• This PDF catalog is downloaded from the website of Murata Manufacturing co., ltd. Therefore, it’s specifications are subject to change or our products in it may be discontinued without advance notice. Please check with our
sales representatives or product engineers before ordering.
• This PDF catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
R01E.pdf
06.1.25
PTC - NTC
for Surface Mounting
Application
!Note
• This PDF catalog is downloaded from the website of Murata Manufacturing co., ltd. Therefore, it’s specifications are subject to change or our products in it may be discontinued without advance notice. Please check with our
sales representatives or product engineers before ordering.
• This PDF catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
R01E.pdf
06.1.25
What is a Thermistor?
Thermally
Sensitive Resistor
Characteristics of Thermistors
Resistance - Temperature Characteristics
Log
R
2xR25
R25
Thermistor
Positive
Temperature
Coefficient
PTC Thermistor
(POSISTOR
r
)
BaTiO
3
+ X
Ceramics
Log
R
R25
25
PTC
Negative
Temperature
Coefficient
Curie
Point
T
NTC Thermistor
Mn-Ni, Mn-Co-Cu,
Mn-Ni + X
Ceramics
NTC
25
T
PRF15/18 Series Chip POSISTORr for Overheat Sensing
PRF15/18 PTC Chip thermistors detect overheating of
Hybrid ICs, Power Transistors, Power Diodes and
Power ICs etc.
1. 0402 and 0603 light weight
+Vcc
R1
PRF
Thermal
Contact
2. High gain simplifies circuit design
3. Free of contact noise and problems
4. Pb free plated terminations.
5. Sturdy construction resists mechanical vibration
and shock.
Example
Fan Motor
Power IC
Thermal
Contact
Comparator
Control IC
R
L
M
R2
R
E
GND
PRF
Vref
PRF15 Series Characteristics
New
Part Number
PRF15BA471QB1RC
PRF15BB471QB1RC
PRF15BC471QB1RC
Characteristics
BA
BB
BC
470ohm
±50%
Resistance
(at +25°C)
Sensing Temp.
(at 4.7k ohm)
125±5°C
115±5°C
105±5°C
Maximum
Voltage
Operating Temp.
-20 to +140°C
32VDC
-20 to +130°C
-20 to +120°C
Dimensions
0.5±0.05
0.1-0.4
1.0±0.05
0.5±0.05
(in mm)
Electrode
Construction
Cross-sectional
PTC
Ceramic
Sn Plating
Nickel Barrier
!Note
• This PDF catalog is downloaded from the website of Murata Manufacturing co., ltd. Therefore, it’s specifications are subject to change or our products in it may be discontinued without advance notice. Please check with our
sales representatives or product engineers before ordering.
• This PDF catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
R01E.pdf
06.1.25
PRF18 Series Characteristics
Part Number
PRF18AS471QB1RB
PRF18AR471QB1RB
PRF18BA471QB1RB
PRF18BB471QB1RB
PRF18BC471QB1RB
PRF18BD471QB1RB
PRF18BE471QB1RB
PRF18BF471QB1RB
PRF18BG471QB1RB
* Also available with tolerance
±3°C
Characteristics
AS
AR
BA
BB
BC
BD
BE
BF
BG
Resistance
(at +25°C)
Sensing Temp. *
(at 4.7k ohm)
145±5°C
135±5°C
125±5°C *
115±5°C *
Maximum
Voltage
Maximum
Current
Operating Temp.
-20 to +160°C
-20 to +150°C
-20 to +140°C
-20 to +130°C
470 ohm
±50%
105±5°C *
95±5°C *
85±5°C *
75±5°C
65±5°C
32VDC
30mA
-20 to +120°C
-20 to +110°C
-20 to +100°C
-20 to + 90°C
-20 to + 80°C
Rating (0603) - Lead Free Terminations Type and UL1434 (except BF, BG types)
New
Part Number
PRF18BA473QB1RB
Characteristics
BA
Resistance
(at +25°C)
470k ohm
±50%
Sensing Temp.
(at 4.7k ohm)
130±5°C
Maximum
Voltage
32VDC
Operating Temp.
-20 to +140°C
Low Current Consumption!
Dimensions
0.8±0.15
0.1-0.6
1.6±0.15
0.8±0.15
(in mm)
Electrode
Construction
Cross-sectional
PTC
Ceramic
Sn Plating
Nickel Barrier
Circuit Examples
Bimetal
POSISTORr
The POSISTORr has the
following advantages over
Bimetal devices.
1. Noise free
PRF
2. No contact problems
3. Low price
Zener Diode
POSISTORr
PRF
-
+
The POSISTORr has the
following additional advantages
over Zener Diodes.
1. Reduced numbers of parts
used in circuits
Mounting Area
Parts
Zener Diode
10x10 = 100mm
2
UPS
Parts
1
Diode
2
Transistor
7
Resistor
1
Op. Amp.
Total
11
POSISTORr
6x6 = 36mm
2
UPS
Parts
1
POSISTORr
1
Transistor
2
Resistor
0
Op. Amp.
Total
4
2. Reduced process costs of
mounting parts on PCBs
3. Reduces occupied space,
helping high density PCB
mounting
!Note
• This PDF catalog is downloaded from the website of Murata Manufacturing co., ltd. Therefore, it’s specifications are subject to change or our products in it may be discontinued without advance notice. Please check with our
sales representatives or product engineers before ordering.
• This PDF catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
R01E.pdf
06.1.25
Markets & Applications of Overheat Sensing
<Set PTC Used>
PRF
PC Server
Power Supply
LCD
AC Adapter
TV Game
Video Camera
Lighting
Power Supply
Car Audio
DC-DC Converter
AC Adapter
AC Adapter
Dimmer
DC-DC Converter
AMP
LCD
Audio
Air Conditioner
DC Brushless Motor
Refrigerator
PPC/Printer
Copy Machine
DC Brushless Motor
DC Brushless Motor
Lamp
AMP
<Function of PRF>
Overheat Sensing of FET
Overheat Sensing of Power Supply
Overheat Sensing for Inverter Module of Backlight
Overheat Sensing of FET
Overheat Sensing of Case
Overheat Sensing of FET
Overheat Sensing of FET
Overheat Sensing of PCB
Overheat Sensing of Power Tr
Overheat Sensing of FET
Overheat Sensing of Power Hybrid IC
Overheat Sensing of Case
Overheat Sensing for Inverter of Backlight
Overheat Sensing of Power Hybrid IC
Overheat Sensing of Power Hybrid IC
Current Limitation & Overheat Sensing of Driver IC
Overheat Sensing of Driver IC
Overheat Sensing of Driver IC
Overheat Sensing of Lamp Starter Circuit
---
---
---
---
---
Temperature Fuse
---
Temperature Fuse
---
---
NTC Thermistor
<Competitive Device>
Temperature Fuse
---
---
---
---
PRG18/21 Series Chip POSISTORr for Overcurrent Prevention
Chip THERMISTORS prevent failure of apparatus due
to excess current.
1. 0603 and 0805 light weight
2. High gain simplifies circuit design
3. Free of contact noise and problems
4. Pb free plated terminations.
5. Sturdy construction resists mechanical
vibration and shock.
Load
PTC
PTC
PRG Series Characteristics
Ratings - Lead Free Terminations
New
Part Number
Resistance
(at +25°C)
0.20 ohm
±20%
4.7 ohm
±20%
6.8 ohm
±20%
15 ohm
±20%
22 ohm
±20%
33 ohm
±20%
47 ohm
±20%
100 ohm
±20%
220 ohm
±20%
470 ohm
±20%
Maximum
Voltage
6VDC
20VDC
20VDC
Maximum
Current
10A
5A
3.5A
1.6A
1.1A
350mA
300mA
Non-operating
Current (at +60°C)
500mA
100mA
80mA
40mA
30mA
25mA
20mA
15mA
10mA
7mA
Operating
Current (at -10°C)
2000mA
400mA
320mA
140mA
110mA
85mA
75mA
55mA
35mA
25mA
PRG21BC0R2MM1RA
PRG21BC4R7MM1RA
PRG21BC6R8MM1RA
PRG21BB150MB1RK
PRG21BB220MB1RK
PRG18BB330MB1RB
PRG18BB470MB1RB
PRG18BB101MB1RB
PRG18BB221MB1RB
PRG18BB471MB1RB
24VDC
200mA
90mA
40mA
!Note
• This PDF catalog is downloaded from the website of Murata Manufacturing co., ltd. Therefore, it’s specifications are subject to change or our products in it may be discontinued without advance notice. Please check with our
sales representatives or product engineers before ordering.
• This PDF catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
R01E.pdf
06.1.25
Dimensions
L
W
T
e
b
PRG18BB
1.6±0.15
0.8±0.15
0.1-0.6
-
PRG21BB
2.0±0.2
1.25±0.2
0.2 min.
0.5 min.
PRG21BC
2.0±0.2
1.25±0.2
0.9±0.2
0.2 min.
0.5 min.
L
W
e
b
e
T
(in mm)
Multilayer Chip POSISTORr for Overcurrent Protection
Electrode Construction Cross-sectional
PTC
Ceramic
PRG21BC Type
Nickel Barrier
Sn Plating
Data here are reference only. Specifications available upon request. Product to be evaluated, confirmed by the user before actual use.
Description here may be revised without notice.
POSISTORr Ideas
From Fuse Resistor
Fuse Resistor
IN
FET
OUT
IN
FET
PRG
OUT
From Current Control Circuit
PRG
IN
OUT
IN
OUT
Limitting
Circuit
Limitting
Circuit
Auto-reset
Simple
Item
POSISTORr
Fuse Resistor
Control Circuit
Chip Resistor
From Chip Resistor
PRG
IN
FET
OUT IN
FET
OUT
Safety
Repeat
Control
Circuit
Control
Circuit
Space
Down Sizing &
Overcurrent Protecting
Cost
Key:
Cross = Bad - Circle = Good - Triangle = Little difference
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