LTC3109_15 Datasheet, PDF (1/24 Pages) Linear Technology – Auto-Polarity, Ultralow Voltage Step-Up Converter and Power Manager

LTC3109
Features
Auto-Polarity, Ultralow
Voltage Step-Up Converter
and Power Manager
Description
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
– Selectable V_OUT of 2.35V, 3.3V, 4.1V or 5V
– 2.2V, 5mA LDO
– Logic-Controlled Output
– Energy Storage Capability for Operation During
Power Interruption
n _{Power Good Indicator}
n _{Uses Compact Step-up Transformers}
n _{Small, 20-lead (4mm × 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}
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 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.
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.
Typical Application
TEG
(THERMOELECTRIC GENERATOR)
±30mV TO ±500mV
1:100
••
47µF
1:100
••
1nF
470pF
1nF
470pF
C1A
V_OUT2
C2A
V_OUT
SWA VLDO
V_INA
LTC3109
C1B
C2B PG00D
OPTIONAL SWITCHED OUTPUT FOR SENSORS
3.3V
2.2V
2.2µF
+
470µF
LOW POWER
RADIO
µP
SENSOR(S)
VAUX
SWB
V_INB
VS1
VS2
V_{OUT2_EN}
VSTORE
VAUX
GND
5.25V
+
1µF
C_STORE
3109 TA01a
For more information www.linear.com/LTC3109
V_OUT Current vs TEG Voltage
900
1:100 TRANSFORMERS
800
C1A = C1B = 1nF
V_OUT = 3.3V
700
600
500
400
300
200
100
0
–300 –200 –100 0 100
V_TEG (mV)
200 300
3109 TA01b
3109fb
1