LTC3646/LTC3646-1 ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the specified operatingjunction temperature range, otherwise specifications are at TA = 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS tPGOOD PGOOD Filter Time RT = INTVCC 15 30 µs RPGOOD PGOOD Pull-Down Resistance IPGOOD = 10mA 63 Ω PGOOD Leakage VPGOOD = VINTVCC 1.0 µA tSS Internal Soft-Start Time 250 500 µs VMODE/SYNC Mode Threshold Voltage Mode VIH l 1.2 V Mode VIL l 0.3 V SYNC Threshold Voltage SYNCIH l 1.2 V SYNCIL l 0.3 V MODE/SYNC Input Current 1 2 µA Internal ITH Voltage Threshold l INTVCC – 0.3V V VON Pin Input Impedance LTC3646 520 kΩ LTC3646-1 600 kΩ Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: Dynamic supply current is higher due to gate charging being may cause permanent damage to the device. Exposure to any Absolute delivered at the switch frequency. Maximum Rating condition for extended periods may affect device Note 4: Limits to VOUT are a subject to PVIN, SVIN, tON(MIN), tOFF(MIN), reliability and lifetime. and frequency constraints. See the Applications Information section for a Note 2: The LTC3646 is tested under pulsed load conditions such that further discussion. These items are tested with appropriate combinations TJ ≈ TA. The LTC3646E is guaranteed to meet specifications from of VIN, VON and frequency. 0°C to 85°C junction temperature. Specifications over the –40°C to Note 5: RDS(ON) is guaranteed by correlation to wafer level measurements. 125°C operating junction temperature range are assured by design, Note 6: Maximum allowed current draw when used as a regulated output characterization and correlation with statistical process controls. The is 5mA. This supply is only intended to provide additional DC load current LTC3646I is guaranteed over the –40°C to 125°C operating junction as needed and not to regulate large transient or AC behavior as such temperature range and the LTC3646H is guaranteed over the –40°C to waveforms may impact LTC3646 operation. 150°C operating junction temperature range. High junction temperatures derate operating lifetimes; operating lifetime is derated for junction Note 7: This IC includes overtemperature protection intended to protect temperatures greater than 125°C. Note that the maximum ambient the device during momentary overload conditions. The maximum junction temperature consistent with these specifications is determined by specific temperature may be exceeded when overtemperature protection is active. operating conditions in conjunction with board layout, the rated package Continuous operation above the specified maximum operating junction thermal impedance and other environmental factors. temperature may result in device degradation or failure. 36461fc 4 For more information www.linear.com/LTC3646 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Operation Applications Information Typical Applications Typical Application Related Parts