LTC3568 e lecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.3V, RT = 324k unless otherwise specified. (Note 2) fOSC Oscillator Frequency RT = 324k 0.85 1 1.15 MHz (Note 7) 4 MHz fSYNC Synchronization Frequency (Note 7) 0.4 4 MHz ILIM Peak Switch Current Limit ITH = 1.3 2.4 3 4 A RDS(ON) Top Switch On-Resistance (Note 6) VIN = 3.3V 0.11 0.15 Ω Bottom Switch On-Resistance (Note 6) VIN = 3.3V 0.11 0.15 Ω ISW(LKG) Switch Leakage Current VIN = 6V, VITH/RUN = 0V, VFB = 0V 0.01 1 µA VUVLO Undervoltage Lockout Threshold VIN Ramping Down 2 2.25 V PGOOD Power Good Threshold VFB Ramping Up, SHDN/RT = 1V 6.8 % VFB Ramping Down, SHDN/RT = 1V –7.6 % RPGOOD Power Good Pull-Down On-Resistance 118 200 Ω Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: Dynamic supply current is higher due to the internal gate charge may cause permanent damage to the device. Exposure to any Absolute being delivered at the switching frequency. Maximum Rating condition for extended periods may affect device Note 5: TJ is calculated from the ambient TA and power dissipation PD reliability and lifetime. according to the following formula: Note 2: The LTC3568 is tested under pulsed load conditions such that TJ = TJ = TA + (PD • 43°C/W) TA. The LTC3568E is guaranteed to meet performance specifications from Note 6: Switch on-resistance is guaranteed by correlation to wafer level 0°C to 85°C. Specifications over the –40°C to 125°C operating junction measurements. temperature range are assured by design, characterization and correlation with statistical process controls. The LTC3568I is guaranteed over the Note 7: 4MHz operation is guaranteed by design but not production tested full –40°C to 125°C operating junction temperature range. The maximum and is subject to duty cycle limitations (see Applications Information). ambient temperature is determined by specific operating conditions in Note 8: This IC includes overtemperature protection that is intended conjunction with board layout, the rated package thermal resistors and to protect the device during momentary overload conditions. Junction other environmental factors. temperature will exceed 125°C when overtemperature protection is active. Note 3: The LTC3568 is tested in a feedback loop which servos V Continuous operation above the specified maximum operating junction FB to the midpoint for the error amplifier (V temperature may impair device reliability. ITH = 0.6V). 3568fa 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 Revision History Typical Application Related Parts