Datasheet LT8331 (Analog Devices) - 3

link to page 2 LT8331
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, EN/UVLO = 12V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
BIAS Threshold Rising, BIAS Can Supply INTVCC l 4.10 4.4 4.65 V Falling, BIAS Cannot Supply INTVCC l 3.725 4 4.275 V VIN Falling Threshold to Supply INTVCC BIAS = 12V BIAS – 1.6V V BIAS Falling Threshold to Supply INTVCC VIN = 12V VIN – 0.4V V
FBX Regulation
FBX Regulation Voltage FBX > 0V l 1.568 1.6 1.632 V FBX < 0V l –0.820 –0.80 –0.780 V FBX Line Regulation FBX > 0V, 4.5V < VIN < 100V 0.005 0.015 %/V FBX < 0V, 4.5V < VIN < 100V 0.005 0.015 %/V FBX Pin Current FBX = 1.6V, –0.8V l –10 10 nA
Oscillator
Switching Frequency (fOSC) RT = 301k l 92 100 107 kHz RT = 100k l 279 300 321 kHz RT = 56.2k l 465 500 535 kHz Minimum On-Time SYNC = 0V 165 290 ns SYNC = INTVCC 160 290 ns Minimum Off-Time 146 230 ns SYNC/Mode, Mode Thresholds Rising to Select Pulse Skipping Mode l 2.4 V Falling to Select Burst Mode Operation l 0.6 V SYNC/Mode, Clock Thresholds Rising 2.0 2.4 V Falling 0.6 1.1 V fSYNC/fOSC Allowed Ratio RT = 100k 0.95 1 1.25 kHz SYNC Pin Current SYNC = 2V –40 40 nA
Switch
Maximum Switch Current Limit Threshold l 0.5 0.6 0.7 A Switch Overcurrent Threshold Discharges SS Pin 1.15 A Switch RDS(ON) ISW = 0.25A 1.7 Ω Switch Leakage Current VSW = 140V 0.1 1 µA
EN/UVLO Logic
EN/UVLO Pin Threshold (Rising) Start Switching l 1.576 1.74 1.90 V EN/UVLO Pin Threshold (Falling) Stop Switching l 1.556 1.6 1.644 V EN/UVLO Pin Current VEN/UVLO = 1.6V l –40 40 nA
Soft-Start
Soft-Start Charge Current SS = 1V 2 µA Soft-Start Pull-Down Resistance Fault Condition, SS = 0.1V 250 Ω
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings characterization and correlation with statistical process controls. The may cause permanent damage to the device. Exposure to any Absolute LT8331I is guaranteed over the full –40°C to 125°C operating junction Maximum Rating condition for extended periods may affect device temperature range. High junction temperatures degrade operating reliability and lifetime. lifetimes. Operating lifetime is derated at junction temperatures greater
Note 2:
INTV than 125°C. CC cannot be externally driven. No external loading is allowed on this pin.
Note 4:
The IC includes overtemperature protection that is intended to
Note 3:
The LT8331E is guaranteed to meet performance specifications protect the device during overload conditions. Junction temperature will from 0°C to 125°C junction temperature. Specifications over the –40°C exceed 150°C when overtemperature protection is active. Continuous to 125°C operating junction temperature range are assured by design, operation above the specified maximum operating junction temperature will reduce lifetime. Rev. B For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts