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.
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Operates from Inputs as Low as ±30mV
Less Than ±1°C Needed Across TEG to Harvest
Energy
Proprietary Auto-Polarity Architecture
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
Power Good Indicator
Uses Compact Step-up Transformers
Small, 20-lead (4mm
×
4mm) QFN Package or
20-Lead SSOP
applicaTions
n
n
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Remote Sensor and Radio Power
HVAC Systems
Automatic Metering
Building Automation
Predictive Maintenance
Industrial Wireless Sensing
Typical applicaTion
TEG
(THERMOELECTRIC GENERATOR)
±30mV TO ±500mV
1:100
1nF
•
•
C1A
470pF
C2A
SWA
V
INA
C1B
470pF
C2B
V
OUT2
V
OUT
VLDO
OPTIONAL SWITCHED OUTPUT FOR SENSORS
3.3V
2.2V
2.2µF
V
OUT
Current vs TEG Voltage
900
800
1:100 TRANSFORMERS
C1A = C1B = 1nF
V
OUT
= 3.3V
47µF
+
470µF
700
LOW POWER
RADIO
600
I
VOUT
(µA)
500
400
300
200
•
1:100
1nF
LTC3109
µP
PG00D
•
SENSOR(S)
VAUX
SWB V
OUT2_EN
V
INB
VS1
VSTORE
VAUX
VS2
GND
5.25V
1µF
100
+
C
STORE
3109 TA01a
0
–300
–200
–100
0
100
V
TEG
(mV)
200
300
3109 TA01b
3109fb
For more information
www.linear.com/LTC3109
1
LTC3109
absoluTe MaxiMuM raTings
(Note 1)
SWA, SWB, V
INA
, V
INB
Voltage .................... –0.3V to 2V
C1A, C1B Voltage ......................................... –0.3V to 6V
C2A, C2B Voltage (Note 6) .............................. –8V to 8V
V
OUT2
, V
OUT2_EN
.......................................... –0.3V to 6V
VS1, VS2, V
OUT
, PGOOD .............................. –0.3V to 6V
VLDO, VSTORE ............................................ –0.3V to 6V
VAUX...................................................... 15mA Into V
AUX
Operating Junction Temperature Range
(Note 2) .................................................. –40°C to 125°C
Storage Temperature Range .................. –65°C to 125°C
pin conFiguraTion
TOP VIEW
GND
VS2
VS1
C1A
C2A
20 19 18 17 16
VSTORE 1
VAUX 2
V
OUT
3
V
OUT2
4
V
OUT2_EN
5
6
PGOOD
7
VLDO
8
GND
9 10
C1B
C2B
21
GND
15 SWA
14 V
INA
13 V
INB
12 SWB
11 GND
VS1
VS2
VSTORE
VAUX
V
OUT
V
OUT2
V
OUT2_EN
PGOOD
VLDO
1
2
3
4
5
6
7
8
9
TOP VIEW
20 C1A
19 C2A
18 GND
17 SWA
16 V
INA
15 V
INB
14 SWB
13 GND
12 C2B
11 C1B
GND 10
UF PACKAGE
20-LEAD (4mm
×
4mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 37°C/W
EXPOSED PAD (PIN 21) IS GND (Note 5)
GN PACKAGE
20-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 90°C/W
orDer inForMaTion
LEAD FREE FINISH
LTC3109EUF#PBF
LTC3109IUF#PBF
LTC3109EGN#PBF
LTC3109IGN#PBF
TAPE AND REEL
LTC3109EUF#TRPBF
LTC3109IUF#TRPBF
LTC3109EGN#TRPBF
LTC3109IGN#TRPBF
PART MARKING*
3109
3109
LTC3109GN
LTC3109GN
PACKAGE DESCRIPTION
20-Lead (4mm
×
4mm) Plastic QFN
20-Lead (4mm
×
4mm) Plastic QFN
20-Lead Plastic SSOP
20-Lead Plastic SSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
2
3109fb
For more information
www.linear.com/LTC3109
LTC3109
elecTrical characTerisTics
PARAMETER
Minimum Start-Up Voltage
No-Load Input Current
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are for T