LTC3553-2_15 Datasheet, PDF (35/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger, Always-On LDO and Buck Regulator

PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
UD Package
20-Lead Plastic QFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1720 Rev A)
LTC3553-2
0.70 ±0.05
3.50 ± 0.05
(4 SIDES) 1.65 ± 0.05
2.10 ± 0.05
PACKAGE
OUTLINE
0.20 ±0.05
0.40 BSC
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
3.00 ± 0.10
(4 SIDES)
PIN 1
TOP MARK
(NOTE 6)
0.75 ± 0.05
R = 0.05
TYP
BOTTOM VIEW—EXPOSED PAD
R = 0.115
TYP
PIN 1 NOTCH
R = 0.20 TYP
OR 0.25 × 45°
CHAMFER
19 20
0.40 ± 0.10
1
2
1.65 ± 0.10
(4-SIDES)
0.200 REF
0.00 – 0.05
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
(UD20) QFN 0306 REV A
0.20 ± 0.05
0.40 BSC
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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