137
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Varistor Products
2
V
ARIST
OR
PR
ODUCTS
Low Profile
RA Varistor Series
The RA Series transient surge suppressors are varistors (MOVs)
supplied in a low-profile box that features a precise seating plane to
increase mechanical stability for secure circuit-board mounting. This
feature makes these devices suitable for industrial applications critical
to vibration. Their construction permits operation up to 125
o
C (ambient)
without derating.
The RA series are available in voltage ratings up to 275V VM(AC)RMS,
and energy levels up to 140J. These varistors are used in automotive,
motor-control, telecommunication, and military applications.
See RA Series Device Ratings and Specifications table for part number
and brand information.
Features
Low Profile Outline with Precise Seating Plane
No Derating up to 125
o
C Ambient
Wide Operating Voltage Range
VM(AC)RMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4V to 275V
VM(DC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5V to 369V
High Energy Absorption Capability W TM . . . . . . . . . . . . . up to 140J
3 Model Sizes Available . . . . . . . . . RA8, RA16, and RA22
In-Line Leads
AGENCY APPROVALS:
Recognized under the components program of
Underwriters Laboratories. Certified by CSA.
AGENCY FILE NUMBERS:
UL E75961, E56529, E135010;
CSA LR91788.
138
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Varistor Products
RA Varistor Series
Absolute Maximum Ratings
For ratings of individual members of a series, see Device Ratings and Specifications chart
Continuous:
Steady State Applied Voltage:
AC Voltage Range (VM(AC)RMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 to 275
10to 275
4 to 275
V
DC Voltage Range (VM(DC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 to 369
14 to 369
18 to 369
V
Transient:
Peak Pulse Current (ITM)
For 8/20s Current Wave (See Figure 2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 to1200
1000 to 4500
2000 to 6500
A
Single Pulse Energy Range (Note 1)
For 10/1000s Current Wave (WTM ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 to 23
3.5 to 75
70 to 160
J
Operating Ambient Temperature Range (TA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to 125
-55 to -125
-55 to -125
O
C
Storage Temperature Range (TSTG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to 150
-55 to 150
-55 to 150
O
C
Temperature Coefficient (
V) of Clamping Voltage
(VC) at Specified Test Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <0.01
<0.01
<0.01
%/
O
C
Hi-Pot Encapsulation (Isolation Voltage Capability)
(Dielectric must withstand indicated DC voltage for
one minute per MIL-STD 202, Method 301)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5000
5000
5000
V
Insulation Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000
1000
1000
M
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device
at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Device Ratings and Specifications
(Note 1)
RA8 SERIES RA16 SERIES RA22 SERIES UNITS
Low Profile
PART
NUMBER
BRAND
MAXIMUM RATINGS (125
o
C)
SPECIFICATIONS (25
o
C)
CONTINUOUS
TRANSIENT
VARISTOR VOLTAGE AT
1mA DC TEST
CURRENT
MAX CLAMPING
VOLTAGE V
C
AT
TEST CURRENT
(8/20
s)
TYPICAL
CAPACI-
TANCE
V
RMS
V
DC
ENERGY
(10/1000
s)
PEAK
CURRENT
(8/20
s)
V
M(AC)
V
M(DC)
W
TM
I
TM
MIN
V
N(DC)
MAX
V
C
I
P
f = 1MHz
(V)
(V)
(J)
(A)
(V)
(V)
(V)
(V)
(A)
(pF)
RA8 SERIES
V8RA8
8R
4
5.5
0.4
150
6
8.2
11.2
22
5
3000
V12RA8
12R
6
8
0.6
150
9
12
16
34
5
2500
V18RA8
18R
10
14
0.8
250
14.4
18
21.6
42
5
2000
V22RA8
22R
14
18
(Note 3)
10
(Note 2)
250
18.7
22
26
47
5
1600
V27RA8
27R
17
22
1.0
250
23
27
31.1
57
5
1300
V33RA8
33R
20
26
1.2
250
29.5
33
36.5
68
5
1100
V39RA8
39R
25
31
1.5
250
35
39
43
79
5
900
V47RA8
47R
30
38
1.8
250
42
47
52
92
5
800
V56RA8
56R
35
45
2.3
250
50
56
62
107
5
700
V68RA8
68R
40
56
3.0
250
61
68
75
127
5
600
V82RA8
82R
50
66
4.0
1200
74
82
91
135
10
500
V100RA8
100R
60
81
5.0
1200
90
100
110
165
10
400
V120RA8
120R
75
102
6.0
1200
108
120
132
205
10
300
V150RA8
150R
95
127
8.0
1200
135
150
165
250
10
250
V180RA8
180R
115
153
10.0
1200
162
180
198
295
10
200
V200RA8
200R
130
175
11.0
1200
184
200
228
340
10
180
V220RA8
220R
140
180
12.0
1200
198
220
242
360
10
160
V240RA8
240R
150
200
13.0
1200
212
240
268
395
10
150
V270RA8
270R
175
225
15.0
1200
247
270
303
455
10
130
V360RA8
360R
230
300
20.0
1200
324
360
396
595
10
100
139
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Varistor Products
2
V
ARIST
OR
PR
ODUCTS
Low Profile
RA Varistor Series
Device Ratings and Specifications
(Note 1) (Continued)
V390RA8
390R
250
330
21.0
1200
354
390
429
650
10
90
V430RA8
430R
275
369
23.0
1200
389
430
473
710
10
80
RA16 SERIES
V18RA16
18R16
10
14
3.5
1000
14.4
18
21.6
39
10
11000
V22RA16
22R16
14
18
(Note 3)
50
(Note 2)
1000
18.7
22
26
43
10
9000
V27RA16
27R16
17
22
5.0
1000
23
27
31.1
53
10
7000
V33RA16
33R16
20
26
6.0
1000
29.5
33
36.5
64
10
6000
V39RA16
39R16
25
31
7.2
1000
35
39
43
76
10
5000
V47RA16
47R16
30
38
8.8
1000
42
47
52
89
10
4500
V56RA16
56R16
35
45
10.0
1000
50
56
62
103
10
3900
V68RA16
68R16
40
56
13.0
1000
61
68
75
123
10
3300
V82RA16
82R16
50
66
15.0
4500
74
82
91
145
50
2500
V100RA16
100R16
60
81
20.0
4500
90
100
110
175
50
2000
V120RA16
120R16
75
102
22.0
4500
108
120
132
205
50
1700
V150RA16
150R16
95
127
30.0
4500
135
150
165
255
50
1400
V180RA16
180R16
115
153
35.0
4500
162
180
198
300
50
1100
V200RA16
200R16
130
175
38.0
4500
184
200
228
340
50
1000
V220RA16
220R16
140
180
42.0
4500
198
220
242
360
50
900
V240RA16
240R16
150
200
45.0
4500
212
240
268
395
50
800
V270RA16
270R16
175
225
55.0
4500
247
270
303
455
50
700
V360RA16
360R16
230
300
70.0
4500
324
360
396
595
50
550
V390RA16
390R16
250
330
72.0
4500
354
390
429
650
50
500
V430RA16
430R16
275
369
75.0
4500
389
430
473
710
50
450
RA22 SERIES
V24RA22
24R22
14
18
(Note 3)
100.0
(Note 2)
2000
19.2
24
(Note 4)
26
43
20
18000
V36RA22
36R22
23
31
160.0
(Note 2)
2000
32
36
(Note 4)
40
63
20
12000
V200RA22
200R22
130
175
70.0
6500
184
200
228
340
100
1900
V240RA22
240R22
150
200
80.0
6500
212
240
268
395
100
1600
V270RA22
270R22
175
225
90.0
6500
247
270
303
455
100
1400
V390RA22
390R22
250
330
130.0
6500
354
390
429
650
100
1000
V430RA22
430R22
275
369
140.0
6500
389
430
473
710
100
900
NOTES:
1. Average power dissipation of transients not to exceed 0.25W for RA8 Series, 0.60W for RA16 Series, or 1.0W for RA22 Series.
2. Energy ratings for impulse duration of 30ms minimum to one half of peak current value.
3. Also rated to withstand 24V for 5 minutes.
4. 10mA DC Test Current.
Under UL File No. E75961 as a recognized component. CSA approved File No. LR91788.
PART
NUMBER
BRAND
MAXIMUM RATINGS (125
o
C)
SPECIFICATIONS (25
o
C)
CONTINUOUS
TRANSIENT
VARISTOR VOLTAGE AT
1mA DC TEST
CURRENT
MAX CLAMPING
VOLTAGE V
C
AT
TEST CURRENT
(8/20
s)
TYPICAL
CAPACI-
TANCE
V
RMS
V
DC
ENERGY
(10/1000
s)
PEAK
CURRENT
(8/20
s)
V
M(AC)
V
M(DC)
W
TM
I
TM
MIN
V
N(DC)
MAX
V
C
I
P
f = 1MHz
(V)
(V)
(J)
(A)
(V)
(V)
(V)
(V)
(A)
(pF)
140
w w w . l i t t e l f u s e . c o m
Varistor Products
RA Varistor Series
Power Dissipation Ratings
Should transients occur in rapid succession, the average power dissipation
required is simply the energy (watt-seconds) per pulse times the number
of pulses per second. The power so developed must be within the specifi-
cations shown on the Device Ratings and Specifications table for the
specific device. Furthermore, the operating values need to be derated
at high temperatures as shown in Figure 1. Because varistors can only
dissipate a relatively small amount of average power they are, therefore,
not suitable for repetitive applications that involve substantial amounts of
average power dissipation.
FIGURE 1. CURRENT, ENERGY AND POWER DERATING
CURVE
100
90
80
70
60
50
40
30
20
10
0
-55
50
60
70
80
90
100
110
120
130
140 150
AMBIENT TEMPERATURE (
o
C)
PERCENT OF RA
TED
V
ALUE
100
90
50
10
O
1
T
T
1
T
2
TIME
PERCENT OF PEAK
V
ALUE
Low Profile
O
1
= Virtual Origin of Wave
T = Time From 10% to 90% of Peak
T
1
= Virtual Front time = 1.25 t
T
2
= Virtual Time to Half Value (Impulse Duration)
Example: For an 8/20
s Current Waveform:
8
s = T
1
= Virtual Front Time
20
s = T
2
= Virtual Time to Half Value
FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM
141
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Varistor Products
2
V
ARIST
OR
PR
ODUCTS
Low Profile
RA Varistor Series
Transient V-I Characteristics Curves
(Continued)
FIGURE 5. CLAMPING VOLTAGE FOR V18RA16 - V68RA16
600
500
400
300
200
100
90
80
70
60
50
40
30
20
10
-3
10
-2
10
-1
10
0
10
1
10
2
10
3
PEAK AMPERES (A)
MAXIMUM PEAK
V
O
L
TS (V)
V68RA16
V56RA16
V47RA16
V39RA16
V33RA16
V27RA16
V22RA16
V18RA16
MAXIMUM CLAMPING VOLTAGE
18 TO 68V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
FIGURE 3. CLAMPING VOLTAGE FOR V8RA8 - V68RA8
600
500
400
300
200
100
90
80
70
60
50
40
30
20
10
10
-3
10
-2
10
-1
10
0
10
1
10
2
10
3
PEAK AMPERES (A)
MAXIMUM PEAK
V
O
L
TS (V)
V68RA8
V56RA8
V47RA8
V39RA8
V33RA8
V27RA8
V22RA8
V18RA8
V12RA8
V8RA8
MAXIMUM CLAMPING VOLTAGE
8 T
O
68V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
FIGURE 4. CLAMPING VOLTAGE FOR V82RA8 - V430RA8
MAXIMUM PEAK
V
O
L
TS (V)
PEAK AMPERES (A)
10
-2
10
-1
10
0
10
1
10
2
10
3
10
-3
V180RA8
V150RA8
V120RA8
V100RA8
MAXIMUM CLAMPING VOLTAGE
MODEL SIZE 5 x 8mm
82 TO 430V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
4,000
3,000
2,000
1,000
900
800
700
600
500
400
300
200
100
10
4
V82RA8
V270RA8
V360RA8
V220RA8
V200RA8
V240RA8
V430RA8
V390RA8
FIGURE 6. CLAMPING VOLTAGE FOR V82RA16 - V430RA16
MAXIMUM PEAK
V
O
L
TS (V)
PEAK AMPERES (A)
10
-2
10
-1
10
0
10
1
10
2
10
3
10
-3
V180RA16
V150RA16
V120RA16
V100RA16
MAXIMUM CLAMPING VOLTAGE
MODEL SIZE 5 x 8mm
82 TO 430V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
4,000
3,000
2,000
1,000
900
800
700
600
500
400
300
200
100
10
4
V82RA16
V270RA16
V360RA16
V220RA8
V200RA8
V240RA16
V430RA16
V390RA16
FIGURE 7. CLAMPING VOLTAGE FOR V24RA22 - V36RA22
300
200
100
90
80
70
60
50
40
30
20
MAXIMUM PEAK
V
O
L
TS (V)
PEAK AMPERES (A)
10
-2
10
-1
10
0
10
1
10
2
10
3
10
-3
10
4
V36RA22
V24RA22
MAXIMUM CLAMPING VOLTAGE
24 TO 36V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
FIGURE 8. CLAMPING VOLTAGE FOR V200RA22 - V430RA22
MAXIMUM PEAK
V
O
L
TS (V)
PEAK AMPERES (A)
10
-2
10
-1
10
0
10
1
10
2
10
3
10
-3
4,000
3,000
2,000
1,000
900
800
700
600
500
400
300
200
100
10
4
MAXIMUM CLAMPING VOLTAGE
200 TO 430V
N(DC)
RATING
T
A
= -55
o
C TO 125
o
C
V430RA22
V390RA22
V270RA22
V240RA22
V200RA22
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