Datasheet

LTC3785
18
3785fc
package DescripTion
UF Package
24-Lead Plastic QFN (4mm × 4mm)
(Reference LTC DWG # 05-08-1697)
Typical applicaTion
V
CC
I
SVIN
TG1V
SENSE
BG1FB
V
C
TG2
BG2
SW2
3785 TA02
V
BST1
SW1
I
SSW1
I
SVOUT
RT
V
DRV
I
SSW2
V
BST2
CCM
I
LSET
MODE
RUN/SS
V
IN
1nF
1nF
205k
270pF
1.3k
R1
205k
12k
R2
121k
R
T
59k
R
ILSET
42.2k
121k
LTC3785
GND
C
VCC
4.7µF
Li-Ion
2.7V TO 4.2V
MA = MB = MC = MD = 1/2 Si7940DY
L1 = WÜRTH ELECTRONICS 744311470
D1 = D2 = PMEG2020EJ
9V REGULATED
WALL ADAPTER
V
IN
2.7V TO 10V
V
OUT
3.3V
3A
C
IN
22µF
MA
MB
D1
D2
OPTIONAL
OPTIONAL
MD
MC
C
A
0.22µF
C
B
0.22µF
CMDSH-3
CMDSH-3
L1
4.7µH
C
OUT
100µF
+
4.00 ± 0.10
(4 SIDES)
NOTE:
1. DRAWING PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-X)—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, IF PRESENT
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
PIN 1
TOP MARK
(NOTE 6)
0.40 ± 0.10
2423
1
2
BOTTOM VIEW—EXPOSED PAD
2.45 ± 0.10
(4-SIDES)
0.75 ± 0.05
R = 0.115
TYP
0.25 ± 0.05
0.50 BSC
0.200 REF
0.00 – 0.05
(UF24) QFN 0105
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
0.70 ±0.05
0.25 ±0.05
0.50 BSC
2.45 ± 0.05
(4 SIDES)
3.10 ± 0.05
4.50 ± 0.05
PACKAGE
OUTLINE
PIN 1 NOTCH
R = 0.20 TYP OR
0.35 s 45° CHAMFER