link to page 16 link to page 16 LT8640S-2/LT8643S-2 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C.PARAMETERCONDITIONSMINTYPMAXUNITS Spread Spectrum Modulation RT = 60.4k, VSYNC = 3.3V 22 % Frequency Range Spread Spectrum Modulation Frequency VSYNC = 3.3V 3 kHz TR/SS Source Current l 1.2 1.9 2.6 µA TR/SS Pull-Down Resistance Fault Condition, TR/SS = 0.1V 200 Ω Output Sink Current in Forced Continuous VFB = 1.01V, L = 6.8µH, RT = 60.4k 0.25 0.6 1.1 A Mode VIN to Disable Forced Continuous Mode VIN Rising 35 37 39 V Note 1: Stresses beyond those listed under Absolute Maximum Ratings temperature (TJ, in °C) is calculated from the ambient temperature (TA in may cause permanent damage to the device. Exposure to any Absolute °C) and power dissipation (PD, in Watts) according to the formula: Maximum Rating condition for extended periods may affect device TJ = TA + (PD • θJA) reliability and lifetime. where θJA (in °C/W) is the package thermal impedance. Note 2: The LT8640-2E/LT8643E is guaranteed to meet performance Note 3: θ values determined per JEDEC 51-7, 51-12. See the Applications specifications from 0°C to 125°C junction temperature. Specifications Information section for information on improving the thermal resistance over the –40°C to 125°C operating junction temperature range are assured and for actual temperature measurements of a demo board in typical by design, characterization, and correlation with statistical process operating conditions. controls. The LT8640-2I/LT8643I is guaranteed over the full –40°C to 125°C operating junction temperature range. The LT8640-2H/LT8643H is Note 4: This IC includes overtemperature protection that is intended to guaranteed over the full –40°C to 150°C operating junction temperature protect the device during overload conditions. Junction temperature will range. High junction temperatures degrade operating lifetimes. Operating exceed 150°C when overtemperature protection is active. Continuous lifetime is derated at junction temperatures greater than 125°C. The junction operation above the specified maximum operating junction temperature will reduce lifetime. Rev 0 4 For more information www.analog.com Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION E LECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATIONS RELATED PARTS