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Silicon Avalanche Diodes
Axial Leaded Telecommunications Transient Voltage Suppressors
FOLDBAK
TM
SERIES
Designed to protect sensitive telecommunications electronics from
transients which originate from induced lightning, power cross
and inductive load switching etc., especially where breakover
devices would cause nuisance latch-up.
Typical equipment would be: line cards, PABX, modems,
multiplexers and NTDs.
FEATURES
Foldback characteristics
2200 watts Peak Power rated with 10/1000S pulse
30,000 watts Peak Pulse Power based on 8/20S
UL 94V-0 flammability classification
DESCRIPTION
The foldback characteristic of this device eliminates the clamping
of the DC current, or the battery, used in telecom systems, so
latch-up is eliminated. Latch-up can occur with breakover devices
due to the conduction follow-on current supplied by the DC
system, after the device has responded to a transient.
With breakover devices, latch-up will happen more readily as the
ambient temperature rises because the holding current values will
fall with rising temperature.
The Foldbak eliminates this problem while still providing high
levels of protection.
Min 25.4
4.826
5.207
Min 25.4
9.155
9.527
0.966 - 1.066
V-I Characteristic
ABSOLUTE MAXIMUM RATINGS @25C
case temp (unless otherwise noted)
SYMBOL
PPP
PM (AV)
Tj
T stg
PARAMETER
Peak Pulse Current
10x1000sec
8-20sec
Steady state power dissipation,
lead length 9.5mm, TL - 85C (note 1)
Junction temperature
Storage temperature
VALUE
2,200
20,000
5.0
-55 to 150
-55 to 150
Units
W
W
W
C
C
Note 1. Mounted on copper pad area 40mm square
Characteristics @25C case temp (unless otherwise noted)
Note 2. Using 10/1000S pulse
DEVICE
TYPE
FB120
FB160
Working
voltage
(Vr)
volts
120
160
Maximum
breakover
Voltage
(Vbo)
volts
170
220
Maximum
leakage
current (Ir)
@ Vr
A
1.0
1.0
Minimum
foldback
voltage Vfb
volts
55
110
Maximum
Peak Pulse
Current (lpp)
@ Vcl Note 2
amps
170
220
Ipp
Irm
Vfb
Vrm
Vbo
Ibo
All dimensions in mm
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