UFE Package 38-Lead Plastic QFN (4mm × 6mm) (Reference LTC DWG # 05-08-1750 Rev B) 0.70 ±0.05 4.50 ± 0.05 3.10 ± 0.05 2.40 REF 2.65 ± 0.05 4.65 ± 0.05 PACKAGE OUTLINE 0.20 ±0.05 0.40 BSC 4.40 REF 5.10 ± 0.05 6.50 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ± 0.10 0.75 ± 0.05 R = 0.10 TYP PIN 1 NOTCH R = 0.30 OR 0.35 × 45° CHAMFER 2.40 REF 37 38 0.40 ± 0.10 PIN 1 TOP MARK (NOTE 6) 1 2 4.65 ± 0.10 6.00 ± 0.10 4.40 REF 2.65 ± 0.10 (UFE38) QFN 0708 REV B 0.200 REF 0.00 – 0.05 R = 0.115 TYP 0.20 ± 0.05 0.40 BSC BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE