Datasheet LT8705A (Analog Devices) - 4

LT8705A
e lecTrical characTerisTics The
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denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, SHDN = 3V unless otherwise noted. (Note 3) PARAMETER CONDITIONS MIN TYP MAX UNITS
Gain from VC to Maximum Current Sense Voltage Boost Mode 150 mV/V (VCSP-VCSN) (A5 in the Block Diagram) Buck Mode –150 mV/V SHDN Input Voltage High SHDN Rising to Enable the Device l 1.184 1.234 1.284 V SHDN Input Voltage High Hysteresis 50 mV SHDN Input Voltage Low Device Disabled, Low Quiescent Current (LT8705AE, LT8705AI) l 0.35 V (LT8705AH, LT8705AMP) l 0.3 V SHDN Pin Bias Current VSHDN = 3V 0 1 µA VSHDN = 12V 11 22 µA SWEN Rising Threshold Voltage (Note 5) l 1.156 1.206 1.256 V SWEN Threshold Voltage Hysteresis (Note 5) 22 mV MODE Pin Forced Continuous Mode Threshold l 0.4 V MODE Pin Burst Mode Range l 1.0 1.7 V MODE Pin Discontinuous Mode Threshold l 2.3 V Soft-Start Charging Current VSS = 0.5V 13 19 25 µA Soft-Start Discharge Current VSS = 0.5V 9.5 µA
Voltage Regulator Loops (Refer to Block Diagram to Locate Amplifiers)
Regulation Voltage for FBOUT VC = 1.2V (LT8705AE, LT8705AI) l 1.193 1.207 1.222 V VC = 1.2V (LT8705AH, LT8705AMP) l 1.191 1.207 1.222 V Regulation Voltage for FBIN VC = 1.2V (LT8705AE, LT8705AI) l 1.184 1.205 1.226 V VC = 1.2V (LT8705AH, LT8705AMP) l 1.182 1.205 1.226 V Line Regulation for FBOUT and FBIN Error Amp Reference VIN = 12V to 80V; Not Switching 0.002 0.005 %/V Voltage FBOUT Pin Bias Current Current Out of Pin 15 nA FBOUT Error Amp EA4 gm 315 µmho FBOUT Error Amp EA4 Voltage Gain 220 V/V FBIN Pin Bias Current Current Out of Pin 10 nA FBIN Error Amp EA3 gm 130 µmho FBIN Error Amp EA3 Voltage Gain 90 V/V SRVO_FBIN Activation Threshold (Note 5) (VFBIN Falling) – (Regulation Voltage for FBIN), 56 72 89 mV VFBOUT = VIMON_IN = VIMON_OUT = 0V SRVO_FBIN Activation Threshold Hysteresis (Note 5) VFBOUT = VIMON_IN = VIMON_OUT = 0V 33 mV SRVO_FBOUT Activation Threshold (Note 5) (VFBOUT Rising) – (Regulation Voltage for FBOUT), –37 –29 –21 mV VFBIN = 3V, VIMON_IN = VIMON_OUT = 0V SRVO_FBOUT Activation Threshold Hysteresis (Note 5) VFBIN = 3V, VIMON_IN = 0V, VIMON_OUT = 0V 15 mV SRVO_FBIN, SRVO_FBOUT Low Voltage (Note 5) I = 100μA l 110 330 mV SRVO_FBIN, SRVO_FBOUT Leakage Current (Note 5) VSRVO_FBIN = VSRVO_FBOUT = 2.5V l 0 1 µA
Current Regulation Loops (Refer to Block Diagram to Locate Amplifiers)
Regulation Voltages for IMON_IN and IMON_OUT VC = 1.2V l 1.187 1.208 1.229 V Line Regulation for IMON_IN and IMON_OUT Error Amp VIN = 12V to 80V; Not Switching 0.002 0.005 %/V Reference Voltage CSPIN, CSNIN Bias Current BOOST Capacitor Charge Control Block Not Active ICSPIN + ICSNIN, VCSPIN = VCSNIN = 12V 31 µA 8705af 4 For more information www.linear.com/LT8705A 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 Typical Applications Package Description Typical Application Related Parts