The DC2042A is a versatile energy harvesting demo board
that is capable of accepting piezoelectric, solar, 4mA to
20mA loops, thermal-powered energy sources or any high
impedance AC or DC source. The board contains four
independent circuits consisting of the following EH ICs:
®
• LT C
• LTC3108: Ultralow Voltage Step-Up Converter and
• LTC3105: Step-Up DC/DC Converter with Power Point
• LTC3459: 10V Micropower Synchronous Boost
• LTC2935-2/LTC2935-4: Ultralow Power Supervisor
The board supports the following interconnects:
• Direct connection with the Dust Mote demo boards, the
3588-1: Piezoelectric Energy Harvesting Power
Supply.
Power Manager.
Control and LDO Regulator.
Converter.
with Power-Fail Output Selectable Thresholds.
DC9003A-B Mote on a
on a chip.
chip or the DC9003A-A Manager
In addition, many turrets are provided and one transducer
header is available to make it easy to connect transducers
to the board.
The board contains multiple jumpers that allow the board
to be configured in various ways. The standard build for
the board has three jumpers installed out of the possible
10 jumpers. The board is very customizable to the end
users’ needs. This compatibility makes
ation tool for any low power energy harvesting system
Please refer to the individual data sheets for the operation of each power management circuit. The application
section of this demo manual describes the system level
functionality of this board and the various ways it can be
used in early design prototyping.
Design files for this circuit board are available at
http://www.
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.
linear.com/demo
it a perfect evalu-
• Energy Micro STK development kit.
DC2042A Connected to DC9003A-B Dust Mote (Top View)
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DEMO MANUAL DC2042A
DESCRIPTION
DC2042A Connected to DC9003A-B Dust Mote (Bottom View)
QUICK START PROCEDURE
Refer to Figures 2 through 6 for the proper measurement
equipment setup and jumper settings for the following
test procedure.
1. Note the Header KEY locations that guarantee proper
interconnect of compatible adaptor boards.
J1 (Energy Micro STK Header) does not have a KEY.
J2 (Dust Mote Header) has a KEY in position 5.
J3 (Horizontal Transducer Header, NOT INSTALLED
on standard build) has a KEY in position 12.
J1
J4 (Vertical Transducer Header) has a KEY in position
12.
J3
Figure 1b. J3, Horizontal Transducer Header
Figure 1a. J1, Energy Micro Header and J2, Dust Mote Header
2
J2
J4
Figure 1c. J4, Vertical Transducer Header
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QUICK START PROCEDURE
DEMO MANUAL DC2042A
2. Configure the test equipment and jumpers as shown
in Figure 2. Verify the jumper settings are as follows:
JP1. OPEN
JP2. OPEN
JP3. OPEN
JP4. OPEN
JP5. OPEN
JP6. OPEN
JP7. OPEN
JP8.INSTALLED
JP9.INSTALLED in “ON” Position
JP10. OPEN
3. Slowly increase PS1 and observe the voltage at which
VM2 turns on. VM1 should be equal to approximately
3.15V.
4. Slowly decrease PS1 towards zero. Observe the voltage on VM1 at which VM2 drops rapidly to 0V. VM1
should be equal to approximately 2.25V.
5. Turn off PS1
13. Turn off PS3
14. MOVE JP1 to JP3. Disconnect PS3 from the board and
set PS4 equal to 5.0V. Reconfigure the test equipment
as shown in Figure 5.
15. Turn on PS4. Observe the voltage on VM1 and VM2.
The voltage on VM1 should be approximately 0.34V
and on VM2 should be 3.3V.
16. Use VM3 to observe the voltage on JP7-2. The voltage
should be approximately equal to the level observed
on VM2.
17. Turn off PS4
18. MOVE JP3 to JP2. Disconnect PS4 from the board
and set PS5 equal to 0.32V. Reconfigure the test
equipment as shown in Figure 6.
19. Turn on PS5. Observe the voltage on VM1 and VM2.
The voltage on VM1 should be approximately 0.14V
and VM2 should be 3.3V.
20. Use VM3 to observe the voltage on JP6-2. The voltage
should be approximately 2.0V.
21. Use VM3 to observe the voltage on JP10-1. The voltage should be approximately 5.0V.
6. Install JP4 and reconfigure the test equipment as
shown in Figure 3 (Solar Circuit testing).
7. Disconnect PS2 and Set PS2 to 3.0V. Turn off PS2.
Reconnect PS2 and turn on PS2.
8. Observe the voltage on VM1 and VM2. The voltage
on VM1 should be approximately 2.49V and on VM2
should be 3.3V.
9. Turn off PS2
10. MOVE JP4 to JP1. Disconnect PS2 from the board.
Set PS3 equal to 6.0V. Reconfigure the test equipment
as shown in Figure 4.
11. Turn on PS3. Observe the voltage on VM1 and VM2.
The voltage on VM1 should be approximately 5.77V
and on VM2 should be 3.3V.
12. Use VM3 to observe the voltage on JP5-2. The voltage
should be equal to the same level observed on VM2.
22. Turn off PS5.
23. Reset the Jumpers as shown on Figure 7a.
JP1. OPEN
JP2. OPEN
JP3. OPEN
JP4.INSTALLED
JP5. OPEN
JP6. OPEN
JP7. OPEN
JP8.INSTALLED
JP9. INSTALLED in “ON” Position
JP10. OPEN
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DEMO MANUAL DC2042A
QUICK START PROCEDURE
Figure 2. VMCU Power Switchover Test Setup (Test Steps 2 to 5)
Figure 3. Solar Circuitry Test Setup (Test Steps 6 to 9 ) Proper Measurement Equipment Setup for DC2042A Solar Circuit Testing
4
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QUICK START PROCEDURE
Figure 4. Piezoelectric Circuitry Test Setup (Test Steps 10 to 13 )
Proper Measurement Equipment Setup for DC2042A Piezoelectric Circuit Testing
DEMO MANUAL DC2042A
Figure 5. 4mA to 20mA Loop Circuitry Test Setup (Test Steps 14 to 17)
Proper Measurement Equipment Setup for DC2042A 4mA to 20mA Loop Circuit Testing
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DEMO MANUAL DC2042A
QUICK START PROCEDURE
Figure 6. TEG-Powered Circuitry Test Setup (Test Steps 18 to 22)
Proper Measurement Equipment Setup for DC2042A TEG Circuit Testing
6
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QUICK START PROCEDURE
DEMO MANUAL DC2042A
J3 HORIZONTAL
TRANSDUCER
HEADER
Figure 7a. DC2042A Top Assembly Drawing
J4 VERTICAL
TRANSDUCER HEADER
J2 DUST
EH HEADER
Figure 7b. DC2042A Bottom Assembly Drawings
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DEMO MANUAL DC2042A
APPLICATION INFORMATION
JUMPER FUNCTIONS
JP1: Power selection jumper used to select the LTC3588-1,
piezoelectric energy harvesting power supply.
JP2: Power selection jumper used to select the LTC3108,
TEG-powered energy harvester.
JP3: Power selection jumper used to select the LTC3105,
powered by a diode voltage drop in a 4mA to 20mA loop.
JP4: Power selection jumper used to select the LTC3459
powered by a solar panel
JP5: Routes the LTC3588-1 PGOOD signal to the Dust
Header PGOOD output. The LTC3588-1 PGOOD comparator
produces a logic high referenced to VOUT on the PGOOD
pin the first time the converter reaches the sleep threshold
of the programmed VOUT, signaling that the output is in
regulation. The PGOOD pin will remain high until VOUT
falls to 92% of the desired regulation
ally, if PGOOD is high and VIN falls below the UVLO falling
threshold, PGOOD will remain high until VOUT falls to 92%
of the desired regulation point. This allows output energy
to be used even if the input is lost.
JP6: Routes the LTC3108 PGOOD signal to the Dust
Header PGOOD output.
JP7: Routes the LTC3105 PGOOD signal to the Dust
Header PGOOD output
JP8: Routes the LTC3459 PGOOD signal to the Dust
Header PGOOD output.
JP9: Connects the fifteen optional energy storage capacitors directly to VOUT (VSUPPLY of the Dust Header) to be
used by the load to store energy at the output voltage level.
The 100μF capacitors have a voltage coefficient of 0.61
of their labeled value at 3.3V and 0.47 at 5.25V. Caution:
Only JP9 or JP10
Do not populate both JP9 AND JP10.
JP10: Connects the fifteen optional energy storage ca-
pacitors directly to VSTORE of the LTC3108 TEG-powered
energy harvester circuit, which is the output for the Storage capacitor or battery. A large capacitor may be connected from VSTORE to GND for powering the system in
the event the input voltage
to the maximum VAUX clamp voltage, typically 5.25V.
.
may be connected at any one time.
is lost. It will be charged up
voltage. Addition-
The 100µF capacitors have a voltage coefficient of 0.47
at 5.25V. Caution: Only JP9 or JP10 may be connected
at any one time. Do not populate both JP9 and JP10.
Note: For this board to properly interface with a Dust
Mote (DC9003A-B) or a Manager (DC9003A-A) board and
switch
ing source, resistor R3 on the Dust Mote board must be
changed to 750kΩ and R4 must be changed to 5.1MΩ.
,
TURRET FUNCTIONS
PZ1 (E1): Input connection for piezoelectric element or
other AC source (used in conjunction with PZ2). A high
impedance DC source may be applied between this pin
and BGND to power the LTC3588-1 circuit. Caution
maximum current into this pin is 50mA.
PZ2 (E2): Input connection for piezoelectric element or
other AC source (used in conjunction with PZ1). A high
impedance DC source may be applied between this pin
and BGND to power the LTC3588-1 circuit. Caution:The
maximum current into this pin is 50mA.
VIN, 20mV to 400mV (E3): Input to the LTC3108, TEG-
powered energy harvester
LTC3108 power circuit is approximately 3Ω, so the source
impedance of the TEG should be less than 10Ω to have
good power transfer. TEGs with approximately 3Ω will
have the best power transfer. The input voltage range is
20mV to 400mV.
BGND (E4, E6, E8, E11, E14): This is the board ground.
BGND is connected to all the circuits on the board except
the headers. BGND and HGND, the header ground, are
connected through Q3 when the VMCU voltage with
respect to BGND reaches the rising RESET threshold of
U2 and disconnected when VMCU falls to the falling reset
threshold. The board is configured from the factory to
connect BGND and HGND when VMCU equals 3.15V and
disconnect them when VMCU equals 2.25V.
+VIN, 4mA to 20mA Loop (E5):
supplied by a diode voltage drop. The current into this
terminal must be limited to between 4mA and 20mA. The
current into this turret flows through diode D1 to generate the diode voltage drop and into the LTC3105 power
management circuit.
the power from the battery to the energy harvest-
. The input impedance of the
Input to the LTC3105
: The
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APPLICATION INFORMATION
DEMO MANUAL DC2042A
VIN SOLAR (E7): Input to the LTC3459, solar-powered
circuit with maximum power point control provided by
the LTC2935-4. The input regulation point for the MPPC
function is 1.73V. The input range is 1.72V to 3.3V.
HGND (E9, E13): This is the header ground. HGND is the
switched ground to the headers that ensures the load is
presented with a
are connected through Q3 when the VMCU voltage with
respect to BGND reaches the rising RESET threshold of
U2 and disconnected when VMCU falls to the falling reset
threshold. The board is configured from the factory to
connect BGND and HGND when VMCU equals 3.15V and
disconnect them when VMCU equals 2.25V.
VMCU (E10, E12): Regulated output of all the active
ergy harvester power management circuits, referenced to
BGND. When VMCU is referenced to HGND it is a switched
output that is passed through the headers, J1 and J2, to
power the load.
J2 DUST HEADER SIGNALS
Pin 1 (VSUPPLY): Switched power from EH multisource
demo board. As configured from the factory via the
LTC2935-2 circuitry, this voltage is switched on at 3.15V
and off at 2.25V.
Pin 2 (NC): No connect on EH multisource demo board.
Pin 3 (GND): Switched GND when VSUPPLY is greater
than 3.15V, rising and 2.25V, falling. On the board this
signal is labeled HGND.
Pin 4 (PGOOD): PGOOD signal from EH multisource
demo board. When this signal is high, the SPDT switch
on the DUST demo board will switch from the battery
the energy harvested source.
Pin 5 (KEY): Metal insert in header to ensure proper insertion location and orientation. No electrical connection.
Pin 6 (VBAT): Raw battery voltage from (to) DUST board.
Pin 7 (RSVD): Reserved for future use, no connection on
EH multisource board.
quickly rising voltage. BGND and HGND
en-
On the board this node is labeled VMCU.
to
Pin 8 (EHORBAT): Signal indicating if the battery or the
energy harvester is providing power to the system. Refer
to the individual device
of the polarity.
Pin 9 (I/O 2): Connected to general purpose I/O input on
DUST DC9003A-X.
Pin 10 (I/O 1): Connected to general purpose I/O input on
DUST DC9003A-X.
Pin 11 (+5V): 5V input provided by DC9006A board, not
anticipated to be used by or provided from EH board.
Pin 12 (V+): 12V input provided by DC
anticipated to be used by or provided from eh board.
J3 AND J4 TRANSDUCER HEADER SIGNALS
Pin 1 (VIN_LT C3459): Solar panel input. The allowable
range for this input voltage is 1.72V to 3.3V.
Pins 2, 4, 6, 8, 10 (GND): Connected to board ground
“BGND” to power the power management circuits.
Pin 3 (VIN_LT C3105): Connect in series with 4mA to 20mA
loop. The Loop current will flow
board GND connection.
Pin 5 (VIN_LT C3108): Thermal electric generator input,
input to step-up transformer. The allowable range for this
input voltage is 20mV to 400mV. The source impedance of
the TEG should be less than 10Ω for good power matching.
Pin 7 (VIN_LT C3588-1): Rectified AC voltage, direct input
to LTC3588-1 DC/DC. The allowable range for this input
voltage is
the maximum current allowed into this pin is 5mA.
Pin 9 (PZ1): Raw battery voltage from (to) the DC9003A-X
DUST board.
Pin 11 (PZ2): Reserved for future use, no connection on
EH multisource board.
Pin 12 (KEY): Metal insert in header to ensure proper
insertion location and orientation. No electrical connection.
5V to 18V. If the DC source is greater than 18V,
data sheet for the interpretation
9006A board, not
into this pin and out a
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DEMO MANUAL DC2042A
APPLICATION INFORMATION
LTC3588-1: PIEZOELECTRIC ENERGY HARVESTING
POWER SUPPLY (VIBRATION OR HIGH IMPEDANCE
AC SOURCE)
The LTC3588-1 piezoelectric energy harvesting power
supply is selected by installing the power selection jumper,
JP1. The PGOOD signal can be routed to the Dust Header
by installing jumper JP5. The Dust Eterna board will switch
from battery power to energy harvester power whenever
the PGOOD signal is high, provided
the Dust Mote board (DC9003A-B) is changed to 750kΩ
and R4 is changed to 5.1MΩ.
If the application requires a wide hyteresis window for
the PGOOD signal, the board has the provision to use the
independent PGOOD signal, shown in Figure 12, generated
by the LTC2935-2 and available on JP8. This signal is
labeled as the PGOOD signal for the LTC3459
(PGOOD_LTC3459), because the LTC3459 does not have
its own PGOOD output. The PGOOD_LTC3459 signal can
be used in place of any of the PGOOD signals generated
by the harvester circuits. The board is configured from
the factory to use the PGOOD_LT C 3459 signal as the
PGOOD signal to switch from battery power to energy
harvesting power.
The PGOOD_LT C 3459 signal is always used
the output voltage on the header. Some loads do not like
to see a slowly rising input voltage. Switch Q3 ensures
that VSUPPLY and VMCU on the headers are off until the
energy harvested output voltage is high enough to power
the load. The LTC2935-2 is configured to turn on Q3 at
3.15V and turn off Q3 at 2.25V. With this circuit, the load
will see a fast voltage rise at start-up and be able to utilize
all the energy stored in the output capacitors between the
3.15V and 2.25V levels.
that resistor R3 on
circuit
to switch
The optional components R1, R4, Q1 and C5 shown on
the schematic are not populated for a standard assembly.
The function of R1, R4, Q1 and C5 is to generate a short
PGOOD pulse that will indicate when
is charged to its maximum value. The short pulse occurs
every time the output capacitor charges up to the “output
sleep threshold,” which for a 3.3V output is 3.312V. By
populating these components the application can use
this short pulse as a sequence timer to step through the
program sequence or as an indication of when it can
perform energy-intensive functions, such as
read or a wireless transmission and/or receive, knowing
precisely how much charge is available in the output
capacitors. When this optional circuit is not used, the
amount of charge in the output capacitors is anywhere
between the maximum (C
cent low. In the case where the energy harvesting source
can support the average load continuously, this optional
circuit is not needed.
Diode D2 is an optional component used to “Diode-OR”
multiple energy harvesting sources together. This diode
would be used in conjunction with one or more of the
other Oring diodes, D3, D4 or D5. When the Oring diodes
installed the parallel jumper would not be populated.
are
The diode drop will be subtracted from the output voltage regulation point, so it is recommended to change
the feedback resistors or select a higher output voltage
setpoint to compensate for the diode drop. When more
than one of these diodes is installed and the associated
energy harvester inputs are powered, the board will switch
between energy harvester
maintain the output voltage.
•V
OUT
power circuits as needed to
the output capacitor
OUT_SLEEP
) to eight per-
a sensor
Figure 8. Detailed Schematic of LTC3588-1 Piezoelectric Energy Harvesting Power Supply
10
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APPLICATION INFORMATION
DEMO MANUAL DC2042A
LTC3108: TEG-POWERED ENERGY HARVESTER
The LTC3108 TEG-powered energy harvester is selected
by installing the power selection jumper JP2. The PGOOD
signal, PGOOD_LTC3108, can be routed to the Dust
Header by installing jumper JP6. The LTC3108 PGOOD
signal is pulled up to the on-chip 2.2V LDO through a
1MΩ pull-up resistor. The Dust Eterna board will switch
battery power to energy harvester power whenever
from
the PGOOD_LT C 3108 signal is high. Provided that, R4,
on the Dust Mote demo board, DC9003A-B, is changed
to 5.1MΩ.
If the application requires a wide hysteresis window for
the PGOOD signal, please refer to the above section for a
complete operational description of and how to use the
independent PGOOD signal (PGOOD_LT C 3459), shown
in Figure 12, generated
on JP8.
The PGOOD_LT C 3459 signal is always used to switch
the output voltage on the header. Some loads do not like
to see a slowly rising input voltage. Switch Q3 ensures
that VSUPPLY and VMCU on the headers are off until the
energy harvested output voltage is high enough to power
the load.
When the PGOOD signal from the LTC3108
the header signal, the setpoint for the LTC2935-2 circuit
by the LTC2935-2 and available
is used as
needs to be changed so the turn-on threshold is below
the PGOOD_LT C 3108 turn-on threshold of 3.053V. For
example, by changing R36 to a 0Ω jumper and R5 to
“NOPOP”, the turn-on threshold for Q3 will be 2.99V rising and 2.25V falling.
The single supply SPDT analog switch, ISL43L210, on
Dust Mote needs a digital input voltage greater than 1.4V
to consider it a “Logic 1” and switch from the battery to
the energy harvester-powered source. When using the
PGOOD signal from the LTC3108, the pull-down resistor,
R4, on the Dust Mote demo board, DC9003A-B, should
be changed to 5.1MΩ to avoid creating a resistor divider
with the internal 1MΩ LTC3108 PGOOD
Diode D3 is an optional component used to “Diode-OR”
multiple energy harvesting sources together. This diode
would be used in conjunction with one or more of the
other Oring diodes, D2, D4 or D5. When the Oring diodes
are installed the parallel jumper would not be populated.
The diode drop will be subtracted from the output voltage
setpoint, so it is recommended to
resistors or select a higher output voltage setpoint to
compensate for the diode drop. When more than one of
these diodes is installed and the associated energy harvester inputs are powered, the board will switch between
energy harvester power circuits as needed to maintain
the output voltage.
pull-up resistor.
change the feedback
the
Figure 9. Detailed Schematic of LTC3108 TEG-Powered Energy Harvester
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DEMO MANUAL DC2042A
APPLICATION INFORMATION
LTC3105: SUPPLIED BY DIODE VOLTAGE DROP IN
4mA TO 20mA LOOP
The LTC3105 4mA to 20mA loop, diode voltage droppowered energy harvester is selected by installing the
power selection jumper, JP3. The PGOOD signal, PGOOD_
LTC3105, can be routed to the Dust Header by installing
jumper JP7. The PGOOD_LTC3105 signal is an open-drain
output. The pull-down is
first sleep event after the output voltage has risen above
90% of its regulation value. PGOOD_LTC3105 remains
asserted until VOUT drops below 90% of its regulation
value at which point PGOOD_LT C 3105 will pull low. The
pull-down is also disabled while the IC is in shutdown or
start-up mode. The Dust Eterna board will switch from
battery power to energy
PGOOD signal is high (>1.4V). Again a resistor divider is
generated by the pull-up resistor R23 on the DC2042A
and R4, the pull-down resistor on the DC9003A-A or
DC9003A-B. Provided that R4 is changed as described
above to 5.1MΩ, the voltage seen by the analog switch
will be sufficient to register as a “Logic 1” and switch
Mote or Manager from the battery to the energy harvested
source.
If the application would benefit from a wider PGOOD
hyteresis window than the LTC3105 provides (sleep to
minus 10%), please refer to the above section for a
V
OUT
complete operational description of and how to use the
independent PGOOD signal (PGOOD_LT C 3459), shown
in Figure 12, generated by the LTC2935-2 and available
on JP8.
disabled at the beginning of the
harvester power whenever the
the
PGOOD_LT C3459 signal is always used to switch the
The
output voltage on the Header. Some loads do not like to
see a slowly rising input voltage. Switch Q3 ensures that
VSUPPLY and VMCU on the headers are off until the energy
harvested output voltage is high enough to power the load.
The PGOOD_LT C3459 signal can be used in place of any
of the PGOOD signals generated
The optional components shown on the schematic are not
populated for a standard assembly. The function of R22 and
Q2 is to generate a short PGOOD pulse that will indicate
when the output capacitor is charged to its maximum value.
The short pulse occurs every time the output capacitor
charges up to the “output sleep threshold”, which for a
3.3V output is 3.312
the application can use this short pulse as a sequence timer
to step through the program sequence or as an indication
of when it can perform energy intensive functions, such as
a sensor read or a wireless transmission and/or receive,
knowing precisely how much charge is available in the
output capacitors. When this optional circuit is not used,
the amount of
between the maximum (C
low. In the case where the energy harvesting source can
support the average load continuously, this optional circuit
is not needed.
V. By populating these components
charge in the output capacitors is anywhere
by the harvester circuits.
•V
OUT
OUT_SLEEP
) to ten percent
Figure 10. Detailed Schematic of LTC3105 4mA to 20mA Loop, Diode Voltage Drop Energy Harvester
12
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APPLICATION INFORMATION
DEMO MANUAL DC2042A
Diode D4 is an optional component used to “Diode-OR”
multiple energy harvesting sources together. This diode
would be used in conjunction with one or more of the other
Oring diodes, D2, D3 or D5. When the Oring diodes are
installed the parallel jumper would not be populated. The
diode drop will be subtracted from the output voltage setpoint so it
or select a higher output voltage setpoint to compensate
for the diode drop. When more than one of these diodes
is installed and the associated energy harvester inputs are
powered, the board will switch between energy harvester
power circuits as needed to maintain the output voltage.
LTC3459 SUPPLIED BY SOLAR CELL
The LTC3459 solar-powered energy harvester is selected
installing the power selection jumper, JP4. The PGOOD
by
signal, PGOOD_LT C 3459, can be routed to the Dust Header
by installing jumper JP8.
The LTC2935-4 adds a hysteretic input voltage regulation
function to the LTC3459 application circuit. The PFO output
of the LTC2935-4 is connected to the SHDN input on the
LTC3459, which means that the LTC3459 will be off until
VIN_LTC3459 rises above 1.743
will then turn off when VIN_LT C 3459 falls below 1.72V.
The result is that the input voltage to the LTC3459 circuit
will be regulated to 1.73V, the average of the LTC2934-4
rising and falling PFO thresholds. The threshold can be
adjusted for the peak operating point of the solar panel
selected. In this design, because the LTC3459 output is
set to 3.3V and
limited to 3.3V.
The LTC3459 does not have an internally generated
PGOOD signal so the LTC2935-2 was used to generate a
PGOOD function with an adjustable hysteresis window.
The NOPOP and 0Ω resistors around the LTC2935-2 allow
is recommended to change the feedback resistors
V (1.72V + 2.5%) and
is a boost topology, the input voltage is
for customization of the PGOOD thresholds and hysteresis
window. By using R14, R35 and R36 the inputs can be
changed after
large hysteresis window.
The PGOOD_LTC3459 signal can be used in place of any
of the PGOOD signals generated by the harvester circuits.
The PGOOD_LTC3459 signal is always used to switch the
output voltage on the header. The board is configured
from the factory to use the PGOOD_LT C 3459 signal as
the PGOOD signal to switch from battery power
harvesting power.
The PGOOD_LT C 3459 signal is always used to switch
the output voltage on the header. Some loads do not like
to see a slowly rising input voltage. Switch Q3 ensures
that VSUPPLY and VMCU on the headers are off until the
energy harvested output voltage is high enough to power
the load. The LTC2935-2 is configured to to turn on Q3 at
3.15V and turn off Q3 at 2.25V. With this circuit, the load
will see a fast voltage rise at start-up and be able to utilize
all the energy stored in the output capacitors between the
3.15V and 2.25V levels.
Diode D4 is an optional component used to “Diode-OR”
multiple energy harvesting sources together. This diode
would be used in conjunction with one or more
other Oring diodes, D2, D3 or D5. When the Oring diodes
are installed the parallel jumper would not be populated.
The diode drop will be subtracted from the output voltage
setpoint, so it is recommended to change the feedback
resistors or select a higher output voltage setpoint to
compensate for the diode drop. When more than one of
these diodes is installed and the associated
vester inputs are powered, the board will switch between
energy harvester power circuits as needed to maintain
the output voltage.
the rising threshold is reached, creating a
to energy
of the
energy har-
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DEMO MANUAL DC2042A
APPLICATION INFORMATION
Figure 11: Detailed Schematic of LTC3459 Supplied by a Solar Cell
Figure 12: Detailed Schematic of PGOOD_LT C 3459 Circuit Using LTC2935-2
14
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APPLICATION INFORMATION
DEMO MANUAL DC2042A
SAMPLE OPERATION OF THE LTC3459 CIRCUIT
WITH VARYING LIGHT LEVELS IN A WIRELESS MESH
NETWORK APPLICATION.
Figure 13 shows a demonstration system using the
DC2042A EH multisource demo board connected to a
DC9003A-B Dust Mote, all powered by a G24i, Indy4100
solar panel and a CR2032 primary cell lithium-ion battery. The G24i Indy4100 solar panel has
100mm long. The system will duty cycle the battery use
as needed when the light level is insufficient to power the
wireless sensor node continuously. The scope photos
show in Figures 14 through 17 how the supply voltage on
the DC9003A-B is switched between the energy harvested
power (3.312V – 2.25V) and the battery voltage (3.0V).
In this way the life of the
possible.
battery is extended as much as
four lanes and is
Legend for (Figures 14 to 17):
1) The ground for the probes is referenced to the GND on
the mote board.
2) Probe Signals:
a) GREEN = VMCU on the EH Board (J2-1 on DC2042A)
b) YELLOW = PGOOD_LTC 3459 (J2-4 on DC2042A)
c) BLUE = VBAT on Mote Board or (J2-6 on DC2042A)
d) PINK = VSUPPLY (P2 -1 on Mote Board)
Figure 13. Solar Powered DC2042A in a MESH Wireless Sensor Network
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DEMO MANUAL DC2042A
APPLICATION INFORMATION
Figure 14. DC2042A LTC3459 Operation at 100 lux with Indy4100
Solar Panel
Figure 15: DC2042A LTC3459 Operation at 210 lux with Indy4100
Solar Panel
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APPLICATION INFORMATION
DEMO MANUAL DC2042A
Figure 16. DC2042A LTC3459 Operation at 275 lux with Indy4100
Solar Panel
Figure 17. DC2042A LTC3459 Operation at 300 lux with Indy4100
Solar Panel
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DEMO MANUAL DC2042A
PARTS LIST
ITEMQTYREFERENCEPART DESCRIPTIONMANUFACTURER/PART NUMBER
94SCREWSCREW, MACH, PHIL, 4-40, 0.250 IN, NYLONB&F FASTENER SUPPLY, NY PMS
R14, R15, R18, R31, R32,
R33, R36
9, JP10HEADER, 3 PINS, 2mmSAMTEC, TMM-103-02-L-S
JP7, JP10
MANAGER, DFN 3mm x 4mm
250mV START-UP, DFN 3mm x 3mm
DFN 2mm X 2mm
WITH POWER-FAIL
OUTPUT, TSOT-23, 8-PIN
ppm/°CVISHAY, CRCW04024K99FKED
RES., CHIP, 0402NOPOP
SHUNT 2MM, (DO NOT INSTALL)SAMTEC, 2SN-BK-G
0.100"
SMT HORIZONTAL SOCKET w/KEY,
0.100"
LINEAR TECH., LTC3108EDE
LINEAR TECH., LTC3105EDD
LINEAR TECH., LTC3459EDC
LINEAR TECH., LTC2935CTS8-4
SAMTEC, SMH-106-02-L-D-05
SAMTEC, SMH-106-02-L-D-12
440 0025 PH
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DEMO MANUAL DC2042A
SCHEMATIC DIAGRAM
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SCHEMATIC DIAGRAM
DEMO MANUAL DC2042A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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DEMO MANUAL DC2042A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LT C for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LT C from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LT C application engineer.