Gas Discharge Tubes
SL1021A/B Series
SL1021A/B Series
Description
RoHS
GDT circuit protection devices dissipate electrical
surge energy safely within a contained plasma gas.
Commonly used to help protect sensitive telecom
and networking equipment and lines, GDTs protect
from damage that may result from lightning strikes
and equipment switching operations.
The Littelfuse GDT series described in this document
are available in a variety of leaded and surface mount
forms and offered with and without optional fail-safe
clip. Please refer to the electrical specifications,
dimension and packaging options section of this
document for additional information.
Agency Approvals
AGENCY
AGENCY FILE NUMBER
E128662
SL1021A/B Series:
SL1021A/B series GDTs are designed to offer high
levels of performance on fast rising transients in the
range of 100V/μS to 1KV/μS, which are those most
likely created by induced lightning disturbances.
These devices feature ultra low capacitance (typically
1.5pF or less) and are extremely robust with SL1021A
devices able to divert a 10,000 Amp pulse without
destruction, and SL1021B suffix devices able to divert
a 20,000 Amp pulse without destruction.
These series offer optimized internal geometry which
provide low insertion loss at high frequencies, ideal
for the protection of broadband and other high speed
transmission equipment.
Product Characteristics
3 Electrode GDT Graphical Symbol
a
b
a = TIP
b = RING
e = GROUND
(center electrode)
e
Features
• RoHS compliant
• Low insertion loss
• Excellent response to
fast rising transients
• Ultra low capacitance
• 10KA (A suffix devices) /
20KA (B suffix devices)
surge capability tested
with 8/20μs pulse as
defined by IEC 61000-4-5
• Available with thermal
failsafe option (add ‘F’
suffix to part number)
Materials
Dull Tin Plate 17 ± 12.5 Microns.
.5
with ceramic insulator
‘LF’ mark, voltage& date code:
SL1021A
- Red/White
text
SL1021B
- Blue/White
text
~ 1Amp
~60-200 Volts
-40 to +90°C
< 0.2µSec
(Tested to ITU-T Rec. K.12)
~10 to 35 Volts
<150mS
(Tested to ITU-T Rec. K.12)
Product Marking
Glow to arc
transition current
Glow Voltage
Storage and Operation
Temperature
Applications
SL1021:
• Broadband equipment
• ADSL equipment
• XDSL equipment
• Satellite and CATV
equipment
• Splitters
• General telecom
equipment
• Telecom network
interfaces
• Telephone line cards
• Repeaters
• Modems
• Line test equipment
Transverse Voltage
(Delay Time)
Arc Voltage
Holdover Voltage
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/12/17
Gas Discharge Tubes
SL1021A/B Series
Electrical Characteristics
Device Specifications
(at 25°C)
Part
Number
SL1021B075
SL1021A090
SL1021B090
SL1021A145
SL1021B145
SL1021A150
SL1021B150
SL1021A200
SL1021A230
SL1021B230
SL1021A250
SL1021B250
SL1021A260
SL1021B260
SL1021A300
SL1021B300
SL1021A350
SL1021B350
SL1021A400
SL1021B400
SL1021A420
SL1021B420
SL1021A450
SL1021B450
SL1021A500
SL1021B500
SL1021A600
Life Ratings
Capaci-
tance
(@1Mhz)
DC Voltage
100V/Sec.
MIN
TYP
MAX
DC
Voltage
100 V/
μSec.
DC
Voltage
1kV/
μSec.
Insulation
Resistance
MIN
AC
Current
50Hz
1Sec.x10
1
Surge
Current
8/20μSec
x10
1
Max
Single
Surge
8/20μSec
1
Max Single
Surge
10/350μSec
1
Surge Life
10/1000
μSecx300
1
60
72
116
120
150
184
200
210
240
280
320
345
360
400
480
75
90
145
150
200
230
250
260
300
350
400
420
450
500
600
90
108
174
180
250
276
300
310
360
420
480
850
500
540
600
720
900
950
1000
450
500
650
>10
10
Ω
(at 50V)
4kA
2
5kA
3
600
650
500
550
650
700
700
850
900
<1.5pF
>10
10
Ω
(at 100V)
10Amps
10kA
2
20kA
3
15kA
2
25kA
3
200Amps
2.5kA
2
5kA
3
950
1000
1100
1200
NOTES:
1. Total current through centre electrode, tested in accordance with ITU-T Rec K.12
2. SL1021A series
3. SL1021B series
Additional Information
Datasheet
SL1021A
Resources
SL1021A
Samples
SL1021A
Datasheet
SL1021B
Resources
SL1021B
Samples
SL1021B
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/12/17
Gas Discharge Tubes
SL1021A/B Series
Time vs. Current for Failsafe
60
30
20
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
SL102xA with Failsafe
SL102xB or PMT8 500 Volt Higher Melting Point Solder
SL102xB or PMT8 350 Volt Higher Melting Point Solder
SL102xB or PMT8 90 Volt Higher Melting Point Solder
Voltage vs. Time Characteristic
Max dynamic breakover
voltage
Voltage
(V)
Hold-over voltage
On-State voltage
0.5 1
2
5
10
15
30
0
200
400
600
Time (ns)
800
1000
1200
Soldering Parameters - Reflow Soldering (Surface Mount Devices)
Reflow Condition
- Temperature Min (T
s(min)
)
Pre Heat
- Temperature Max (T
s(max)
)
- Time (Min to Max) (t
s
)
Average ramp up rate (Liquidus Temp
(T
L
) to peak
T
S(max)
to T
L
- Ramp-up Rate
Reflow
- Temperature (T
L
) (Liquidus)
- Temperature (t
L
)
Pb – Free assembly
150°C
60 – 180 secs
3°C/second max
5°C/second max
217°C
60 – 150 seconds
260
+0/-5
T
P
T
L
Temperature
t
P
Ramp-up
Critical Zone
T
L
to T
P
200°C
T
S(max)
T
S(min)
Preheat
t
L
Ramp-down
t
S
time to peak temperature
(t 25ºC to peak)
25
Time
Peak Temperature (T
P
)
Time within 5°C of actual peak
Temperature (t
p
)
Ramp-down Rate
Time 25°C to peak Temperature (T
P
)
Do not exceed
°C
10 – 30 seconds
6°C/second max
8 minutes Max.
260°C
Soldering Parameters - Hand Soldering
Solder Iron Temperature: 350° C +/- 5°C
Heating Time: 5 seconds max.
Soldering Parameters - Wave Soldering (Thru-Hole Devices)
300
Recommended Process Parameters:
Wave Parameter
Preheat:
(Depends on Flux Activation Temperature)
(Typical Industry Recommendation)
Temperature (°C) - Measured on bottom side of board
280
260
240
220
200
180
160
140
120
100
80
60
40
20
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
10
20
30
40
50
60
70
80
90
0
0
Lead-Free Recommendation
Temperature Minimum:
Temperature Maximum:
Preheat Time:
Solder Pot Temperature:
Solder Dwell Time:
100
°
C
150
°
C
60-180 seconds
280
°
C Maximum
2-5 seconds
Note: Surge Arrestors with a Failsafe mechanism should be
individually examined after soldering
Cooling Time
Dwell Time
Time (Seconds)
Preheat Time
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/12/17
Type 04 / R
11.8
[0.464]
10.10
[0.398]
9.0
[0.354]
8.1.
[0.319]
Type 01 / C
0.3mm
Minimum
Gap
[0.354]
10.10
[0.398]
8.1
[0.319]
Gas Discharge Tubes
SL1021A/B Series
15
[0.590]
16.8
[0.661]
1.0 DIA.
[0.039]
0.3mm
Minimum
Gap
9.9
[0.354]
9.9
[0.354]
4.4
[0.173]
Type 60
4.4± 0.3
[0.173± 0.12]
10.0 ± 0.3
[0.394 ± 0.019]
7.7 ± 0.3
[0.303 ± 0.019]
Ø7.0 ± 0.1
[0.275 ± 0.004]
Device Dimensions
Shaped Radial Leaded Devices:
11.8
Type 05 / P
[0.464]
12.4 ± 1
[0.488 ± 0.039]
4.4± 0.3
[0.173± 0.12]
NOTE: Failsafe option dimensions shown in
green.
Mounting Area
9.0
[0.354]
8.1.
[0.319]
Mounting Area
Mounting Area
9.0
[0.354]
9.0
[0.354]
Mounting Area
8.1.
9.0
[0.319]
8.1.
[0.354]
[0.319]
8.1.
[0.319]
Core Devices:
Type 01 / C
Type 01 / C
Type 01 / C
Mounting Area
SIDE VIEW
TOP VIEW
11.8
Mounting Area
9.0
[0.464]
11.8
[0.354]
9.0
[0.464]
[0.354]
2.2 ± 0.0
10.10
Mounting Area
8.1
11.8
[0.087 ± 0.000]
[0.398]
10.10
9.0
[0.319]
8.1
[0.464]
[0.398]
1.2 ± 0.0
[0.354]
1.2 ± 0.0
0.3mm
[0.047 ± 0.000]
[0.047 ± 0.000]
[0.319]
10.10
Minimum
8.1
0.3mm
[0.398]
Gap
[0.319]
Minimum
Gap
0.3mm
Minimum
9.9
8.5 ± 0.0
Gap
6.0 ± 0.0
[0.354]
9.9
[0.236 ± 0.000]
[0.335 ± 0.000]
[0.354]
9.9
[0.354]
PROFILE VIEW
8.3 +0.3/-0.0
[0.327
+0.019/-0.00]
8.0 +0.3/-0.1
[0.315
+0.019/-0.004]
Type 04 / R
Type
0.3mm
R
04 /
Type 04 / R
0.3mm
Minimum
0.3mm
Gap
Minimum
15
Gap
0.3mm
[0.590]
Minimum
Gap
4.4 15
[0.590] 15
[0.173]
[0.590]
15
[0.590]
5.5± 0.3
4.4
[0.216± 0.12]
[0.173] 4.4
[0.173]
4.4
[0.173]
4.4± 0.3
[0.173± 0.12] 0.3
4.4±
[0.173± 0.12]
4.4± 0.3
[0.173± 0.12]
Minimum
Gap
12.4 ± 1
10.10
[0.488 ± 0.039]
12.4
[0.398] ± 1
[0.488 ± 0.039]
11.8
12.4
[0.464]
± 1
11.8
[0.488 ± 0.039]
[0.464]
10.10
11.8
[0.398]
10.10
[0.464]
[0.398]
10.10
[0.398]
9.9
[0.354]
9.9
[0.354]
9.9
[0.354]
16.8 9.9
[0.661] [0.354]
1.0 DIA.
[0.039]
10.75 ± 0.0
[0.423 ± 0.000]
16.8
[0.661]
5.5± 0.3
16.8
[0.661]
[0.216± 0.12]
16.8
[0.661]
4.4± 0.3
[0.173± 0.12]
4.4± 0.3
[0.173± 0.12]
4.4± 0.3
[0.173± 0.12]
Mounting Area
Mounting Area
9.0
[0.354]
9.0
[0.354]
Mounting
Mounting Area Area
8.1.
9.0
9.0
[0.319]
8.1.
[0.354] [0.354]
[0.319]
8.1.
8.1 DIA. MAX.
[0.319]
[0.319]
9.9
[0.354]
9.9
[0.354]
9.9
[0.354]
1.0 DIA.
[0.039]DIA.
1.0
[0.039]
1.0 DIA.
[0.039]
SOLDERING PAD LAYOUT
10.0 ± 0.3
[0.394
10.0 ± 0.3
± 0.019]
[0.394 ± 0.019]
Ø7.0 ± 0.1
[0.275
10.0 ± 0.3
± 0.004]
Ø7.0 ± 0.1
[0.394 ± 0.019]
[0.275 ± 0.004]
Ø7.0 ± 0.1
[0.275 ± 0.004]
Overall Product Space
DO NOT ENCROACH
Type 60
Type 60
Straight
60
Type
Radial Leaded Devices:
8.3 +0.3/-0.0
[0.327
8.3 +0.3/-0.0
+0.019/-0.00]
[0.327
+0.019/-0.00]
8.3 +0.3/-0.0
[0.327
+0.019/-0.00]
14.7
[0.579]
11.8
[0.464]
PROFILE VIEW
PROFILE VIEW
7.7 ± 0.3
[0.303 ± 0.019]
7.7 ± 0.3
[0.303 ± 0.019]
7.7 ± 0.3
[0.303 ± 0.019]
Type 14 / X
Type 05 / P
Type 05 / P
Type 05 / P
0.3mm
Minimum
0.3mm
Gap
Minimum
Gap
0.3mm
0.3mm
Minimum Minimum
Gap
Gap
12.4 ± 1
[0.488 ± 0.039]
12.4 ± 1
[0.488 ± 0.039]
11.8
50 ± 3
[0.464]
± 1
12.4
11.8
[1.968 ± 0.118 ]
[0.464]
[0.488 ± 0.039]
10.10
11.8
11.8
[0.398]
10.10
[0.464]
[0.464]
[0.398]
10.10
10.10
[0.398]
[0.398]
Type 06 / Y
10.10
[0.398]
SIDE VIEW
SIDE VIEW
8.0 +0.3/-0.1
[0.315
8.0 +0.3/-0.1
+0.019/-0.004]
[0.315
Mounting Area
+0.019/-0.004]
9.0
8.0 +0.3/-0.1
[0.354]
[0.315
+0.019/-0.004]
8.1 DIA. MAX.
TOP VIEW
[0.319]
TOP VIEW
0.3mm
Minimum
Gap
PROFILE VIEW
15
[0.590] 15
[0.590]
15
[0.590]
22 4.4
[0.173] 4.4
[0.866]
[0.173]
4.4
[0.173]
5.5± 0.3
[0.216± 0.12] 0.3
5.5±
[0.216± 0.12]
5.5± 0.3
[0.216± 0.12]
16.8 23.8
[0.937]
[0.661]
16.8
[0.661]
16.8
[0.661]
5.5± 0.3
[0.216± 0.12]
5.5± 0.3
[0.216± 0.12]
5.5± 0.3
[0.216± 0.12]
1.0 DIA.
[0.039]DIA.
1.0
[0.039]
1.0 DIA.
1.0 DIA..
[0.039] [0.039]
1.2 ± 0.0
[0.047 ± 0.000]
0.0
1.2 ±
[0.047 ± 0.000]
1.2 ± 0.0
[0.047 ± 0.000]
15
6.0 ± 0.0
[0.590]
[0.236 ± 0.000]
0.0
6.0 ±
[0.236 ± 0.000]
6.0 ± 0.0
[0.236 ± 0.000]
2.2 ± 0.0
SIDE VIEW
2.2
± 0.000]
TOP VIEW
[0.087
± 0.0
[0.087 ± 0.000]
1.2 ± 0.0
2.2
9.9
0.0 1.2
± 0.000]
±
[0.047
± 0.0
[0.354]
[0.047
[0.087 ± 0.000] ± 0.000]
1.2 ± 0.0
[0.047 ± 0.000]
8.5 ± 0.0
[0.335 ± 0.000]
8.5 ± 0.0
[0.335 ± 0.000]
8.51.00.0
± DIA.
[0.039]
[0.335 ± 0.000]
Overall Product Space
DO NOT ENCROACH
Overall Product Space
DO NOT ENCROACH
Overall Product Space
DO NOT ENCROACH
16.8
[0.661]
10.75 ± 0.0
[0.423 ± 0.000]
10.75 ± 0.0
[0.423 ± 0.000]
10.75
LAYOUT
SOLDERING PAD
± 0.0
[0.423 ±
6.35 ± 0.5
0.000]
SOLDERING PAD LAYOUT
[0.25 ± 0.25]
SOLDERING PAD LAYOUT
6.35 ± 0.5
[0.25 ± 0.25]
Type 14 / X
Leaded Devices:
Straight "T"
/ X
Type 14
Type 14 / X
50 ± 3
[1.968 ± 50 ± 3]
0.118
[1.968 ± 0.118 ]
11.8
50 ± 3
[0.464]
11.8
[1.968 ± 0.118 ]
[0.464]
10.10
11.8
[0.398]
10.10
[0.464]
[0.398]
10.10
[0.398]
Mounting Area
Mounting Area
9.0
[0.354]
9.0
[0.354]
Mounting Area
8.1 DIA. MAX.
9.0
[0.319] MAX.
8.1
[0.354]
DIA.
[0.319]
8.1 DIA. MAX.
[0.319]
Type 06 / Y
Type 06 / Y
Type 06 / Y
0.3mm
Minimum
0.3mm
Gap
Minimum
Gap
0.3mm
Minimum
Gap
15
[0.590] 15
[0.590]
15
[0.590]
14.7
[0.579]
14.7
[0.579]
11.8
14.7
[0.464]
11.8
[0.579]
[0.464]
10.10
11.8
[0.398]
10.10
[0.464]
[0.398]
10.10
[0.398]
9.9
[0.354]
9.9
[0.354]
9.9
[0.354]
Mounting Area
Mounting Area
9.0
[0.354]
9.0
[0.354]
Mounting Area
8.1 DIA. MAX.
9.0
[0.319] MAX.
8.1 DIA.
[0.354]
[0.319]
8.1 DIA. MAX.
[0.319]
0.3mm
Minimum
0.3mm
Gap
Minimum
Gap
0.3mm
Minimum
Gap
22
[0.866] 22
[0.866]
22
[0.866]
23.8
[0.937]
23.8
[0.937]
23.8
[0.937]
1.0 DIA..
[0.039]
1.0 DIA..
[0.039]
1.0 DIA..
[0.039]
16.8
[0.661]
16.8
[0.661]
16.8
[0.661]
6.35 ± 0.5
[0.25 ± 0.25]
6.35 ± 0.5
[0.25 ± 0.25]
6.35 ± 0.5
[0.25 ± 0.25]
1.0 DIA.
[0.039]DIA.
1.0
[0.039]
1.0 DIA.
[0.039]
6.35 ± 0.5
[0.25 ± 0.25] 0.5
6.35 ±
[0.25 ± 0.25]
6.35 ± 0.5
[0.25 ± 0.25]
Type “R” is available for SL1021B075 device only.
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/12/17
Gas Discharge Tubes
SL1021A/B Series
~2
58
Box (Cardboard)
~58
Tray (PET)
for 50 Pcs.
Sponge (PE Form)
Part Numbering System and Ordering Information
SL102x x xxx x x
Series
SL1021
SL1024
Packaging
~135
PMT8 xxx x x
Series
PMT8
For 'SL1021A/B' device type C, R, P, Y packing
~2
35
Surge Capability
A = 10kA
B = 20kA
Breakdown Voltage
090 = 90V
145 = 145V
150 = 150V
200 = 200V
230 = 230V
250 = 250V
260 = 260V
300 = 300V
350 = 350V
400 = 400V
420 = 420V
450 = 450V
500 = 500V
600 = 600V
Breakdown Voltage
090 = 90V
230 = 230V
250 = 250V
350 = 350V
400 = 400V
Box (Cardboard)
Tray, Cover (PET)
Configuration Code
Configuration Code
(See Device Dimensions section)
C
Y
R
X
P
(See Device Dimensions section)
01
10
04
14
05
60
06
Blank = No Failsafe
F = With Failsafe
~55
Tray, Bottom (PET)
for 100 Pcs.
PE Form
Option Code
Blank = No failsafe
F or G = With Failsafe
Option Code
For 'SL1021A/B' device type X packing
~2
58
Box (Cardboard)
~58
Tray (PET)
for 50 Pcs.
Sponge (PE Form)
~135
35
Device
~2
Type
Description
100pcs/tray x 5 trays per carton
Box (Cardboard)
Quantity
500
500
500
500
250
Type C
Type R
~55
100pcs/tray x 5 trays per carton
Tray, Cover (PET)
Type P
Type Y
Type X
100pcs/tray x 5 trays per carton
100pcs/tray x 5 trays per carton
50pcs/tray x 5 trays per carton
PE Form
Tray, Bottom (PET)
for 100 Pcs.
* Please contact the factory for further packaging information.
Disclaimer Notice -
Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and
test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete
Disclaimer Notice at:
www.littelfuse.com/disclaimer-electronics.
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/12/17
