Datasheet (PDF) - Mide Technology

PEHBLE
Piezo Energy Harvesting Battery-Life Extender - EHE005
FEATURES
DESCRIPTION
•• Complete Power Management Solution for Battery
Assisted Piezo Energy Harvesting
The Piezo-Energy Harvesting Battery Life Extender
(PEHBLE) EHE005 is a power management solution that
combines the reliability of a battery with the renewability
of energy harvesting. The on-board battery ensures
that power is delivered to the load when needed, and
intelligent power selection uses the energy harvested
from environmental vibrations whenever available. The
PEHBLE is built around Linear Technology’s LTC3330
nanopower Buck-Boost chip which will detect and
select harvested energy, and seamlessly switch to
battery energy when it’s needed to maintain power to
the load. The PEHBLE is ideal for applications such
as remote wireless sensing where vibration energy is
present, but not consistent enough to rely on full time.
•• Efficient Conversion & Regulation of Harvested Energy
•• Compatible with Volture™ Energy Harvesting Piezos
•• Two Separate, Selectable Output Voltages
- from 1.8V to 5V
•• Coin Cell Battery Holder With Energizer CR2430
- Battery Included
•• Adjustable UVLO Thresholds For Optimized
Voltage Conversion
APPLICATIONS
•• Industrial Health Monitoring Network Sensors
•• Condition Based Maintenance Sensors
•• Wireless HVAC Sensors
•• Mobile Asset Tracking
•• Tire Pressure Sensors
A low noise LDO post regulator and a supercapacitor
balancer are also integrated, accommodating a wide
range of output storage configurations. Voltage and
current settings for both inputs and outputs are
programmable via pin-strapped logic inputs.
•• Oil and Gas Sensors
•• All Air, Land, and Sea Vehicle Sensors Battery
and Hard Wired Power Replacement
ABSOLUTE MAXIMUM RATINGS
Peak Piezo Input Voltage
Piezo Input Current
Storage Temperature
Operating Temperature
Battery Voltage
Output Current at VOut
Output Current at LDO
19V (clamped at 20V)
25mA
-65C to 150C
-40C to 125C
-0.3 to 6V
350mA
50mA
The PEHBLE features selectable output voltage, a
secondary low-dropout regulator (LDO) output voltage,
and adjustable under voltage-lockout (UVLO) thresholds.
The performance of the PEHBLE can be tailored to
different applications by adjusting the UVLO thresholds,
and the low-noise LDO post regulator provides a clean
voltage source, eliminating the need for a second layer
of regulation of the user end.
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CHARACTERISTICS
Electrical Characteristics
From the LTC3330 datasheet:
Output Voltage:
1.8, 2.5, 2.8, 3.0, 3.3,
3.6, 4.5, 5.0V
Energy Harvesting Input 3V to 19V (Clamped
Voltage:
at 20V)
Battery Input Voltage:
1.8V to 5.5V
Maximum Output Current: 50mA
Quiescent Current:
750nA (unloaded)
Protective Shunt Current 25mA at Vin <= 20V
(input):
Input Capacitance:
10uF
Output Capacitance:
22mF
“The LTC®3330 integrates a high voltage energy
harvesting power supply plus a DC/DC converter
powered by a primary cell battery to create a single
output supply for alternative energy applications.
The energy harvesting power supply, consisting
of an integrated full-wave bridge rectifier and a
high voltage buck converter, harvests energy from
piezoelectric, solar, or magnetic sources. The
primary cell input powers a buck-boost converter
capable of operation down to 1.8V at its input.
Either DC/DC converter can deliver energy to a
single output. The buck operates when harvested
energy is available, reducing the quiescent current
draw on the battery to essentially zero, thereby
extending the life of the battery. The buck-boost
powers VOUT only when harvested energy goes
away.
”
For more information please visit:
http://cds.linear.com/docs/en/datasheet/3330fa.pdf
Principle of Operation
The PEHBLE is based on the LTC3330 chip, which uses
two switching converters, a buck and a buck-boost,
to feed a regulated voltage output. The buck converter
serves the energy harvesting input, and the buck-boost
converter serves the battery input. When no harvested
energy is present, the chip selects the battery input
to power the output voltage through the buck-boost.
When harvested energy is available, it builds up on
the input capacitor until the voltage passes the rising
UVLO threshold. Once the rising threshold is passed,
the prioritizer turns on the buck converter and shuts
off the buck-boost, sending the harvested energy to
the output and halting the energy flow from the battery.
The battery will be reselected when harvested energy
is no longer present.
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Configuration
The device has three monitor pins that can be used to
determine the power output status. These are EH_ON,
PGVOUT, and PGLDO, and are located on a 4 pin, 0.1”
pitch header on the edge of the board along with the
LDO voltage.
The EH_ON pin indicates whether the buck converter
is enabled and using harvested energy. A low value
of 0V indicates the buck converter is disabled and no
harvested energy is available. When harvested energy
is in use and the buck converter is active, VIN3 will be
a diode drop below the input voltage VIN, about 3V, up
to a regulated level of 4.8V.
The PGVOUT pin indicates the regulation status of
VOUT. A transition from low to high on this pin indicates
regulation has been achieved. A high to low transition
indicates that PGVOUT has dropped below 92% of the
nominally selected value.
5
4
6
3
2
1
7
Figure 3: The PEHBLE board with the following areas highlighted:
1: LDO enable jumper
2: LDO voltage selection jumpers
3: VOUT voltage selection jumpers
4: UVLO threshold selection jumpers
5: Screw terminal input for piezo device
6: Power status indicator pins
7: Screw terminal output for VOUT.
The PGLDO pin indicates the regulation status of LDO_
OUT, and functions similarly to PGVOUT. This pin will
transition from low to high when LDO_OUT reaches
92% of its nominally selected value. A high to low
transition occurs when LDO_OUT falls below 90% of
the nominally selected value.
The PEHBLE has four jumper selectable variables:
output voltage on VOUT, UVLO threshold voltage, output
voltage on LDO, and enable for LDO. The jumpers are
located on the opposite edge of the board from the IO,
as noted on. Figure 3 shows the board with selection
jumpers and power input/output highlighted.
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Selecting voltage on VOUT
Enabling and selecting the voltage on LDO
The main output voltage on VOUT is determined by three
jumpers J5, J6, and J7. These correspond to OUT2,
OUT1, and OUT0 on the LTC3330. These jumpers are
on the edge of the board, as shown in Figure 3. A “0”
is selected by placing the jumper over the left two pins,
closest to the edge of the board. A “1” is selected
by placing the jumper over the right two pins, away
from the edge of the board. The following table shows
the possible output voltages and their corresponding
jumper settings:
A secondary output voltage is available on the LDO
pin that can be enabled by placing the jumper at J4
to connect LDO_IN with LDO_EN. The jumpers J8,
J9, and J10 control the LDO[2:0] pins, which can be
adjusted to change the voltage level according to the
table shown below. The LDO regulator is powered
directly from VOUT, and can act as a current limited
switch that will match the input voltage of the regulator.
A “0” is selected by placing the jumper over the left
two pins, closest to the edge of the board. A “1” is
selected by placing the jumper over the right two pins,
away from the edge of the board. Not that in the “111”
configuration, LDO is matched to VOUT.
Output Voltage Selection (VOUT)
J5
0
0
0
0
1
1
1
1
J6
0
0
1
1
0
0
1
1
J7
0
1
0
1
0
1
0
1
VOUT
1.8V
2.5V
2.8V
3.0V
3.3V
3.6V
4.5V
5.0V
LDO Voltage Selection (LDO)
J8
0
0
0
0
1
1
1
1
REVISION No. 002 REVISION DATE: 02-21-2014
J9
0
0
1
1
0
0
1
1
J10
0
1
0
1
0
1
0
1
LDO_OUT
1.2V
1.5V
1.8V
2.0V
2.5V
3.0V
3.3V
VOUT
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Setting the UVLO thresholds
Connecting a Piezo Device
The UVLO threshold selection can be adjusted by
jumpers on J11, J12, J13, and J14 which correspond
to UV[3:0]. The table below shows the settings for
UVLO and the corresponding jumper positions. The
UVLO monitors VIN, where piezo voltage is stored on a
capacitor after being rectified. When VIN passes above
the rising threshold it will turn on the buck converter,
and turn off the buck-boost converter, to power VOUT
from harvested energy. When VIN passes below the
falling threshold, the buck converter will be disabled
and the battery buck-boost will be enabled if the battery
voltage is at least 1.8V.
The input for a piezo device is a two position screw
terminal labeled VIN that feeds directly into the full-wave
bridge rectifier. Midé offers a number of piezo devices in
either unimorph or bimorph packages. The unimorphs
have a single piezoceramic crystal with two contacts.
The bimorph packages contain two crystals, and have
four contacts. The unimorph packages are inherently
compatible with the PEHBLE, and Midé provides 4-to-2
contact adapters for the bimorph packages. For more
information on piezo packages, refer to the Volture
Energy Harvesting section of Midé’s website.
Power Output
J11 J12 J13 J14
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
UVLO
Rising
4V
5V
6V
7V
8V
8V
10V
10V
12V
12V
14V
14V
16V
16V
18V
18V
UVLO
Falling
3V
4V
5V
6V
7V
5V
9V
5V
11V
5V
13V
5V
15V
5V
17V
5V
For more information on VOUT, LDO, and UVLO, refer
to the LTC3330 datasheet.
Power output is guaranteed as long as the battery
retains a charge, but the life of the device depends on
how much harvested energy is available and usable.
The amount of power that can be captured by a piezo
depends on the amplitude and frequency of vibration.
Details on operation and tuning of energy harvesting
piezos are available on Midé’s website. For reference,
Figure 1 shows the relationship between the maximum
power output of the PEHBLE from harvested energy
and the power input, measured in peak acceleration
seen by the piezo.
Max Power Output Vs Acceleration (66.5 HZ)
PEHBLE Output Power (mW)
UVLO Rising/Falling Threshold Selection
2.5
2
1.5
1
0.5
0
0.2
0.4
0.6
0.8
1
1.2
Peak Acceleration(g)
Figure 1: Power data gathered from tests using Midé’s Volture V25W
piezo. A 7.5g tip mass was used to adjust the resonance frequency of
the piezo to match the 66.5Hz driving frequency.
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PCB parts side (Left)
+
-
BATT1
+
-
4.7uF,6.3V
C3
4.7uF,6.3V
C7
R6
R5
GND
10
10_VIN
11
11_CAP
3
3_VIN2
12
10
Load = 10KΩ
Load = 5KΩ
Load = 3.3KΩ
Load = 2.5KΩ
8
6
4
2
0.4
0.5
0.6
0.7
0.8
0.9
1
Acceleration (g)
Figure 2: Acceleration and peak voltage output from a piezo. The loads
were powered from Vout at 1.8V, with the UVLO rising threshold set to 5V.
VIN3
GND
LTC3330
16
1uF,6.3V
C9
26
26_VIN3
OUT0 30
OUT1 31
OUT2 32
30_OUT0
31_OUT1
32_OUT2
LDO2 22
LDO1 23
LDO0 24
22_LDO2
23_LDO1
24_LDO0
17
IPK0
18
IPK1
IPK2 19
UV0 7
UV1 6
UV2 5
UV3 4
1 LDO_IN
25
LDO_EN
R7
2
R4
R3
R2
1
GND
14
16_BAT
17_IPK0
18_IPK1
19_IPK2
7_UV0
6_UV1
5_UV2
4_UV3
25_LDO_EN
12_SW
12
15_SWA 15
14_SWB 14
13_VOUT
L3 22uH
L2 22uH
13
21_LDO_IN 21 LDO_IN
2_SCAP 2
1_BAL
C1
1
29_EH_ON 29 EH_ON
28_PGVOUT 28 PGVOUT
27_PGLDO 27 PGLDO
1
20_LDO_OUT 20 LDO_OUT
33_GND
0
R1
G
J4
VOUT
P$2
NP
P$1
R8
NP C4
NP
C2 R9
J1
V_OUT
100uF
C11
9_AC2
1uF,6.3V
C8
9
10uF,25V
C6
8_AC1
P$2
J2
SJ_3S
16
GND
NP C5
GND
22uF
C10
U3
8
GND
18
PCB IO side (Right)
PiezoVoltageInput
P$1
3
Piezo Voltage Vs Acceleration (Load)
20
Power Amplitude (V)
Another important consideration for harvested energy
is the peak piezo output voltage. If this voltage does
not exceed the UVLO rising threshold, harvested
energy cannot be used to power the PEHBLE. While
the vibrational characteristics determine the maximum
voltage output of the piezo, the actual peak voltage is
affected by the size of the electrical load. As the current
draw of the load rises, the peak piezo voltage drops.
The graph in Figure 2 shows the relationship of peak
voltage and acceleration at different load values.
Schematic (unedited)
GND
GND
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PEHBLE - EHE005
The Bill of Materials (BOM) for the PEHBLE.
Qty Parts (Ref. Des.)
Package
Value
Manufacturer, Part Number
1
BATT1
24.5mm Coin Cell
Holder
1
BATTERY
24.5mm x 3mm
3V, 290mAh
Energizer, CR2430VP
2
C1, C2
1206
11mF, 3.3V
Taiyo Yuden, PAS3225P3R3113
1
C11
1206
100uF
Kemet, C1206C107M9PACTU
2
C3, C7
0603
4.7uF, 6.3V
Taiyo Yuden, JMK107BJ475KA-T
1
C6
C-EUC0805
10uF, 25V
Samsung, CL21A475KBQNNNE
2
C8, C9
C-EUC0603K
1uF, 6.3V
Taiyo Yuden, LMK107B7105KA-T
11
J4, J5, J6, J7, J8, J9,
J10, J11, J12, J13, J14
3 pin, 0.50” pitch
male header
2
L2, L3
3816
2
P_OUT, V_IN
2 position, 0.10”
pitch screw terminal
1
R1
R-US_R0402
0
Yageo, RC0402JR-070RL
3
R2, R4, R6
R-US_R0603
10K
Yageo, RC0402JR-0710KL
1
U3
LTC3330
LTC3330
Linear Technology,
LTC3330EUH#PBF
Memory Protection Devices,
BH2430T-C
Sullins Connector Solutions,
GRPB031VWVN-RC
22uH
Wurth Electronics, 744031220
TE Connectivity, 282834-2
MORE INFORMATION
For questions or ordering information. Please contact
Midé at;
Email: [email protected]
Phone: +1 781-306-0609
Web: www.mide.com
REVISION No. 002 REVISION DATE: 02-21-2014
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