Datasheet LT1944 (Analog Devices) - 2

LT1944
W W W U U W U ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1)
ORDER PART V TOP VIEW IN, SHDN1, SHDN2 Voltage ... 15V NUMBER FB1 1 10 SW1 SW1, SW2 Voltage .. 36V SHDN1 2 9 PGND GND 3 8 VIN LT1944EMS FB1, FB2 Voltage ...VIN SHDN2 4 7 PGND Current into FB1, FB2 Pins ... 1mA FB2 5 6 SW2 Junction Temperature ... 125°C MS10 PACKAGE MS10 PART 10-LEAD PLASTIC MSOP Operating Temperature Range (Note 2) .. – 40°C to 85°C MARKING Storage Temperature Range ... – 65°C to 150°C TJMAX = 125°C, θJA = 160°C/W LTTR Lead Temperature (Soldering, 10 sec).. 300°C Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 1.2V, VSHDN = 1.2V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage 1.2 V Quiescent Current, Each Switcher Not Switching 20 30 µA VSHDN = 0V 1 µA FB Comparator Trip Point ● 1.205 1.23 1.255 V FB Comparator Hysteresis 8 mV FB Voltage Line Regulation 1.2V < VIN < 12V 0.05 0.1 %/V FB Pin Bias Current (Note 3) VFB = 1.23V ● 30 80 nA Switch Off Time VFB > 1V 400 ns VFB < 0.6V 1.5 µs Switch VCESAT ISW = 300mA 250 350 mV Switch Current Limit 250 350 400 mA SHDN Pin Current VSHDN = 1.2V 2 3 µA VSHDN = 5V 8 12 µA SHDN Input Voltage High 0.9 V SHDN Input Voltage Low 0.25 V Switch Leakage Current Switch Off, VSW = 5V 0.01 5 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
Note 2:
The LT1944 is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3:
Bias current flows into the FB pin. 2