UF Package 20-Lead Plastic QFN (4mm × 4mm) (Reference LTC DWG # 05-08-1710 Rev A) 0.70 0.05 4.50 0.05 3.10 0.05 2.00 REF 2.45 0.05 2.45 0.05 PACKAGE OUTLINE 0.25 0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 0.10 0.75 0.05 BOTTOM VIEW—EXPOSED PAD R = 0.05 TYP R = 0.115 TYP 19 20 0.40 0.10 PIN 1 TOP MARK (NOTE 6) 4.00 0.10 PIN 1 NOTCH R = 0.20 TYP OR 0.35 ¥ 45 CHAMFER 1 2.00 REF 2.45 0.10 2 2.45 0.10 (UF20) QFN 01-07 REV A 0.200 REF 0.00 – 0.05 NOTE: 1. DRAWING IS PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-1)—TO BE APPROVED 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 0.25 0.05 0.50 BSC