LTC3108
Ultralow Voltage Step-Up
Converter and Power Manager
FeaTures
DescripTion
TheLTC®3108isahighlyintegratedDC/DCconverterideal
forharvestingandmanagingsurplusenergyfromextremely
low input voltage sources such as TEGs (thermoelectric
generators),thermopilesandsmallsolarcells.Thestep-up
topology operates from input voltages as low as 20mV.
The LTC3108 is functionally equivalent to the LTC3108-1
n
Operates from Inputs of 20mV
n
Complete Energy Harvesting Power
Management System
- Selectable V
of 2.35V, 3.3V, 4.1V or 5V
OUT
- LDO: 2.2V at 3mA
- Logic Controlled Output
- Reserve Energy Output
Power Good Indicator
Uses Compact Step-Up Transformers
Small 12-Lead (3mm × 4mm) DFN or 16-Lead
SSOP Packages
except for its unique fixed V
options.
OUT
n
n
n
Usingasmallstep-uptransformer,theLTC3108providesa
completepowermanagementsolutionforwirelesssensing
and data acquisition. The 2.2V LDO powers an external
microprocessor, while the main output is programmed to
one of four fixed voltages to power a wireless transmitter
orsensors.Thepowergoodindicatorsignalsthatthemain
outputvoltageiswithinregulation.Asecondoutputcanbe
enabled by the host. A storage capacitor provides power
when the input voltage source is unavailable. Extremely
low quiescent current and high efficiency design ensure
the fastest possible charge times of the output reservoir
capacitor.
applicaTions
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Remote Sensors and Radio Power
n
Surplus Heat Energy Harvesting
n
HVAC Systems
n
Industrial Wireless Sensing
n
Automatic Metering
n
Building Automation
n
Predictive Maintenance
The LTC3108 is available in a small, thermally enhanced
12-lead (3mm × 4mm) DFN package and a 16-lead SSOP
package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion
Wireless Remote Sensor Application Powered From a Peltier Cell
VOUT Charge Time
1nF
1:100
5V
1000
100
10
1
C1
VSTORE
LTC3108
V
C
= 3.3V
= 470µF
+
+
OUT
OUT
+
0.1F
6.3V
THERMOELECTRIC
GENERATOR
220µF
330pF
V
OUT2
PGD
VLDO
C2
PGOOD
2.2V
µP
20mV TO 500mV
SW
2.2µF
SENSORS
RF LINK
3.3V
VS2
V
OUT
+
470µF
1:100 Ratio
1:50 Ratio
1:20 Ratio
VS1
V
OUT2_EN
GND
3108 TA01a
VAUX
0
100 150 200 250 300 350 400
(mV)
0
50
1µF
V
IN
3108 TA01b
3108fa
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