307C Overcurrent Thermistors
PTCR Overcurrent Protection
Vishay Cera-Mite
Table 3
CUSTOM PTCR PELLET
DESIGN CAPABILITY
RATING CHART FOR CUSTOM PELLETS
DISC DIAMETER (2.5mm THICK) 6.5mm
• Vishay Cera-Mite will customize
solid state overcurrent protector
PTCRs to your exact requirements
for telecommunication, power
supply, or general electronic
use. Providing great flexibility to
establish specific voltage, hold
current, time-trip characteristic, and
ambient temperature values.
8mm
9.5mm
11mm
12.5mm 14.5mm
Continuous Voltage Rating (rms)
(proportional to resistance)
100 – 300 100 – 300100 – 300 100 – 300 100 – 300 50 - 300
Resistance Range @ 25°C (ohms) 10 to 35 7 to 25 5 to 20
4 to 17
2 to 15
1 to 10
Continuous Carry Current (mA)
Ambient 25° to 50°C (inversely
proportional to resistance)
60 – 120 75 – 175 100 – 200 110 – 250 130 – 400 150 – 600
Approximate Minimum Power
to Trip or Reset (watts)
• Each device must be evaluated
and ratings established per appli-
cation. Mechanical packaging
influences performance ratings.
0.4
0.5
0.6
0.7
0.8
0.9
Interrupting Capability
A. Repetitive (25 to 300 VRMS
Peak power in watts
)
600
2.5
700
4.0
800
7.5
900
15
1000
20
1100
30
B. Non-repetitive (for 10 ohm
pellet) I2 t Let Through
Maximum Safe Interrupting
Voltage (rms) (voltage rating
is proportional to resistance)
300
350
400
450
500
600
Rating applies to pellets with silver electrodes and pressure connections.
TRANSIENT VOLTAGE &
CURRENT
Fig P-11
Because of the thermal storage
capacity of the ceramic PTCR,
transient surges do not cause tripping.
The PTCR is considered to be
transparent to these low energy
transients. Fig P-11 shows a typical
test circuit for such transients.
1000
10 x 1000µ sec.
PTCR
± 1000V peak
Pass-Thru Pulse
Table 4
WIRE LEADED PTC
TELECOM THERMISTORS
TELECOM CURRENT LIMITERS
Resettable current limiters featuring
hold current and voltage ratings for
telecommunication applications.
VISHAY
CERA-MITE
PART
Note 1
Hold and trip
currents specified at
25°C ambient.
HOLD (IH) TRIP (IT) RESISTANCE SWITCH SIZE (D)
MAX.
CURRENT CURRENT
R25
TOL. TEMP. NOMINAL VOLTAGE
VRMS
mA
mA
Ohms
%
°C
mm
NUMBER
70
140
200
200
220
220
240
240
240
260
240
240
300
240
250
270
300
340
220
250
100 25
120
80
105
80
105
80
105
120
80
120
105
90
80
105
80
6.5
8
8
8
8
8
8
8
8
8.7
8.7
8.7
9.5
9.5
9.5
9.5
11.2
14.5
14.5
265
220
220
220
220
220
220
220
120
250
250
110
220
220
220
220
220
300
265
307C1418
307C1305
307C1506
307C1354
307C1514
307C1129
307C1296
307C1470
307C1421
307C1505
307C1501
307C1439
307C1465
307C1507
307C1469
307C1233
307C1234
307C1262
307C1254
Fig P-12
100
100
110
110
120
120
120
130
120
120
150
120
125
135
150
170
110
125
20
30
18
25
15
20
25
13
39
25
12
15
20
10
10
10
23
18
20
20
20
20
20
20
20
20
30
25
20
25
20
25
20
20
20
25
Note 2
Tinned Copper Wire
22 AWG Standard
20 AWG on D=14.5mm
R
is nominal zero
25
power resistance
(± 25%) at 25°C.
5mm
max
Note 3
P/N suffix describes
options including:
Tape & Reel
Wire Size
Wire Style &
Length
32mm min
4.5mm
max
D
LS = 5mm
105
105
80
Lead Spacing
Coating Material
80
Note 1
Note 2
Note 3
Rated Voltage = 60Vdc; Rated Current = 3A at rated voltage.
www.vishay.com
14
Document Number: 23089
Revision 14-May-02
ceramite.support@vishay.com