CRxxxx series
Description
The CR range of protectors are based on the proven
technology of the T10 thyristor product. Designed for
transient voltage protection of telecommunications
equipment, it provides higher power handling than a
conventional avalanche diode (TVS) and when compared to
a GDT offers lower voltage clamping levels and infinite surge
life.
Packaged in a transfer molded DO-214AA surface mount
outline designed for high speed pick & place machines used
in today’s surface mount assembly lines.
Electrical Charecteristics
The electrical characteristics of a CRXXXX device is similar
to that of a self gated Triac, but the CR is a two terminal
device with no gate. The gate function is achieved by an
internal current controlled mechanism.
Like the T.T.S. diodes, the CRXXXX has a standoff voltage
(Vrm) which should be equal to or greater than the operating
voltage of the system to be protected. At this voltage (Vrm)
the current consumption of the CRXXXX is negligible and will
not effect the protected system.
When a transient occurs, the voltage across the CRXXXX
will increase until the breakdown voltage (Vbr) is reached. At
this point the device will operate in a similar way to a T.V.S.
device and is in an avalanche mode.
The voltage of the transient will now be limited and will only
increase by a few volts as the device diverts more current.
As this transient current rises, a level of current through the
device is reached (Ibo) which causes the device to switch to
a fully conductive state such that the voltage across the
device is now only a few volts (Vt). The voltage at which the
device switches from the avalanche mode to the fully
conductive state (Vt) is known as the Breakover Voltage
(Vbo). When the device is in the Vt state, high currents can
be deverted without damage to the CRXXXX due to the low
voltage across the device, since the limiting factor in such
devices is dissipated power (V x I).
Resetting of the device to the non conducting state is
controlled by the current flowing through the device. When
the current falls below a certain value, known as the Holding
Current (Ih), the device resets automatically.
As with the avalanche T.V.S. device, if the CRXXXX is
subjected to a surge current which is beyond its maximum
rating, then the device will fail in short circuit mode, this
ensures that the equipment is ultimately protected.
Selecting A CRXXXX
1. When selecting a CRXXXX device, it is important that the
Vrm of the device is equal to or greater than the operating
voltage of the system.
2. The minimum Holding Current (Ih) must be greater than
the current the system is capable of delivering otherwise the
device will remain conducting following a transient condition.
I
T
I
H
VT
I
RM
V
RM
V
BR
V
BO
MIN
I
BO
V-I Graph
Illustrating Symbols
and Terms for
the CR Surge
Protection Device.
The CRXXXX Range Can Be Used to Protect Against Surges As Defined In The Following International Standards.
SA
FCC Rules Part 68/D
Bellcore Specification
Metallic
Longitudinal
TR-NWT-001089
10/560µs
10/160µs
10/1000µs
2/10µs
100v/µs
100/700µs
5/310µs
10/700µs
5/310µs
0.5/700µs
0.8/310µs
8/20µs
1-2/50µs
10/700µs
5/310µs
50A
100A
37A
-
1KV
-
-
-
-
1.0KV
25A
-
-
1000V
25A
SB
100A
150A
75A
-
1KV
1.5KV
38A
2KV
50A
1.0KV
25A
100A
300V
10000V
25A
SC
100A
200A
100A
500A
1KV
1.5KV
38A
4.0KV
100A
4.0KV
100A
250A
500V
4000V
100A
ITU K-17 (Formerly CCITT)
VDE 0433
C-NET 131-24
IEC 1000-4-5
ITU K-20
(Formerly CCITT)
Voltage Wave Form
Current Wave Form
Voltage Wave Form
Current Wave Form
Voltage Wave From
Current Wave Form
(Discharge through 2Ω impendance) I
Voltage Wave Form
Voltage Wave Form
Current Wave Form
52
w w w. l i t t e l f u s e . c o m
CRxxxx series
Specifications
Electrical Charecteristics (Tj=25°C)
SYMBOL
V
RM
V
BR
V
BO
V
T
PARAMETER
Stand-off Coltage
Breakdown Voltage
Breakover Voltage
On-State Voltage
SYMBOL
I
RM
I
BO
I
H
PARAMETER
Stand-off Current
Breakover Current
Holding Current
THERMAL DATA
T stg
Storage and Operating Junction Temperature range
Tj
TL
Maximum Temperature For Soldering
(For period of 10 seconds max)
VALUE
-40 to +150
150
230
UNIT
°C
°C
°C
Stock
Number
Device
Code
Reverse
Stand-off
Voltage
25
58
65
75
90
120
140
160
190
220
275
320
25
58
65
75
90
120
140
160
190
220
275
320
25
58
65
75
90
120
140
160
190
220
275
320
Maximum
Reverse
Leakage
µA
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Maximum
Breakover
Voltage
@Ibo
40
77
88
98
130
160
180
220
260
300
350
400
40
77
88
98
130
160
180
220
260
300
350
400
40
77
88
98
130
160
180
220
260
300
350
400
Maximum
Breakover
Current
mA
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
800
Minimum
Holding
Current
mA
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
150
Maximum
On-State
Voltage
@1A
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Typical
Capacitance
@1MHz 2v bias
pF
100
60
60
60
60
40
40
40
30
30
30
30
100
60
60
60
60
40
40
40
30
30
30
30
200
120
120
120
120
80
80
80
60
60
60
60
MAXIMUM RATINGS
SUFFIX
SA
Ipp 10x160µs Amps
Ipp 10x560µs Amps
I
TSM
60Hz Amps
DI/dt Amps/µs
100
50
20
500
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
0300
0640
0720
0800
1100
1300
1500
1800
2300
2600
3100
3500
0300
0640
0720
0800
1100
1300
1500
1800
2300
2600
3100
3500
0300
0640
0720
0800
1100
1300
1500
1800
2300
2600
3100
3500
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
030A
064A
072A
080A
110A
130A
150A
180A
230A
260A
310A
350A
030B
064B
072B
080B
110B
130B
150B
180B
230B
260B
310B
350B
030C
064C
072C
080C
110C
130C
150C
180C
230C
260C
310C
350C
MAXIMUM RATINGS
SUFFIX
SB
Ipp 10x160µs Amps
Ipp 10x560µs Amps
I
TSM
60Hz Amps
DI/dt Amps/µs
150
100
30
500
MAXIMUM RATINGS
SUFFIX
SC
Ipp 2x10µs Amps
Ipp 10x160µs Amps
Ipp 10x560µs Amps
I
TSM
60Hz Amps
dI/dt Amps/µs
500
200
100
60
500
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53
CRxxxx series
°
CRXXXXSB
CRXXXXSC
CRXXXXSA
°
PULSE WAVE FORM (10/10000µS)
I
PP
- Percentage peak current - %I
PP
tr
100
t
2
90
tr = 1.25 x (t
2
- t
1
) =10µs
50
td = 1000µs
10
t
1
1
2
3
4
°
t - Time
- m S e c
PEAK SURGE ON-STATE CURRENT
VS. SURGE CURRENT DURATION
Peak Current Surge (Non-Repetitive)
On-State Current (RMS) - Amps
100
80
60
50
40
30
20
10
8
6
5
4
3
2
1
1
2
3 4 5
10
20 30 40 50
100
200 300
1000
CRXXXXSB
CRXXXXSC
CRXXXXSA
Surge Current Duration - full cycles @ 60H
Z
SINUSOIDAL
10x160µs PULSE WAVE FORM
Ipp - Peak Pulse Current - %Ipp
Peak Value - Ipp
TEST WAVEFORM
PARAMETER
tr = 10 sec
td = 160 sec
Ipp t
= d
2
10x560µs PULSE WAVE FORM
Ipp - Peak Pulse Current - %Ipp
Peak Value - Ipp
TEST WAVEFORM
PARAMETER
tr = 10 sec
td = 560 sec
Ipp t
= d
2
Half Value =
Half Value =
10x160 Waveform
10x560 Waveform
0
80
160 240
320 400
480
0 280
560
840 1,120 1,400 1,680
t - Time - Sec
t - Time - Sec
54
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