Datasheet LT1945 (Analog Devices) - 2

LT1945
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1)
TOP VIEW VIN, SHDN1, SHDN2 Voltage ...15V NFB1 1 10 SW1 SW1, SW2 Voltage ..36V SHDN1 2 9 PGND GND 3 8 V NFB1 Voltage ..–3V IN SHDN2 4 7 PGND FB2 Voltage ... VIN FB2 5 6 SW2 Current into NFB1 Pin ..–1mA MS PACKAGE 10-LEAD PLASTIC MSOP Current into FB2 Pin ..1mA TJMAX = 125°C, θJA = 160°C/W 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
ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1945EMS#PBF LT1945EMS#TRPBF LTTS 10-Lead Plastic MSOP –40°C to 85°C LT1945IMS#PBF LT1945IMS#TRPBF LTTS 10-Lead Plastic MSOP –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1945EMS LT1945EMS#TR LTTS 10-Lead Plastic MSOP –40°C to 85°C LT1945IMS LT1945IMS#TR LTTS 10-Lead Plastic MSOP –40°C to 125°C Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations 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, (per Converter) Not Switching 20 30 μA VSHDN = 0V 1 μA NFB1 Comparator Trip Point –40°C < TJ < 85°C –1.205 –1.23 –1.255 V –40°C < TJ < 125°C –1.195 1.255 V FB2 Comparator Trip Point –40°C < TJ < 85°C 1.205 1.23 1.255 V –40°C < TJ < 125°C 1.195 1.255 V FB Comparator Hysteresis 8 mV NFB1, FB2 Voltage Line Regulation 1.2V < VIN < 12V 0.05 0.1 %/V NFB1 Pin Bias Current (Note 3) VNFB1= –1.23V l 1.3 2 2.9 μA FB2 Pin Bias Current (Note 4) –40°C < TJ < 85°C 30 80 nA –40°C < TJ < 125°C 300 nA Switch Off Time, Switcher 1 (Note 5) 400 ns Switch Off Time, Switcher 2 (Note 5) VFB2 > 1V 400 ns VFB2 < 0.6V 1.5 μs Switch VCESAT ISW = 300mA 250 350 mV Switch Current Limit 250 350 400 mA 1945fa 2