Self-protecting power resistors
PTC thermistors in plastic case
Series/Type:
Date:
B5920*
June 2008
© EPCOS AG 2008. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
Self-protecting power resistors
PTC thermistors in plastic case
J201, J202, J204
Applications
Inrush current limiter (charging resistor) for
smoothing and DC link capacitors
To replace high-power fixed resistors for
capacitor charging
Dimensional drawing
Features
Self-protecting in case of malfunction of
short-circuit relay or internal short-circuit of
capacitor
Encased thermistor disk with clamp contacts
For high pulse currents and a high number of
operating cycles
Flame-retardant plastic case
Case material UL-listed
Sn-plated lead-free solder pins
Manufacturer's logo and type designation
stamped on in white
RoHS-compatible
Delivery mode
Packed in carton box
General technical data
Operating cycles at V
max
Switching cycles at V
max
Thermal cooling time constant
Heat capacity
Operating temperature range
Operating temperature range
Dimensions in mm
Wiring diagram
(charging of capacitor)
(failure mode)
(typical)
(typical)
(V = 0)
(V = V
max
)
N
c
N
f
τ
th
C
th
T
op
T
op
> 100000
> 10
150
2.0
40/+125
0/+85
cycles
cycles
s
J/K
°C
°C
Electrical specifications and ordering codes
V
max1)
VDC
550
650
800
R
R
Ω
20
56
100
∆R
R
%
30
30
25
T
ref
°C
135
135
130
I
pulse,max
A
p
50
25
20
V
BD
V
> 700
> 700
> 900
Ordering code
B59201J0140B010
B59202J0135B010
B59204J0130B010
1) V
max
: Maximum permissible DC voltage directly applied to the PTC thermistor.
Please read
Cautions and warnings
and
Important notes
at the end of this document.
Page 2 of 7
Self-protecting power resistors
PTC thermistors in plastic case
J201, J202, J204
Characteristics
Minimum resistance of PTC thermistors
versus applied voltage
PTC resistance R
PTC
versus
PTC temperature T
PTC
(measured at low signal voltage)
Switching time t
S
versus switching current I
S
(measured at 25
°C
in still air)
Residual current in high ohmic state I
res
as
function of applied voltage V
PTC
(measured at 25
°C
in still air)
Please read
Cautions and warnings
and
Important notes
at the end of this document.
Page 3 of 7
Self-protecting power resistors
PTC thermistors in plastic case
J201, J202, J204
Calculation of the number of required PTC elements
Number of required PTC elements (connected in parallel) as function of capacitance and charging
voltage of smoothing or DC link capacitor:
N
C
V
C
th
T
ref
T
A,max
Number of required PTC thermistors connected in parallel
Capacitance of smoothing or DC link capacitor in F
Charging voltage of capacitor in V
Heat capacity in J/K
Reference temperature of PTC in
°C
Expected maximum ambient temperature in
°C
In case of large N values the resulting resistance of the parallel PTC network might be too low for
effective limitation of the charging current. In this case a combination of series and parallel
connected PTC thermistors can be used.
Please read
Cautions and warnings
and
Important notes
at the end of this document.
Page 4 of 7
Self-protecting power resistors
PTC thermistors in plastic case
J201, J202, J204
Cautions and warnings
General
EPCOS thermistors are designed for specific applications and should not be used for purposes
not identified in our specifications, application notes and data books unless otherwise agreed
with EPCOS during the design-in-phase.
Ensure suitability of thermistor through reliability testing during the design-in phase. The ther-
mistors should be evaluated taking into consideration worst-case conditions.
Storage
Store thermistors only in original packaging. Do not open the package before storage.
Storage conditions in original packaging: storage temperature 25
°C
... +45
°C,
relative hu-
midity
≤75%
annual mean, maximum 95%, dew precipitation is inadmissible.
Avoid contamination of thermistors surface during storage, handling and processing.
Avoid storage of thermistor in harmful environment with effect on function on long-term opera-
tion (examples given under operation precautions).
Use thermistor within 6 months after delivery.
Handling
PTCs must not be dropped. Chip-offs must not be caused during handling of PTCs.
Components must not be touched with bare hands. Gloves are recommended.
Avoid contamination of thermistor surface during handling.
Soldering (where applicable)
Use rosin-type flux or non-activated flux.
Insufficient preheating may cause ceramic cracks.
Rapid cooling by dipping in solvent is not recommended.
Complete removal of flux is recommended.
Standard PTC heaters are not suitable for soldering.
Mounting
Electrode must not be scratched before/during/after the mounting process.
Contacts and housing used for assembly with thermistor have to be clean before mounting. Es-
pecially grease or oil must be removed.
When PTC thermistors are encapsulated with sealing material, the precautions given in chapter
"Mounting instructions", "Sealing and potting" must be observed.
When the thermistor is mounted, there must not be any foreign body between the electrode of
the thermistor and the clamping contact.
The minimum force of the clamping contacts pressing against the PTC must be 10 N.
During operation, the thermistor’s surface temperature can be very high. Ensure that adjacent
components are placed at a sufficient distance from the thermistor to allow for proper cooling at
the thermistors.
Ensure that adjacent materials are designed for operation at temperatures comparable to the
surface temperature of thermistor. Be sure that surrounding parts and materials can withstand
this temperature.
Avoid contamination of thermistor surface during processing.
Please read
Cautions and warnings
and
Important notes
at the end of this document.
Page 5 of 7
京公网安备 11010802033920号
EEWORLD
