AN-1008
Application Note
Using Cymbet™ EnerChip™ Batteries Instead of Coin Cells and
Super Capacitors
Introduction
Benefits of Using Cymbet Enerchips™
Primary and secondary (i.e., rechargeable) coin cell batteries,
Instead of Coin Cells and Super
as well as super capacitors, have been in use for years as
Capacitors
auxiliary power sources for applications including SRAM,
real-time clocks, and microcontrollers. Now, a new type of
rechargeable battery is available from Cymbet Corporation,
the leader in thin film rechargeable micro-batteries.
Cymbet™ EnerChip™ thin film, solid state batteries feature all
solid state construction, are packaged in standard integrated
circuit packages, and can be reflow soldered for high volume
PCB assembly. They are ideal as rechargeable backup power
sources for clocks, memories, microcontrollers and other low-
power circuits where data or timing information must be
retained in the absence of primary power. These new energy
storage devices present significant advantages over conventional
coin-type batteries and super capacitors in applications requiring
backup power.
The high charge/discharge cycle capability makes these
rechargeable batteries ideal as backup power sources for
low power circuits in cellular phones, pagers, point-of-sale
terminals, office equipment, home appliances, and other
devices where protecting data or timing information is either
essential to the enterprise, or simply gives convenience to
the consumer.
Another key advantage to using EnerChips is realized in
total energy savings, particularly in battery operated
equipment. For example, consider the case where a super
capacitor is used to provide backup power for a device
operated by a primary coin cell. This could be a home
thermostat, a remote sensor, a portable RFID reader,
portable medical instruments, or any other device operating
from a user-replaceable battery. The coin cell or prismatic
battery is used to power the system under normal operating
conditions, while the super capacitor provides a short-term
supply of energy to maintain memory or real-time clock
operation while the main battery is being replaced or
recharged. Because of the high self-discharge of many
types of super capacitors, and because the capacitor must
always be fully or nearly charged so that it will have a ready
supply of charge when needed unexpectedly, the main
battery must be continuously or regularly charging the
capacitor. As shown in Table 1, this results in a significant
current drain on the battery, diminishing its service life. A
Cymbet EnerChip is a preferred solution, as the self-
discharge of these batteries is substantially lower than that
of the super capacitor. This results in negligible wasted
energy and thus increases the useful life or time between
recharge cycles of the main battery. Moreover, the
EnerChip provides the backup energy equivalent to or
greater than the super capacitor while occupying less
volume – an advantage in space-constrained devices.
Features:
•
•
•
•
•
•
Solid state reliability
Low profile surface mount packaging
Simple charge control
Very high charge/discharge cycle life
High temperature solder reflow tolerant
Component class
Benefits:
•
•
•
•
Reduced size
Fewer parts
Lower overall cost
Higher reliability
Applications:
•
•
•
•
•
•
•
•
•
Utility meters
Digital video recorders
Set-top decoders
PABX hubs
RAID controllers
Point-of-sale terminals
Clock radios
Microwave ovens
Cellular phones
© Cymbet Corporation
•
18326 Joplin Street, Elk River, MN 55330
•
763-633-1780
•
www.cymbet.com
DOC-111008 RevA
Page
1
CYMBET [ CYMBET CORPORATION ]
