UFD Package Variation: UFD28MA 28-Lead Plastic QFN (4mm × 5mm) (Reference LTC DWG # 05-08-1866 Rev Ø) 0.45 REF 0.70 ±0.05 4.50 ± 0.05 3.10 ± 0.05 2.49 ± 0.05 2.49 ± 0.05 1.73 ±0.05 1.73 ±0.05 2.50 REF PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 3.50 REF 4.10 ± 0.05 5.50 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ± 0.10 (2 SIDES) 0.75 ± 0.05 R = 0.05 TYP PIN 1 NOTCH R = 0.20 OR 0.35 × 45° CHAMFER 2.50 REF R = 0.125 TYP 27 28 0.40 ± 0.10 PIN 1 TOP MARK (NOTE 6) 1 2 1.73 ± 0.10 5.00 ± 0.10 (2 SIDES) 3.50 REF 0.45 REF 1.73 ± 0.10 2.49 ± 0.10 (UFD28MA) QFN 0210 REV Ø 0.200 REF 0.00 – 0.05 0.25 ± 0.05 0.50 BSC BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WXXX-X). 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