LT1944-1 WWWUUWUABSOLUTE AXI URATI GSPACKAGE/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 LT1944-1EMS 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 LTTU 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 operatingtemperature range, otherwise specifications are at TA = 25 ° C. VIN = 1.2V, VSHDN = 1.2V unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITS 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, Switcher 1 (Note 4) VFB > 1V 400 ns VFB < 0.6V 1.5 µs Switch Off Time, Switcher 2 (Note 4) VFB > 1V 1.5 µs VFB < 0.6V 1.5 µs Switch VCESAT ISW = 70mA 85 120 mV Switch Current Limit, Switcher 1 65 100 125 mA Switch Current Limit, Switcher 2 130 175 225 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 temperature range are assured by design, characterization and correlation of a device may be impaired. with statistical process controls. Note 2: The LT1944-1E is guaranteed to meet performance specifications Note 3: Bias current flows into the FB pin. from 0°C to 70°C. Specifications over the – 40°C to 85°C operating Note 4: See Figure 1 for Switcher 1 and Switcher 2 locations. 2