LTC3899 ELECTRICAL CHARACTERISTICSNote 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: This IC includes overtemperature protection that is intended to may cause permanent damage to the device. Exposure to any Absolute protect the device during momentary overload conditions. The maximum Maximum Ratings for extended periods may affect device reliability and rated junction temperature will be exceeded when this protection is active. lifetime. Continuous operation above the specified absolute maximum operating Note 2: The LTC3899 is tested under pulsed load conditions such that junction temperature may impair device reliability or permanently damage T the device. J ≈ TA. The LTC3899E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 125°C operating Note 4: The LTC3899 is tested in a feedback loop that servos VITH1,2,3 to a junction temperature range are assured by design, characterization and specified voltage and measures the resultant VFB1,2,3. The specification at correlation with statistical process controls. The LTC3899I is guaranteed 85°C is not tested in production and is assured by design, characterization over the –40°C to 125°C operating junction temperature range, the and correlation to production testing at other temperatures (125°C for LTC3899H is guaranteed over the –40°C to 150°C operating junction the LTC3899E and LTC3899I, 150°C for the LTC3899H and LTC3899MP). temperature range, and the LTC3899MP is tested and guaranteed over For the LTC3899I and LTC3899H, the specification at 0°C is not tested in the –55°C to 150°C operating junction temperature range. High junction production and is assured by design, characterization and correlation to temperatures degrade operating lifetimes; operating lifetime is derated production testing at –40°C. For the LTC3899MP, the specification at 0°C for junction temperatures greater than 125°C. Note that the maximum is not tested in production and is assured by design, characterization and ambient temperature consistent with these specifications is determined by correlation to production testing at –55°C. specific operating conditions in conjunction with board layout, the rated Note 5: Dynamic supply current is higher due to the gate charge being package thermal impedance and other environmental factors. The junction delivered at the switching frequency. See Applications information. temperature (TJ, in °C) is calculated from the ambient temperature Note 6: Rise and fall times are measured using 10% and 90% levels. Delay (TA, in °C) and power dissipation (PD, in Watts) according to the formula: times are measured using 50% levels TJ = TA + (PD • θJA) Note 7: The minimum on-time condition is specified for an inductor where θJA = 34°C/W for the QFN package and where θJA = 25°C/W for the peak-to-peak ripple current >40% of IMAX (See Minimum On-Time TSSOP package. Considerations in the Applications Information section). Note 8: Do not apply a voltage or current source to these pins. They must be connected to capacitive loads only, otherwise permanent damage may occur. 3899fa 6 For more information www.linear.com/LTC3899 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagrams Operation Typical Applications Package Description Typical Application Related Parts