced Continuous Threshold ● 0.76 0.800 0.84 V IFCB Forced Continuous Pin Current VFCB = 0.85V – 0.50 –0.18 –0.1 μA VBINHIBIT Burst Inhibit (Constant Frequency) Measured at FCB pin 4.3 4.8 V Threshold UVLO Undervoltage Lockout VIN Ramping Down ● 3.5 4 V VOVL Feedback Overvoltage Lockout Measured at VOSENSE1, 2 ● 0.84 0.86 0.88 V ISENSE Sense Pins Total Source Current (Each Channel); VSENSE1–, 2– = VSENSE1+, 2+ = 0V –90 –60 μA DFMAX Maximum Duty Factor In Dropout 98 99.4 % IRUN/SS1, 2 Soft-Start Charge Current VRUN/SS1, 2 = 1.9V 0.5 1.2 μA VRUN/SS1, 2 ON RUN/SS Pin ON Threshold VRUN/SS1, VRUN/SS2 Rising 1.0 1.5 2.0 V VSENSE(MAX) Maximum Current Sense Threshold VOSENSE1, 2 = 0.7V,VSENSE1–, 2– = 5V 65 75 85 mV VOSENSE1, 2 = 0.7V,VSENSE1–, 2– = 5V ● 62 75 88 mV TG Transition Time: (Note 5) TG1, 2 tr Rise Time CLOAD = 3300pF 55 100 ns TG1, 2 tf Fall Time CLOAD = 3300pF 55 100 ns BG Transition Time: (Note 5) BG1, 2 tr Rise Time CLOAD = 3300pF 45 100 ns BG1, 2 tf Fall Time CLOAD = 3300pF 45 90 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns BG/TG t2D Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns tON(MIN) Minimum On-Time Tested with a Square Wave (Note 6) 100 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 30V, VEXTVCC = 4V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0 to 20mA, VEXTVCC = 4V 0.2 2.0 % VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 100 200 mV VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive ● 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLFLTR = 1.2V 360 400 440 kHz fLOW Lowest Frequency VPLLFLTR = 0V 230 260 290 kHz fHIGH Highest Frequency VPLLFLTR ≥ 2.4V 480 550 590 kHz RPLLIN PLLIN Input Resistance 50 kΩ 3728l1fc 3