Datasheet LT3509 (Analog Devices) - 3

LT3509
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. (Note 3) PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Undervoltage Lockout 3.3 3.6 V VIN Overvoltage Lockout 37 38.5 40 V Input Quiescent Current Not Switching VFB > 0.8V 1.9 2.2 mA Input Shutdown Current V(RUN/SS[1,2]) < 0.3V 9 15 µA Feedback Pin Voltage l 0.784 0.8 0.816 V Reference Voltage Line Regulation 3.6V < VIN < 36V 0.01 %/V RUN/SS Shutdown Threshold 0.4 0.6 0.8 V RUN/SS Voltage for Full IOUT 2 V RUN/SS Pin Pull-up Current 0.7 1 1.3 µA Feedback Pin Bias Current (Note 4) VFB = 0.8V l 90 500 nA Switch Current Limit l 1.05 1.4 1.9 A DA Comparator Current Threshold 0.7 0.95 1.2 A Boost Pin Current ISW = 0.9A 22 36 mA Switch Leakage Current 0.01 1.0 µA Switch Saturation Voltage ISW = 0.9A (Note 5) 0.32 V Minumum Boost Voltage above Switch ISW = 0.9A 1.5 2.2 V Boost Diode Forward Voltage IBD= 20mA 0.7 0.9 V Boost Diode Leakage VR = 30V 0.1 5 µA Switching Frequency RT = 40.2kΩ l 0.92 1.0 1.08 MHz RT = 180kΩ 237 260 290 kHz RT = 14.1kΩ 2.0 2.15 2.5 MHz Sync Pin Input Threshold 1.0 V Switch Minimum Off-Time l 80 150 ns
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings over the full –40°C to 150°C operating junction temperature range. High may cause permanent damage to the device. Exposure to any Absolute junction temperatures degrade operating lifetimes. Operating lifetime is Maximum Rating condition for extended periods may affect device reliability derated at junction temperatures greater than 125°C. and lifetime.
Note 4.
Current flows out of pin.
Note 2
. Absolute Maximum Voltage at the VIN pin is 60V for non-repetitive
Note 5
. Switch Saturation Voltage is guaranteed by design. 1 second transients and 36V for continuous operation.
Note 6.
This IC includes overtemperature protection that is intended to protect
Note 3.
The LT3509E is guaranteed to meet performance specifications from the device during momentary overload conditions. Junction temperature will 0°C to 125°C junction temperature. Specifications over the –40°C to 125°C exceed the maximum operating temperature when overtemperature protection operating junction temperature range are assured by design, characterization is active. Continuous operation above the specified maximum operating and correlation with statistical process controls. The LT3509I is guaranteed junction temperature may impair device reliability. over the full –40°C to 125°C temperature range. The LT3509H is guaranteed 3509fd For more information www.linear.com/LT3509 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Related Parts