LT3689/LT3689-5 ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the full operatingjunction temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VOUT = 5V, unless otherwise noted. (Note 3)SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS tUV UV Detect to RST Asserted Step VFB from 0.9V to 0.5V l 10 30 65 µs WDI Input Threshold l 0.4 0.95 1.15 V WDI Input Pull-Up Current –2 µA WDI Input Pulse Width l 300 ns W/T Threshold Voltage l 0.4 0.8 1 V W/T Input Pull-Down Current 2.6 µA WDE Threshold Voltage l 0.4 0.8 1 V WDO Pull-Up Current (Note 6) –0.6 –0.85 µA RST Pull-Up Current (Note 6) –0.6 –0.85 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 limit at higher duty cycles. Maximum Rating condition for extended periods may affect device Note 5: This IC includes overtemperature protection that is intended reliability and lifetime. to protect the device during momentary overload conditions. Junction Note 2: Absolute maximum voltage at VIN and EN/UVLO pins is 60V for temperature will exceed 150°C when overtemperature protection is active. nonrepetitive 1 second transients, and 36V for continuous operation. Continuous operation above the specified maximum operating junction Note 3: The LT3689E is guaranteed to meet performance specifications temperature may impair device reliability. from 0°C to 125°C junction temperature. Specifications over the –40°C Note 6: The output of RST and WDO has a weak pull-up to VOUT of to 125°C operating junction temperature range are assured by design, typically 1µA. However, external pull-up resistors may be used when faster characterization and correlation with statistical process controls. The rise times are required or for VOH higher than VOUT. LT3689I is guaranteed over the full –40°C to 125°C operating junction Note 7: Polarity specification for all currents into pins is positive. All temperature range. The LT3689H is guaranteed over the full –40°C to voltages are referenced to GND unless otherwise specified. 150°C operating junction temperature range. High junction temperatures Note 8: For the LT3689-5, V degrade operating lifetimes. Operating lifetime is derated at junction OUT is set to 5.5V to ensure the switching. temperatures greater than 125°C. TYPICAL PERFORMANCE CHARACTERISTICSEfficiency, VOUT = 5VEfficiency, VOUT = 3.3VEfficiency, VOUT = 1.8V 95 90 80 TA = 25°C TA = 25°C TA = 25°C f = 1MHz f = 700kHz f = 1MHz VIN = 5V V 90 IN = 12V 75 85 VIN = 12V V 85 V IN = 12V IN = 24V VIN = 24V 70 80 80 65 75 VIN = 32V EFFICIENCY (%) 75 EFFICIENCY (%) EFFICIENCY (%) 60 VIN = 32V 70 70 55 65 65 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 3689 G01 3689 G02 3689 G03 3689fe 4 For more information www.linear.com/LT3689 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagrams Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts