LT1940/LT1940L WWWUUWUABSOLUTE AXI URATI GSPACKAGE/ORDER I FOR ATIO(Note 1) TOP VIEW ORDER PART VIN Voltage BOOST1 1 16 FB1 NUMBER LT1940 .. (–0.3), 25V LT1940L ... (–0.3), 7V SW1 2 15 VC1 LT1940EFE BOOST Pin Voltage V 3 14 IN PG1 LT1940LEFE V 4 13 RUN/SS1 LT1940 .. 35V IN 17 V 5 12 RUN/SS2 LT1940L ... 16V IN V 6 11 IN PG2 BOOST Pin Above SW Pin FE PART SW2 7 10 VC2 LT1940 .. 25V MARKING BOOST2 8 9 FB2 LT1940L ... 16V FE PACKAGE 1940EFE PG Pin Voltage 16-LEAD PLASTIC TSSOP 1940LEFE LT1940 .. 25V EXPOSED PAD (PIN 17) IS GND MUST BE SOLDERED TO PCB LT1940L ... 7V TJMAX = 125°C, θJA = 45°C/W, θJC = 10°C/W SW Voltage ..VIN Consult LTC Marketing for parts specified with wider operating temperature ranges. RUN/SS, FB Pins .. 6V Maximum Junction Temperature .. 125°C Operating Temperature Range (Note 2) ...–40°C to 85°C Storage Temperature Range ..–65°C to 150°C Lead Temperature (Soldering, 10 sec).. 300°C ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25 ° C. VIN = 5V, VBOOST = 8V unless otherwise noted. (Note 2)PARAMETERCONDITIONSMINTYPMAXUNITS Minimum Operating Voltage ● 3.4 3.6 V Quiescent Current Not Switching 3.8 4.8 mA Shutdown Current VRUNSS = 0V 30 45 µA Feedback Voltage 1.230 1.250 1.270 V 0°C to 70°C ● 1.225 1.250 1.270 V –40°C to 85°C ● 1.215 1.250 1.270 V FB Pin Bias Current VFB = 1.25V, VC = 0.4V ● 240 1200 nA Reference Line Regulation LT1940: VIN 5V to 25V 0.005 %/V LT1940L: VIN 4V to 7V 0.005 %/V Error Amp GM 330 uMhos Error Amp Voltage Gain 180 VC Source Current VFB = 1V 42 µA VC Sink Current VFB = 1.5V 60 µA VC Pin to Switch Current Gain 2.4 A/V VC Switching Threshold 0.75 V VC Clamp Voltage 1.8 V Switching Frequency VFB = 1.1V 1 1.1 1.25 MHz ● 0.95 1.1 1.35 MHz Switching Phase 150 180 210 Deg Maximum Duty Cycle ● 78 88 % Frequency Shift Threshold on FB fSW = 1MHz 0.5 V 1940fa 2