Datasheet LTC3850, LTC3850-1 (Analog Devices) - 4

LTC3850/LTC3850-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 15V, VRUN1,2 = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VFB1,2 Regulated Feedback Voltage ITH1,2 Voltage = 1.2V; (Note 4) l 0.792 0.800 0.808 V IFB1,2 Feedback Current (Note 4) –10 –50 nA VREFLNREG Reference Voltage Line Regulation VIN = 6V to 24V (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 0.01 0.1 % Measured in Servo Loop; ∆ITH Voltage = 1.2V to 1.6V l –0.01 –0.1 % gm1,2 Transconductance Amplifier gm ITH1,2 = 1.2V; Sink/Source 5µA; (Note 4) 2.2 mmho IQ Input DC Supply Current (Note 5) Normal Mode VIN = 15V; EXTVCC Tied to VOUT1; VOUT1 = 5V 850 µA Shutdown VRUN1,2 = 0V 30 50 µA UVLO Undervoltage Lockout on INTVCC VINTVCC Ramping Down 3 V UVLOHYS UVLO Hysteresis 0.5 V DFMAX Maximum Duty Factor In Dropout 96 97.2 % VOVL Feedback Overvoltage Lockout Measured at VFB1,2 l 0.84 0.86 0.88 V ISENSE Sense Pin Bias Current (Each Channel) VSENSE1,2 = 3.3V ±1 ±2 µA ITK/SS1,2 Soft-Start Charge Current VTK/SS1,2 = 0V 0.9 1.3 1.7 µA VRUN1,2 RUN Pin ON Threshold VRUN1, VRUN2 Rising l 1.1 1.22 1.35 V VRUN1,2HYS RUN Pin ON Hysteresis 80 mV VSENSE(MAX) Maximum Current Sense Threshold VFB1,2 = 0.7V, VSENSE1,2 = 3.3V, ILIM = 0V l 20 30 40 mV (Note 8) VFB1,2 = 0.7V, VSENSE1,2 = 3.3V, ILIM = Float l 40 50 60 mV VFB1,2 = 0.7V, VSENSE1,2 = 3.3V, ILIM = INTVCC l 60 75 90 mV TG RUP TG Driver Pull-Up On-Resistance TG High 2.6 Ω TG RDOWN TG Driver Pull-down On-Resistance TG Low 1.5 Ω BG RUP BG Driver Pull-Up On-Resistance BG High 2.4 Ω BG RDOWN BG Driver Pull-down On-Resistance BG Low 1.1 Ω TG Transition Time: (Note 6) TG1,2 tr Rise Time CLOAD = 3300pF 25 ns TG1,2 tf Fall Time CLOAD = 3300pF 25 ns BG Transition Time: (Note 6) BG1,2 tr Rise Time CLOAD = 3300pF 25 ns BG1,2 tf Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time CLOAD = 3300pF Each Driver 30 ns BG/TG t2D Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time CLOAD = 3300pF Each Driver 30 ns tON(MIN) Minimum On-Time (Note 7) 90 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 7V < VIN < 24V 4.8 5 5.2 V VLDO INT INTVCC Load Regulation ICC = 0mA to 50mA 0.5 2 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive l 4.5 4.7 V VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 50 100 mV VLDOHYS EXTVCC Hysteresis 200 mV Rev. D 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts