Littelfuse.com
5
Fuses and Holders
Fuses – Full range including surface mount, axial,
glass or ceramic, thin-film or Nano
2®
style, fast-
acting or Slo-Blo
®
fuse.
Clips – Used in applications that require a fuse
to be easily mounted to a Printed Circuit Board
(PCB), but real estate is scarce. Clips are also ideal
for high-current applications, allowing for better
heat management of the fuse. They are the most
economical solution.
Blocks – An alternative solution to clips but
with easier placement on the PC board during
manufacturing. In some instances, blocks may
provide insulation to the side ears of the clips. In
addition to being through-hole, blocks can also be
screwed or riveted in place.
Holders – The ideal solutions for those applications
that require the cartridge fuse to be protected,
providing a shock-safe environment. Panel-mount
holders allow for easy replacement of the fuse from
outside of the appliance, perfect for applications
that require replacing the fuse without opening the
appliance enclosure.
PolySwitch
®
PPTC Devices
PolySwitch Polymeric Positive Temperature
Coefficient (PPTC) devices help protect against
damage caused by harmful overcurrent surges and
overtemperature faults. Like traditional fuses, these
devices limit the flow of dangerously high current
during fault conditions. The PolySwitch PPTC device,
however, resets after the fault is cleared and power
to the circuit is removed, thereby helping to reduce
warranty, service and repair costs. PolySwitch PPTC
devices are typically used in consumer electronics,
automotive, industrial, home appliance, HVAC, and
telecommunications applications.
TVS Diodes
The Transient Voltage Suppressor diode (TVS
Diode) is a protection diode designed to protect
electronic circuits from very fast and often
damaging voltage transients, such as lightning
and Electrostatic Discharge (ESD). TVS Diodes are
silicon avalanche devices typically chosen for their
fast response time (low clamping voltage), lower
capacitance, and low leakage current. TVS Diodes
are ideal for applications in computer, industrial,
telecom, and automotive markets.
TVS Diode Arrays
TVS Diode Arrays are designed to protect
electronics against transients and overvoltage
threats, such as Electrically Fast Transients (EFT)
and Electrostatic Discharge (ESD). Because of their
lower capacitance and low leakage current, they
offer an ideal protection solution for I/O interfaces
and digital and analog signal lines, in computer and
consumer portable electronics markets.
PulseGuard
®
ESD
Suppressors
PulseGuard suppressors use polymer composite
materials to suppress fast-rising ESD transients
while adding virtually no capacitance to the circuit.
PulseGuard suppressors are best suited for low-
voltage, high-speed applications such as protection
for high-speed protocols like USB 2.0, IEEE1394,
HDMI, and Digital Visual Interface (DVI), where low
capacitance is important.
Varistors
Varistors are available in multiple forms, from Metal
Oxide Varistors (MOVs) and Thermally Protected
MOV (TMOV
®
varistors) that suppress lightning
transient voltages to Multi-Layer Varistors (MLVs)
designed for applications requiring protection from
various ESD and EFT transients. They are often
used in computers and handheld devices as well
as in industrial and automotive applications.
Gas Discharge Tubes
Gas Discharge Tubes (GDTs) dissipate voltage
transients through a contained plasma gas.
They have high insulation resistance plus low
capacitance and leakage to ensure minimal
effect on normal operation of equipment. GDT’s
fast response to transient over-voltage events,
and ability to dissipate large amounts of energy,
translate into reduced risk of equipment damage.
The amount of energy dispersed by GDTs makes
them a good choice for lightning surge protection,
particularly for telecom equipment located in
outdoor structures.
PLED Bypass Protectors
PLED Bypass Protectors are specialty silicon
devices that enable LED lighting strings to
continue to function if any single LED fails as an
open circuit, and they also offer ESD and reverse
power protection. PLED are often incorporated
into the circuit designs of high-power LEDs in
applications such as roadway lights and outdoor
LED advertising display signs.
SIDACtor
®
Protection Thyristors
SIDACtor components use a patented ion implant
technology that ensures effective protection
within nanoseconds, up to 5000 A surge current
ratings. SIDACtors are designed to suppress
overvoltage transient surge in the telecom/
datacom applications, and they are also used to
protect industrial AC/DC powering terminals.
