Environmental Characteristics
Operating/Storage Temperature ...................... -40 °C to +85 °C
Maximum Device Surface Temperature
in Tripped State ............................................ 125 °C
Passive Aging .................................................. +85 °C, 1000 hours ...........................................±5 % typical resistance change
Humidity Aging................................................. +85 °C, 85 % R.H. 1000 hours .........................±5 % typical resistance change
Thermal Shock ................................................ -40 °C to +85 °C, 10 times ................................±10 % typical resistance change
Solvent Resistance .......................................... MIL-STD-202, Method 215 ...............................No change
Vibration .......................................................... MIL-STD-883C, Method 2007.1,.......................No change
Condition A
Test Procedures And Requirements For Model MF-RX Series
Test Test Conditions Accept/Reject Criteria
Visual/Mech. .................................................... Verify dimensions and materials .......................Per MF physical description
Resistance ....................................................... In still air @ 23 °C .............................................Rmin ≤ R ≤ Rmax
Time to Trip ...................................................... 5 times Ihold, Vmax, 23 °C ...............................T ≤ max. time to trip (seconds)
Hold Current .................................................... 30 min. at Ihold .................................................No trip
Trip Cycle Life .................................................. Vmax, Imax, 100 cycles ....................................No arcing or burning
Trip Endurance ................................................ Vmax, 48 hours .................................................No arcing or burning
UL File Number ............................................... E174545
TÜV File Number ............................................. R2057213
Electrical Characteristics
Model
V max.
Volts
I max.
Amps
I
hold
I
trip
Initial
Resistance
1 Hour (R
1
)
Post-Trip
Resistance
Max. Time
to Trip
Tripped
Power
Dissipation
Amperes
at 23 °C
Ohms
at 23 °C
Ohms
at 23 °C
Amperes
at 23 °C
Seconds
at 23 °C
Watts
at 23 °C
Hold Trip Min. Max. Max. Typ.
MF-RX110 60 40 1.10 2.20 0.15 0.25 0.38 5.5 8.2 1.50
MF-RX135 60 40 1.35 2.70 0.12 0.19 0.30 6.75 9.6 1.70
MF-RX160 60 40 1.60 3.20 0.09 0.14 0.22 8.0 11.4 1.90
MF-RX185 60 40 1.85 3.70 0.08 0.12 0.19 9.25 12.6 2.10
MF-RX250 60 40 2.50 5.00 0.05 0.08 0.13 12.5 15.6 2.50
MF-RX300 60 40 3.00 6.00 0.04 0.06 0.10 15.0 19.8 2.80
MF-RX375 60 40 3.75 7.50 0.03 0.05 0.08 18.75 24.0 3.20
Features
n Radial Leaded Devices
n Cured, flame retardant epoxy polymer
insulating material meets UL 94V-0
requirements
n Agency recognition:
n RoHS compliant* and halogen free**
MF-RX Series - PTC Resettable Fuses
The MF-RX Series is currently
available, although not recommended
for new designs. The higher voltage
rated MF-RX/72 Series is preferred.
Thermal Derating Chart - I
hold
/ I
trip
(Amps)
Model
Ambient Operating Temperature
-40 ºC -20 ºC 0 ºC 23 ºC 40 ºC 50 ºC 60 ºC 70 ºC 85 ºC
MF-RX110 1.71 / 3.42 1.50 / 3.00 1.31 / 2.62 1.10 / 2.20 0.89 / 1.78 0.79 / 1.58 0.69 / 1.38 0.59 / 1.18 0.44 / 0.88
MF-RX135 2.09 / 4.18 1.84 / 3.68 1.61 / 3.22 1.35 / 2.70 1.09 / 2.18 0.97 / 1.94 0.85 / 1.70 0.73 / 1.46 0.54 / 1.08
MF-RX160 2.48 / 4.96 2.18 / 4.36 1.90 / 3.80 1.60 / 3.20 1.30 / 2.60 1.15 / 2.30 1.01 / 2.02 0.86 / 1.72 0.64 / 1.28
MF-RX185 2.87 / 5.74 2.52 / 5.04 2.20 / 4.40 1.85 / 3.70 1.50 / 3.00 1.33 / 2.66 1.17 / 2.34 1.00 / 2.00 0.74 / 1.48
MF-RX250 3.88 / 7.76 3.40 / 6.80 2.98 / 5.96 2.50 / 5.00 2.03 / 4.06 1.80 / 3.60 1.58 / 3.16 1.35 / 2.70 1.00 / 2.00
MF-RX300 4.65 / 9.30 4.08 / 8.16 3.57 / 7.14 3.00 / 6.00 2.43 / 4.86 2.16 / 4.32 1.89 / 3.78 1.62 / 3.24 1.20 / 2.40
MF-RX375 5.81 / 11.6 5.10 / 10.2 4.46 / 8.92 3.75 / 7.50 3.04 / 6.08 2.70 / 5.40 2.36 / 4.72 2.03 / 4.06 1.50 / 3.00
* RoHS Directive 2002/95/EC Jan. 27, 2003 including annex and RoHS Recast 2011/65/EU June 8, 2011.
** Bourns follows the prevailing definition of “halogen free” in the industry. Bourns considers a product to be “halogen free” if (a) the Bromine (Br) content is 900 ppm or less;
(b) the Chlorine (Cl) content is 900 ppm or less; and (c) the total Bromine (Br) and Chlorine (Cl) content is 1500 ppm or less.
Specifications are subject to change without notice.
The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specific applications.
*RoHS COMPLIANT
LEAD FREE
*RoHS COMPLIANT
&
**HALOGEN FREE
LEAD FREE
VERSIONS ARE
RoHS COMPLIANT*
