LTC3108
Ultralow Voltage Step-Up
Converter and Power Manager
Features
Description
Operates from Inputs of 20mV
n Complete Energy Harvesting Power
Management System
- Selectable VOUT of 2.35V, 3.3V, 4.1V or 5V
- LDO: 2.2V at 3mA
- Logic Controlled Output
- Reserve Energy Output
n Power Good Indicator
n Uses Compact Step-Up Transformers
n Small 12-Lead (3mm × 4mm) DFN or 16-Lead
SSOP Packages
The LTC®3108 is a highly integrated DC/DC converter ideal
for harvesting and managing surplus energy from extremely
low input voltage sources such as TEGs (thermoelectric
generators), thermopiles and small solar cells. The step-up
topology operates from input voltages as low as 20mV.
The LTC3108 is functionally equivalent to the LTC3108-1
except for its unique fixed VOUT options.
n
Using a small step-up transformer, the LTC3108 provides a
complete power management solution for wireless sensing
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
or sensors. The power good indicator signals that the main
output voltage is within regulation. A second output can be
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
Surplus Heat Energy Harvesting
HVAC Systems
Industrial Wireless Sensing
Automatic Metering
Building Automation
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
THERMOELECTRIC
GENERATOR
+
220µF
C1
VSTORE
+
LTC3108
330pF
1000
100
PGOOD
PGD
2.2V
VLDO
SW
µP
2.2µF SENSORS
VOUT
VS2
VS1 VOUT2_EN
VAUX
GND
3.3V
+
VOUT = 3.3V
COUT = 470µF
0.1F
6.3V
VOUT2
C2
20mV TO 500mV
5V
VOUT Charge Time
470µF
RF LINK
TIME (sec)
1:100
+
1nF
10
1
1:100 Ratio
1:50 Ratio
1:20 Ratio
3108 TA01a
1µF
0
0
50
100 150 200 250 300 350 400
VIN (mV)
3108 TA01b
3108fc
For more information www.linear.com/LTC3108
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