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Applications of Electrochemical Supercapacitors
retain data during a long-term power outage. Although data centers worldwide still rely on batteries to protect critical data on their servers and storage
controllers, long cycle lives and safety are still highly desired characteristics.
ESs are used throughout electronic circuit boards to regulate voltages that
can vary due to component power usage, distances, and conductance across
the devices. They work by storing a varying incoming electronic current
while sending out a constant level. The larger the ES, the more power it can
store. Like a battery, an ES can supply a circuit with enough energy to operate for a limited time. Actually, ESs have been used in this application for
decades, for example, supplying enough power to keep a mobile computer
alive while batteries are swapped.
Redundant arrays of independent disks (RAID) systems, are designed to
preserve data under adverse circumstances. One example is a power failure
that threatens data that is temporarily stored in volatile memory. To protect
this data, many systems incorporate a battery-based power back-up that supplies short-term power—enough watt-seconds for the RAID controller to
write volatile data to nonvolatile memory. With advances in flash memory
performance such as dynamic random access memory (DRAM), density, lower
power consumption, and faster write time, ESs with lower ESRs and higher
capacitances per unit volume made it possible to replace the batteries in these
systems with longer lasting and higher performance in a “greener” manner.
Servers and storage controllers use DRAM for many applications, but buffering or caching the output data is one of the most critical steps. If a system
loses power, the cache is gone unless the DRAM has some kind of nonvolatile feature. If the cache is targeted for a rotating drive or RAID striped
across multiple drives, data will be corrupted in the system and cannot be
recovered. The nonvolatility of the DRAM is provided by various types of
battery systems. The more recent applications involve the venerable lithium
ion (Li-ion) battery and associated charge circuit.
However, by using an ES to provide power during operation, increased
levels of protection (Figure 8.1) can also be achieved using an input voltage monitoring circuit to detect power failure and immediately write the
contents of the DRAM to an onboard flash memory array [2]. For example,
Viking Modular Solutions’ ArxCis-NV™ [3] using an ES was designed and
developed to back-up critical mission data in the event of a power failure.
This data, which formerly resided in volatile DRAM historically relied on
sub-optimal and unreliable batteries for protection. ArxCis-NV now offers a
highly reliable, secure, maintenance-free, and disaster-free solution for critical RAID applications.
ArxCis-NV is also environmentally conscious. It is a safe and green product
that requires no toxic battery disposal. Figure 8.2 shows a DDR3 ArxCis-NV
module that combines supercapacitor DRAM and flash memory to deliver
a persistent memory solution that saves critical data from power failures.
The circuit in Figure 8.1 shows a supercapacitor-based power backup system
using the LTC3625 charger. The system is also fitted with an automatic power
Applications of Electrochemical Supercapacitors
retain data during a long-term power outage. Although data centers worldwide still rely on batteries to protect critical data on their servers and storage
controllers, long cycle lives and safety are still highly desired characteristics.
ESs are used throughout electronic circuit boards to regulate voltages that
can vary due to component power usage, distances, and conductance across
the devices. They work by storing a varying incoming electronic current
while sending out a constant level. The larger the ES, the more power it can
store. Like a battery, an ES can supply a circuit with enough energy to operate for a limited time. Actually, ESs have been used in this application for
decades, for example, supplying enough power to keep a mobile computer
alive while batteries are swapped.
Redundant arrays of independent disks (RAID) systems, are designed to
preserve data under adverse circumstances. One example is a power failure
that threatens data that is temporarily stored in volatile memory. To protect
this data, many systems incorporate a battery-based power back-up that supplies short-term power—enough watt-seconds for the RAID controller to
write volatile data to nonvolatile memory. With advances in flash memory
performance such as dynamic random access memory (DRAM), density, lower
power consumption, and faster write time, ESs with lower ESRs and higher
capacitances per unit volume made it possible to replace the batteries in these
systems with longer lasting and higher performance in a “greener” manner.
Servers and storage controllers use DRAM for many applications, but buffering or caching the output data is one of the most critical steps. If a system
loses power, the cache is gone unless the DRAM has some kind of nonvolatile feature. If the cache is targeted for a rotating drive or RAID striped
across multiple drives, data will be corrupted in the system and cannot be
recovered. The nonvolatility of the DRAM is provided by various types of
battery systems. The more recent applications involve the venerable lithium
ion (Li-ion) battery and associated charge circuit.
However, by using an ES to provide power during operation, increased
levels of protection (Figure 8.1) can also be achieved using an input voltage monitoring circuit to detect power failure and immediately write the
contents of the DRAM to an onboard flash memory array [2]. For example,
Viking Modular Solutions’ ArxCis-NV™ [3] using an ES was designed and
developed to back-up critical mission data in the event of a power failure.
This data, which formerly resided in volatile DRAM historically relied on
sub-optimal and unreliable batteries for protection. ArxCis-NV now offers a
highly reliable, secure, maintenance-free, and disaster-free solution for critical RAID applications.
ArxCis-NV is also environmentally conscious. It is a safe and green product
that requires no toxic battery disposal. Figure 8.2 shows a DDR3 ArxCis-NV
module that combines supercapacitor DRAM and flash memory to deliver
a persistent memory solution that saves critical data from power failures.
The circuit in Figure 8.1 shows a supercapacitor-based power backup system
using the LTC3625 charger. The system is also fitted with an automatic power