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LTC3109_12 Datasheet, PDF (1/24 Pages) Linear Technology – Auto-Polarity, Ultralow Voltage Step-Up Converter | |||
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FEATURES
n Operates from Inputs as Low as ±30mV
n Less Than ±1°C Needed Across TEG to Harvest
Energy
n Proprietary Auto-Polarity Architecture
n Complete Energy Harvesting Power Management
System
â Selectable VOUT of 2.35V, 3.3V, 4.1V or 5V
â 2.2V, 5mA LDO
â Logic-Controlled Output
â Energy Storage Capability for Operation During
Power Interruption
n Power Good Indicator
n Uses Compact Step-up Transformers
n Small, 20-lead (4mm à 4mm) QFN Package or
20-Lead SSOP
APPLICATIONS
n Remote Sensor and Radio Power
n HVAC Systems
n Automatic Metering
n Building Automation
n Predictive Maintenance
n Industrial Wireless Sensing
LTC3109
Auto-Polarity, Ultralow
Voltage Step-Up Converter
and Power Manager
DESCRIPTION
The LTC®3109 is a highly integrated DC/DC converter ideal
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.
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, while the main output can be programmed
to one of four ï¬xed 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 efï¬ciency maximizes the harvested
energy available for the application.
The LTC3109 is available in a small, thermally enhanced
20-lead (4mm à 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.
TYPICAL APPLICATION
TEG
(THERMOELECTRIC GENERATOR)
±30mV TO ±500mV
1:100
â¢â¢
47μF
1:100
â¢â¢
1nF
470pF
1nF
470pF
C1A
VOUT2
C2A
VOUT
SWA VLDO
VINA
LTC3109
C1B
C2B PG00D
OPTIONAL SWITCHED OUTPUT FOR SENSORS
3.3V
2.2V
2.2μF
+
470μF
LOW POWER
RADIO
μP
SENSOR(S)
VAUX
SWB
VINB
VS1
VS2
VOUT2_EN
VSTORE
VAUX
GND
5.25V
+
1μF
CSTORE
3109 TA01a
VOUT Current vs TEG Voltage
900
1:100 TRANSFORMERS
800
C1A = C1B = 1nF
VOUT = 3.3V
700
600
500
400
300
200
100
0
â300 â200 â100 0 100
VTEG (mV)
200 300
3109 TA01b
3109fa
1
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