LTC3459ES6TRMPBF Datasheet, PDF (10/12 Pages) Linear Technology – 10V Micropower Synchronous Boost Converter

LTC3459
TYPICAL APPLICATIONS
controlled, preventing any damaging effects of inrush
current. Proper heat sinking of the package is required in
this application as the die may dissipate 100mW to 200mW
during initial charging. When V_OUT is greater than ~3.5V,
normal boost mode operation and efficiency begin, with
the P-channel MOSFET acting as a synchronous switch.
Average input current is a constant 50mA during charg-
ing, where the current delivered to the SuperCap varies
somewhat with duty cycle. Once the SuperCap is charged
to 5V, the LTC3459 begins to regulate and the input cur-
rent is reduced to the amount required to support the load
and/or self discharge of the SuperCap.
L1
+
3.3V
1μF
OFF ON
SW
V_IN
V_OUT
LTC3459
SHDN FB
GND
1M
332k
V_OUT
5V
1μF
C_OUT
2F
3459 F05
C_OUT: MAXWELL TECHNOLOGIES ULTRACAP PC5-5, 2F, 5V
L1: 33μH, 1.7Ω TAIYO YUDEN LB2016
Figure 5. Charging a SuperCap from a 3.3V Source
PACKAGE DESCRIPTION
DC Package
6-Lead Plastic DFN (2mm × 2mm)
(Reference LTC DWG # 05-08-1703)
0.675 p0.05
R = 0.115
TYP
0.56 p 0.05
4
(2 SIDES)
0.38 p 0.05
6
2.50 p0.05
1.15
p0.05
0.61 p0.05
(2 SIDES)
PACKAGE ^{PIN 1 BAR}
OUTLINE ^{TOP MARK}
(SEE NOTE 6)
0.25 p 0.05
0.50 BSC
1.42 p0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
0.200 REF
2.00 p0.10
(4 SIDES)
0.75 p0.05
0.00 – 0.05
PIN 1
CHAMFER OF
EXPOSED PAD
3
1
(DC6) DFN 1103
0.25 p 0.05
0.50 BSC
1.37 p0.05
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WCCD-2)
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
3459fc
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