LT8645S/LT8646S ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C.PARAMETERCONDITIONSMINTYPMAXUNITS PG Hysteresis 0.4 % PG Leakage VPG = 3.3V –40 40 nA PG Pull-Down Resistance VPG = 0.1V l 750 2000 Ω SYNC/MODE Threshold SYNC/MODE DC and Clock Low Level Voltage l 0.7 0.9 V SYNC/MODE Clock High Level Voltage l 1.2 1.4 V SYNC/MODE DC High Level Voltage l 2.2 2.55 2.9 V Spread Spectrum Modulation RT = 60.4k, VSYNC = 3.3V 24 % Frequency Range Spread Spectrum Modulation Frequency VSYNC = 3.3V 2.5 kHz TR/SS Source Current l 1.2 1.9 2.6 µA TR/SS Pull-Down Resistance Fault Condition, TR/SS = 0.1V 220 Ω Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: θ values determined per JEDEC 51-7, 51-12. See Applications may cause permanent damage to the device. Exposure to any Absolute Information Section for information on improving the thermal resistance Maximum Rating condition for extended periods may affect device and for actual temperature measurements of a demo board in typical reliability and lifetime. operating conditions. Note 2: The LT8645SE/LT8646SE is guaranteed to meet performance Note 4: This IC includes overtemperature protection that is intended to specifications from 0°C to 125°C junction temperature. Specifications over protect the device during overload conditions. Junction temperature will the –40°C to 125°C operating junction temperature range are assured by exceed 150°C when overtemperature protection is active. Continuous design, characterization, and correlation with statistical process controls. operation above the specified maximum operating junction temperature The LT8645SI/LT8646SI is guaranteed over the full –40°C to 125°C will reduce lifetime. operating junction temperature range. The junction temperature (TJ, in °C) is calculated from the ambient temperature (TA in °C) and power dissipation (PD, in Watts) according to the formula: TJ = TA + (PD • θJA) where θJA (in °C/W) is the package thermal impedance. 8645Sfa 4 For more information www.linear.com/LT8645S