LT3957A ABSOLUTE MAXIMUM RATINGSPIN CONFIGURATION(Note 1) V TOP VIEW IN, EN/UVLO (Note 5), SW ..40V INTVCC ..VIN + 0.3V, 8V C SYNC ..8V NC NC SYNC RT SS FBX V 36 35 34 33 32 31 30 VC, SS ...3V NC 1 28 INTVCC RT ..1.5V NC 2 27 VIN SENSE1, SGND... Internally Connected to GND SENSE2 3 SGND SENSE2 ..±0.3V 37 SGND 4 25 EN/UVLO FBX ... –6V to 6V 24 SGND Operating Junction Temperature Range SENSE1 6 23 SGND (Note 2) .. –40°C to 125°C SW SW 8 21 SW Maximum Junction Temperature .. 125°C 38 SW 9 20 SW Storage Temperature Range .. –65°C to 125°C NC 10 12 13 14 15 16 17 GND GND GND GND GND GND UHE PACKAGE 36-LEAD (5mm w 6mm) PLASTIC QFN TJMAX = 125°C, θJA = 42°C/W, θJC = 3°C/W EXPOSED PAD (PIN 37) IS SGND, MUST BE SOLDERED TO SGND PLANE EXPOSED PAD (PIN 38) IS SW, MUST BE SOLDERED TO SW PLANE ORDER INFORMATIONLEAD FREE FINISHTAPE AND REELPART MARKING*PACKAGE DESCRIPTIONTEMPERATURE RANGE LT3957AEUHE#PBF LT3957AEUHE#TRPBF 3957A 36-Lead (5mm × 6mm) Plastic QFN –40°C to 125°C LT3957AIUHE#PBF LT3957AIUHE#TRPBF 3957A 36-Lead (5mm × 6mm) Plastic QFN –40°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified 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 specifications, go to: http://www.linear.com/tapeandreel/ 3957afa 2