LTC3108-1
BLOCK DIAGRAM
LTC3108-1
1.3Ω
ILIM
V
OUT2_EN
SYNC RECTIFY
C1
V
IN
C
IN
C2
C2
SW
SW
V
OUT
VSTORE
0.5Ω
CHARGE
CONTROL
V
REF
VLDO
1M
1:100
C1
5.25V
REFERENCE
1.2V
V
REF
V
OUT2
V
OUT2
OFF ON
5M
V
OUT
V
OUT
C
OUT
+
–
VS1
VS2
V
OUT
PROGRAM
–
+
VAUX
1μF
V
OUT
GND (SSOP)
V
BEST
V
REF
LDO
VLDO
PGD
PGOOD
VSTORE
C
STORE
31081 BD
EXPOSED PAD (DFN)
2.2V
2.2μF
OPERATION
(Refer to the Block Diagram)
The LTC3108-1 is designed to use a small external step-up
transformer to create an ultralow input voltage step-up
DC/DC converter and power manager. It is ideally suited
for low power wireless sensors and other applications in
which surplus energy harvesting is used to generate system
power because traditional battery power is inconvenient
or impractical.
The LTC3108-1 is designed to manage the charging and
regulation of multiple outputs in a system in which the
average power draw is very low, but there may be periodic
pulses of higher load current required. This is typical of
wireless sensor applications, where the quiescent power
draw is extremely low most of the time, except for transmit
bursts when circuitry is powered up to make measure-
ments and transmit data.
The LTC3108-1 can also be used to trickle charge a standard
capacitor, supercapacitor or rechargeable battery, using
energy harvested from a Peltier or photovoltaic cell.
31081fa
8
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
