CBC-EVAL-09 EnerChip EP Universal EH Eval Kit
Q:
How can the EVAL-09 startup time be reduced and the time it takes the CBC915 to find the maximum
peak power point?
The EVAL-09 utilizes a Seiko S-882Z24-M5T1G charge pump to accumulate energy at startup and then
dumps this energy into the CBC915 energy processor. Once the CBC915 starts up, it automatically
disables the Seiko charge pump and operates a more efficient inductive boost converter. Another
approach to start the CBC915 when energy is available, is to pre-charge the on-board EnerChips
and then use the base of an NPN bipolar transistor to sense when input voltage is available and tie
the collector of the transistor into the cutoff circuit as a wired OR. When energy is available from the
energy harvesting transducer, the transistor will turn on and cause energy stored in the EnerChips to
initially power the CBC915 energy processor. This approach has the advantage of being “instant on”,
but requires a board-level manufacturing process that can pre-charge the EnerChips and requires a
transducer to have a minimum of one forward PN junction voltage before the transistor will turn on.
The charge pump method operates at a lower voltage but in the case of piezo electric transducers has
a large impedance mismatch between the piezo element and the input into the charge pump so it can
take a long time (several minutes) before enough charge is accumulated to dump into the CBC915
energy processor.
A:
The length of time the CBC915 takes to find the maximum peak power point is largely influenced by
the stability of the input signal generated by the energy harvesting transducer. Mechanical transducers
tend to have the most electrical input noise and consequently take the most time for the CBC915
to find the maximum peak power point. Take steps to reduces noise such as filter capacitors in the
several thousand microfarad range. After the first time the CBC915 finds the maximum peak power
point, the coefficients used to find the point are stored in memory. The next time the CBC915 is
powered up it will use the coefficients and not try to find the maximum peak power point again unless
the system falls out of voltage regulation or is commanded to find the maximum peak power point by
the application circuit microcontroller.
Ordering Information
EnerChip Part Number
Description
Notes
CBC-EVAL-09
EnerChip Universal Energy
Harvesting Demo Kit
Contains Solar Cell and
CBC51100 Module
CBC915-ACA or
CBC915-ACB
EnerChip EP Energy Processor
Packaged in Tape and Reel or
Tubes
CBC050-M8C
CBC3150-D9C
CBC-PV-02N
EnerChip 50uAh Solid State
Packaged in Tape and Reel or
Tubes
Battery
EnerChip CC 50uAh Solid State
Battery with Charge Control
Packaged in Tape and Reel or
Tubes
EVAL-09 Photovoltaic Cell with two
lead wires - no connector
PV cell can be purchased
separately at Distributors
U.S. Patents 7,956,572 and 8,144,508. Additional U.S. and Foreign Patents Pending
Disclaimer of Warranties; As Is
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kind, express or implied, relating to this data sheet and the Cymbet battery product described herein, including without limitation, the
implied warranties of merchantability, fitness for a particular purpose, non-infringement, title, or any warranties arising out of course of
dealing, course of performance, or usage of trade. Cymbet battery products are not authorized for use in life critical applications. Users
shall confirm suitability of the Cymbet battery product in any products or applications in which the Cymbet battery product is adopted for
use and are solely responsible for all legal, regulatory, and safety-related requirements concerning their products and applications and any
use of the Cymbet battery product described herein in any such product or applications.
Cymbet, the Cymbet Logo and EnerChip are trademarks of Cymbet Corporation. All Rights Reserved
©2013 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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