Datasheet LTC3856 (Analog Devices) - 3

LTC3856
orDer inForMaTion LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3856EFE#PBF LTC3856EFE#TRPBF LTC3856FE 38-Lead Plastic TSSOP –40°C to 125°C LTC3856IFE#PBF LTC3856IFE#TRPBF LTC3856FE 38-Lead Plastic TSSOP –40°C to 125°C LTC3856EUH#PBF LTC3856EUH#TRPBF 3856 32-Lead (5mm × 5mm) Plastic QFN –40°C to 125°C LTC3856IUH#PBF LTC3856IUH#TRPBF 3856 32-Lead (5mm × 5mm) Plastic QFN –40°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 15V, VRUN = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VIN Input Voltage 4.5 38 V VOUT Output Voltage 0.6 5.0 V VFB Regulated Feedback Voltage ITH Voltage = 1.2V, E-Grade (Note 4) l 0.5955 0.600 0.6045 V ITH Voltage = 1.2V, I-Grade (Note 4) l 0.593 0.600 0.607 V IFB Feedback Current (Note 4) –15 –50 nA VREFLNREG Reference Voltage Line Regulation VIN = 4.5V to 38V (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 % gm Transconductance Amplifier gm ITH = 1.2V, Sink/Source 5µA (Note 4) 2.0 mmho IQ Input DC Supply Current (Note 5) Normal Mode VIN = 15V 4.0 mA Shutdown VRUN = 0V 40 70 µA DFMAX Maximum Duty Factor In Dropout; fOSC = 500kHz 93 94 % UVLO Undervoltage Lockout VINTVCC Ramping Down l 3.0 3.2 3.4 V UVLO Hyst UVLO Hysteresis 0.6 V VOVL Feedback Overvoltage Lockout Measured at VFB l 0.64 0.66 0.68 V ISENSE+ SENSE+ Pins Bias Current Each Channel, VSENSE1,2 = 3.3V l ±1 ±2 µA ITEMP DCR Tempco Compensation Current VITEMP = 0.3V l 9 10 11 µA ITK/SS Soft-Start Charge Current VTK/SS = 0V l 1.0 1.25 1.5 µA VRUN RUN Pin On Threshold VRUN Rising l 1.1 1.22 1.35 V VRUNHYS RUN Pin On Hysteresis 80 mV VSENSE(MAX) Maximum Current Sense Threshold VFB = 0.5V, VSENSE1,2 = 3.3V (E-Grade) ILIM = 0V l 25 30 35 mV ILIM = Float l 45 50 55 mV ILIM = INTVCC l 68 75 82 mV VSENSE(MAX) Maximum Current Sense Threshold VFB = 0.5V, VSENSE1,2 = 3.3V (I-Grade) ILIM = 0V l 23 30 37 mV ILIM = Float l 43 50 57 mV ILIM = INTVCC l 66 75 84 mV 3856fa For more information www.linear.com/LTC3856 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Typical Application Related Parts