Datasheet LTC3789 (Analog Devices) - 3

LTC3789
e lecTrical characTerisTics The
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denotes the specifications which apply over the specified 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
VIN Input Supply Voltage 4 38 V VOUT Output Voltage 0.8 38 V VFB Regulated Feedback Voltage ITH Voltage = 1.2V (Note 4), TA = –40°C to 85°C l 0.792 0.800 0.808 V ITH = 1.2V, TA = 125°C, TA = –40°C to 125°C l 0.788 0.800 0.812 V IFB Feedback Current (Note 4) –15 –50 nA VREFLNREG Reference Voltage Line Regulation VIN = 4V to 38V (Note 4) 0.002 0.02 %/V VLOADREG Output Voltage Load Regulation (Note 4) Measured in Servo Loop, ∆ITH Voltage = 1.4V to 2V l 0.01 0.1 % Measured in Servo Loop, ∆ITH Voltage = 2V to 2.5V l –0.01 –0.1 % gm Transconductance Amplifier gm ITH = 1.2V, Sink/Source 5µA (Note 4) 1.5 mmho IQ Input DC Supply Current Normal Mode (Note 5) 3 mA Shutdown VRUN = 0V 40 60 µA UVLO Undervoltage Lockout INTVCC Ramping Down 3.4 3.6 V UVLO Hyst Undervoltage Hysteresis 0.4 V I + – + SENSE SENSE Pins Current VSENSE = VSENSE = 0V 0.2 ±1 µA I – SENSE I + – + IOSENSE IOSENSE Pins Current VIOSENSE = VIOSENSE = 10V 10 14 µA I – IOSENSE ISS Soft-Start Charge Current VSS = 0V 2 3 4 µA VRUN(ON) RUN Pin On-Threshold VRUN Rising 1.22 V VRUN(HYS) RUN Pin On-Hysteresis 150 mV IRUN RUN Pin Source Current 1.2 µA IRUN(HYS) RUN Pin Hysteresis Current 5 µA VSENSE(MAX) Maximum Current Sense Threshold Buck Region, (IL Valley) VFB = 0.7V l 73 90 107 mV Boost Region, (IL Peak) VFB = 0.7V l 123 140 157 mV VSENSE(IAVG) Maximum Input/Output Average ILIM = 0V 48 50 52.5 mV Current Sense Threshold ILIM Floating 90 100 106 mV ILIM = INTVCC 130 145 160 mV RDSPFET(ON) Driver Pull-Up On-Resistance 2.6 Ω RDSNFET(ON) Driver Pull-Down On-Resistance 1.5 Ω TG tr Top Gate Rise Time 25 ns TG tf Top Gate Fall Time 25 ns BG tr Bottom Gate Rise Time 25 ns BG tf Bottom Gate Fall Time 25 ns TG/BG t1D Top Gate Off to Bottom Gate On CLOAD = 3300pF Each Driver (Note 6) 60 ns Delay Synchronous Switch-On Delay Time BG/TG t1D Bottom Gate Off to Top Gate On CLOAD = 3300pF Each Driver (Note 6) 60 ns Delay Top Switch-On Delay Time DFMAX,BOOST Maximum Duty Factor % Switch C On 90 % DON(MIN,BOOST) Minimum Duty Factor for Main % Switch C On 9 % Switch in Boost Operation DON(MIN,BUCK) Minimum Duty Factor for % Switch B On 9 % Synchronous Switch in Buck Operation 3789fc For more information www.linear.com/LTC3789 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration order information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts