LTC3109
Auto-Polarity, Ultralow
Voltage Step-Up Converter
and Power Manager
DescripTion
TheLTC®3109isahighlyintegratedDC/DCconverterideal
for harvesting surplus energy from extremely low input
voltage sources such as TEGs (thermoelectric genera-
tors) and thermopiles. Its unique, proprietary autopolarity
topology* allows it to operate from input voltages as low
as 30mV, regardless of polarity.
FeaTures
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Operates from Inputs as Low as ±±3mV
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Less Than ±ꢀ1C ꢁeeꢂeꢂ ꢃAross TEG to ꢄarvest
Energy
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Proprietary ꢃuto-Polarity ꢃrAhiteAture
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Complete Energy ꢄarvesting Power Management
System
– SeleAtable V
of 2.±5V, ±.±V, 4.ꢀV or 5V
OUT
Using two compact step-up transformers and external
energy storage elements, the LTC3109 provides a com-
plete power management solution for wireless sensing
and data acquisition. The 2.2V LDO can power an external
microprocessor,whilethemainoutputcanbeprogrammed
to one of four fixed voltages. The power good indicator
signals that the main output is within regulation. A second
output can be enabled by the host. A storage capacitor (or
battery) can also be charged to provide power when the
input voltage source is unavailable. Extremely low quies-
cent current and high efficiency maximizes the harvested
energy available for the application.
– 2.2V, 5mꢃ LDO
– LogiA-Controlleꢂ Output
– Energy Storage Capability for Operation During
Power Interruption
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Power Gooꢂ InꢂiAator
Uses Compact Step-up Transformers
Small, 20-lead (4mm × 4mm) QFN Package or
20-Lead SSOP
applicaTions
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Remote Sensor and Radio Power
The LTC3109 is available in a small, thermally enhanced
20-lead (4mm × 4mm) QFN package and a 20-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.
*Patent pending.
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HVAC Systems
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Automatic Metering
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Building Automation
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Predictive Maintenance
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Industrial Wireless Sensing
Typical applicaTion
TEG
(THERMOELECTRIC GENERATOR)
1nF
VOUT Current vs TEG Voltage
30ꢀV TO 500ꢀV
1:100
C1A
V
OPTIONAL SWITCHED OUTPUT FOR SENSORS
OUT2
•
•
900
800
700
600
500
400
300
200
100
1:100 TRANSFORMERS
C1A = C1B = 1nF
470pF
3.3V
2.2V
C2A
V
47µF
OUT
V
= 3.3V
OUT
+
470µF
SWA
VLDO
2.2µF
V
LOW POWER
RADIO
INA
1nF
LTC3109
1:100
C1B
•
•
SENSOR(S)
µP
470pF
C2B
PG00D
SWB
V
OUT2_EN
V
INB
5.25V
VS1
VS2
VAUX
VSTORE
VAUX
0
+
–300 –200 –100
0
300
100
200
1µF
C
STORE
GND
V
(mV)
TEG
3109 TA01a
3109 TA01b
3109f
ꢀ