Datasheet LT3988 (Analog Devices) - 3

LT3988
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN1/VIN2 = 12V, unless otherwise noted. (Notes 2, 5, 6) PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN1 Quiescent Current VFB1 = 0.9V, VBD = 0V 2.7 4.5 mA VIN1 Quiescent Current VFB1 = 0.9V, VBD = 5V 1.6 3 mA VIN2 Quiescent Current VFB2 = 0.9V, VBD = 5V 250 1000 µA BD Pin Current VBD = 0V –8 –30 µA BD Pin Quiescent Current VBD = 5V 1.1 2.2 mA Shutdown Current (IVIN1+IVIN2) VEN/UVLO ≤ 0.3V 0.1 1 µA FB Voltage 0.74 0.75 0.76 V l 0.735 0.75 0.765 V FB Pin Bias Current VFB = 0.75V l –5 –100 nA FB Line Voltage Regulation 5V < VIN < 60V 0.01 %/V Switching Frequency RT = 40.2k l 0.9 1 1.1 MHz Switching Frequency RT = 200k 250 kHz Switching Frequency RT = 14.7k 2.15 MHz Switching Phase, SW1 to SW2 RT = 40.2k 150 180 210 Deg DA Comparator Current Threshold l 1.1 1.32 1.58 A Switch VSAT ISW = 1A 850 mV Switch Current Limit (Note 4) Duty Cycle = 35% 1.4 1.87 2.25 A Switch Leakage Current 0.01 1 µA Minimum Boost Voltage 2 2.5 V Boost Pin Current ISW = 1A 20 50 mA Boost Diode Forward Voltage IBD = 50mA 0.7 0.9 V Boost Diode Leakage Current VR = 5V 0.1 5 µA TRACK/SS Pin Current VTRACK/SS = 1V –0.8 –1.3 –2.2 µA SYNC Input High Voltage VIH l 1.5 V SYNC Input Low Voltage VIL l 0.4 V SYNC Input Frequency 0.25 2.5 MHz SYNC Pin Input Current VSYNC = 1.5V 0.3 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
Current limit is guaranteed by design and/or correlation to static may cause permanent damage to the device. Exposure to any Absolute test. Slope compensation reduces current at higher duty cycles. Maximum Rating condition for extended periods may affect device
Note 5:
Polarity specification for all currents into pins is positive. All reliability and lifetime. voltages are referenced to GND unless otherwise specified.
Note 2:
The LT3988E is guaranteed to meet performance specifications
Note 6:
This IC includes overtemperature protection that is intended from 0°C to 125°C junction temperature. Specifications over the –40°C to protect the device during momentary overload conditions. Junction to 125°C operating junction temperature range are assured by design, temperature will exceed the maximum operating junction temperature characterization and correlation with statistical process controls. The when overtemperature protection is active. Continuous operation above LT3988I is guaranteed over the full –40°C to 125°C operating junction the specified maximum operating junction temperature may impair device temperature range. The LT3988H is guaranteed over the full –40°C to reliability. 150°C operating junction temperature range. High junction temperatures
Note 7:
Absolute Maximum Voltage at V degrade operating lifetimes. Operating lifetime is derated at junction IN and EN/UVLO is 80V for nonrepetitive 1 second transients, and 60V for continuous operation. temperatures greater than 125°C.
Note 8:
If V
Note 3:
Undervoltage lockout occurs when V IN2 is driven above 60V, VIN2 must be connected to VIN1. IN is lower than the undervoltage threshold. Overvoltage lockout occurs when VIN exceeds the threshold voltage. See Applications Information. 3988f 3 Document Outline Features Applications Description 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