MAX17710BEVKIT# Maxim Integrated, MAX17710BEVKIT# Datasheet - Page 10

• Manufacturer Part Number: MAX17710BEVKIT#
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Type: Energy Harvestingr
• Series: MAX17710r

Specifications of MAX17710BEVKIT#

• Product: Power Management Development Tools
• Tool Is For Evaluation Of: MAX17710
• Output Voltage: 1.8 V, 2.3 V, 3.3 V
• Output Current: 625 nA
• Part # Aliases: 90-NC01K#B00

The device includes a simple boost regulator controller to
support energy harvesting from low-voltage solar or ther-
moelectric generator (TEG) devices. The boost converter
can harvest energy down to approximately 1FW when
operated in pulsed harvest mode and as high as 100mW
in continuous conversion. For a 0.8V harvest source and
a 4.1V cell, the device can deliver over 20mA (80mW), as
long as the harvest source can support it.
the typical application boost circuit boost harvesting
from a low-voltage solar-cell array.
In the application circuit example, the solar cell array
charges the 47FF harvest-source capacitor until the volt-
age on FB exceeds the FB
LX pin is pulled low to force current through the external
inductor. LX begins to oscillate at a fixed 1.0MHz with
90% duty cycle. Each time LX is released by the device,
the external inductor forces the voltage of LX above CHG
and charges the 0.1FF CHG pin capacitor. When CHG
rises above the voltage of V
the cell. If the CHG pin exceeds 4.5V during this time,
the boost converter enters a skip-mode operation to
limit voltage on CHG to 4.5V. Operation continues until
the voltage of the harvest-source capacitor collapses,
Figure 2. Typical Application Boost Circuit Boost Harvesting from a Low-Voltage Solar-Cell Array
Maxim Integrated
SOLAR CELL 2
SOLAR CELL 1
Boost Regulator Operation
Energy-Harvesting Charger and Protector
ON
BATT
47µF
threshold. At this time, the
, charge is delivered to
300kI
0.1µF
THINERGY
MEC101
Figure 2
HIGH-SPEED
ZLLS410TA
SCHOTTKY
1.5µH
shows
BATT
SEL2
SEL1
CHG
LX
FB
GND
driving FB below the FB
the boost circuit. The process repeats after the harvest
source capacitor is recharged.
Because the boost converter draws its quiescent current
directly from the cell (for startup reasons), it is important
to only enable the boost converter when it can provide
more power than the boost converter consumes from the
cell. This can be guaranteed as long as the capacitor
across the TEG is large enough to boost CHG above the
BATT pin. Note that it is important to use a high-speed
Schottky diode between LX and CHG to guarantee LX
does not exceed its absolute maximum voltage rating
during boost operation.
External component selection depends on the charge
sources available to the device. Proper component
selection provides the highest efficiency operation of the
IC during energy harvesting. See
This section describes component selection for boost
sources with operational voltages of 1.0V or high-voltage
sources. For boost charge sources with operational volt-
ages between 1.0V and 2.0V, additional components
are required. See the
description.
EP
MAX17710
Charge Regulator Component Selection
PGND
PCKP
REG
LCE
10µF
AE
FB Divider
1µF
OFF
MICROCONTROLLER
LOAD V
MECHANICAL,
DETECTOR
RF, PIEZO,
OR OTHER
LOAD V
EVENT
threshold, which disables
DD
MAX17710
Figure 2
DD
section for a detailed
as a reference.
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