Features
n Surface mount packaging for automated
assembly
n Small footprint size (1210) and low profile
for space-constrained mobile applications
n Ultra-low resistance
n RoHS compliant* and halogen free**
n Agency recognition:
MF-USML Series - Low Ohmic PTC Resettable Fuses
*RoHS Directive 2015/863, Mar 31, 2015 and Annex.
**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.
Users should verify actual device performance in their specific applications.
The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
Electrical Characteristics
Model V max.
Volts
I max.
Amps
Ihold Itrip Resistance Max. Time
To Trip
Tripped
Power
Dissipation
Amperes
at 23 °C
Ohms
at 23 °C
Amperes
at 23 °C
Seconds
at 23 °C
Watts
at 23 °C
Hold Trip RMin. R1Max. Typ.
MF-USML175 6 50 1.75 3.50 0.0060 0.0400 8.00 2.50 0.8
MF-USML190 6 50 1.90 4.90 0.0060 0.0300 9.50 3.00 0.8
MF-USML200 6 50 2.00 4.00 0.0050 0.0300 8.00 3.00 0.8
MF-USML230 6 50 2.30 4.60 0.0045 0.0240 8.00 3.50 0.8
MF-USML250 6 50 2.50 5.00 0.0045 0.0220 8.00 3.50 0.8
MF-USML270 6 50 2.70 5.40 0.0040 0.0200 8.00 4.00 0.8
MF-USML300 6 50 3.00 6.00 0.0040 0.0180 8.00 4.00 0.8
MF-USML350 6 50 3.50 7.00 0.0030 0.0180 17.50 2.00 0.8
MF-USML380 6 50 3.80 8.00 0.0020 0.0160 19.00 2.00 0.8
MF-USML400 6 50 4.00 8.00 0.0015 0.0155 20.00 2.00 0.8
MF-USML450 6 50 4.50 9.00 0.0010 0.0150 22.50 2.00 0.8
MF-USML500 6 50 5.00 10.00 0.0010 0.0145 25.00 2.00 0.8
MF-USML600 6 50 6.00 12.00 0.0010 0.0140 30.00 2.00 0.8
MF-USML650 6 50 6.50 13.00 0.0010 0.0140 32.50 2.00 0.8
MF-USML700 6 50 7.00 14.00 0.0010 0.0135 35.00 2.00 0.8
Environmental Characteristics
Operating Temperature ......................................... -40 °C to +85 °C
Storage Condition
Before Opening ................................................ +40 °C max. / 70 % RH max.
After Opening.................................................... +40 °C max. / 10 % RH max.
Floor Condition After Opening .............................. Consumption within 4 weeks at floor condition +30 °C max. / 60 % RH max.
Passive Aging ....................................................... +85 °C, 1000 hours ............................................... ±10 % typical resistance change
Humidity Aging...................................................... +85 °C, 85 % R.H. 100 hours ............................... ±15 % typical resistance change
Thermal Shock ..................................................... +85 °C to -40 °C, 20 times .................................... ±30 % typical resistance change
Solvent Resistance ............................................... MIL-STD-202, Method 215 ................................... No change
Vibration ............................................................... MIL-STD-883C, Method 2007.1, ........................... No change
Condition A
Moisture Sensitivity Level (MSL) .......................... See Note
ESD Classication - HBM ..................................... Class 6
Test Procedures And Requirements
Test Test Conditions Accept/Reject Criteria
Visual/Mech. ......................................................... Verify dimensions and materials ........................... Per MF physical description
Resistance ............................................................ In still air @ 23 °C ................................................. Rmin R R1max
Time to Trip ........................................................... At specied current, 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
Solderability .......................................................... 245 °C ± 5 °C, 5 seconds .................................... 95 % min. coverage
UL File Number .................................................... E174545
TÜV Certicate Number ....................................... R 50302873
WARNING Cancer and Reproductive Harm
www.P65Warnings.ca.gov
This MF-USML series is currently
available, although not recommended
for new designs. The enhanced
MF-USML/X Series is recommended for new
designs.
Specifications are subject to change without notice.
Users should verify actual device performance in their specific applications.
The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
MF-USML Series - Low Ohmic PTC Resettable Fuses
Product Dimensions
DIMENSIONS: MM
(INCHES)
Model A B C D E
Min. Max. Min. Max. Min. Max. Min. Min. Max.
MF-USML175
3.00
(0.118)
3.43
(0.135)
2.35
(0.093)
2.80
(0.110)
0.30
(0.012)
0.60
(0.024)
0.25
(0.010)
0.05
(0.002)
0.45
(0.018)
MF-USML190
MF-USML200
MF-USML230
MF-USML250
MF-USML270
MF-USML300
MF-USML350
MF-USML380
MF-USML400
MF-USML450
3.00
(0.118)
3.43
(0.135)
2.35
(0.093)
2.80
(0.110)
0.60
(0.024)
1.20
(0.047)
0.25
(0.010)
0.05
(0.002)
0.45
(0.018)
MF-USML500
MF-USML600
MF-USML650
MF-USML700
MF-USML175~MF-USML400 = 5000 pcs. per reel
MF-USML450~MF-USML700 = 3500 pcs. per reel
Terminal material:
ENIG-plated terminals
Thermal Derating Table - Ihold (Amps)
Model
Ambient Operating Temperature
-40 °C -20 °C 0 °C 23 °C 40 °C 50 °C 60 °C 70 °C 85 °C
MF-USML175 2.57 2.33 2.07 1.75 1.49 1.34 1.24 1.00 0.88
MF-USML190 2.80 2.55 2.25 1.90 1.60 1.46 1.35 1.09 0.95
MF-USML200 2.94 2.65 2.35 2.00 1.70 1.53 1.42 1.14 1.00
MF-USML230 3.40 3.17 2.74 2.30 1.94 1.72 1.60 1.30 1.15
MF-USML250 3.70 3.35 2.95 2.50 2.10 1.90 1.75 1.40 1.25
MF-USML270 3.98 3.60 3.18 2.70 2.28 2.03 1.90 1.52 1.35
MF-USML300 4.41 3.99 3.54 3.00 2.55 2.30 2.13 1.71 1.50
MF-USML350 5.10 4.65 4.13 3.50 2.98 2.65 2.50 2.00 1.75
MF-USML380 5.59 5.05 4.48 3.80 3.23 2.95 2.70 2.17 1.90
MF-USML400 5.80 5.25 4.70 4.00 3.40 3.10 2.80 2.28 2.00
MF-USML450 6.30 5.65 4.95 4.50 3.83 3.40 2.95 2.50 2.05
MF-USML500 7.00 6.25 5.50 5.00 4.25 3.75 3.25 2.75 2.25
MF-USML600 8.40 7.50 6.60 6.00 5.10 4.50 3.90 3.30 2.65
MF-USML650 9.10 8.15 7.15 6.50 5.50 4.90 4.25 3.60 2.85
MF-USML700 9.80 8.75 7.70 7.00 5.95 5.25 4.55 3.85 3.05
Recommended Pad Layout
2.5 ± 0.1
(.098 ± .004)
2.0 ± 0.1
(.079 ± .004)
1.0 ± 0.05
(.039 ± .002)
1.0 ± 0.05
(.039 ± .002)
Bottom View
D E
A
B
C
Top View Side View
Packaging Specications
Applications
n Thermal protection for Li-ion and polymer
battery packs
n Game consoles
n PC motherboards
n USB port protection - USB 2.0, 3.0 & OTG
n Mobile phones
n Digital cameras
Specifications are subject to change without notice.
Users should verify actual device performance in their specific applications.
The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
MF-USML Series - Low Ohmic PTC Resettable Fuses
How to Order
MF - USML 175 - 2
Multifuse® Product
Designator
Series
USML = 1210 Low-Ohmic
Surface Mount Component
Hold Current, Ihold
175 - 700 (1.75 - 7.00 Amps)
Packaging
Packaged per EIA 481
-2 = Tape and Reel
Typical Part Marking
Represents total content. Layout may vary.
MF-USML SERIES, REV. J, 11/19
PART IDENTIFICATION:
MF-USML175 = U17
MF-USML190 = U19
MF-USML200 = U20
MF-USML230 = U23
MF-USML250 = U25
MF-USML270 = U27
MF-USML300 = U30
MF-USML350 = U35
MF-USML380 = U38
MF-USML400 = U40
MF-USML450 = U45
MF-USML500 = U50
MF-USML600 = U60
MF-USML650 = U65
MF-USML700 = U70
MANUFACTURING DATE CODE IS
LOCATED ON PACKING LABEL.
U30
Asia-Pacic:
Tel: +886-2 2562-4117
Email: asiacus@bourns.com
Europe:
Tel: +36 88 885 877
Email: eurocus@bourns.com
The Americas:
Tel: +1-951 781-5500
Email: americus@bourns.com
www.bourns.com
Solder Reow Recommendations
Notes:
MF-USML models cannot be wave soldered or hand
soldered. Please contact Bourns for soldering
recommendations.
All temperatures refer to topside of the package, measured
on the package body surface.
If reflow temperatures exceed the recommended prole,
devices may not meet the published specications.
Compatible with Pb and Pb-free solder reflow proles.
Excess solder may cause a short circuit, especially during
hand soldering. Please refer to the Multifuse® Polymer PTC
Soldering Recommendation guidelines.
Temperature of Lead/Pad Junction
Process Materials Temperature Time
Description Interval
1. Apply solder paste to Sn 96.5 / Ag 3.0 / Cu 0.5 Room temperature
test board (8 - 10 mil thick) Alloy water soluble or no
clean solder paste
(see note 1)
single sided epoxy glass
(G10) (UL approved)
PC board approx. 4x4x.06 in.
2. Place test units onto board 6 units/board
3. Ramp up Convection oven (see note 2) 2.5 °C ± 0.5 °/sec.
4. Preheat (TS.ces 03 ± 09C° 091 ot C° 051)
5. Time above liquidus (TL.ces 09-06C° 022)
6. Peak temperature (TP° 5-/° 0+ C° 052)
10-20 sec. within
5 °C of peak
.ces/C° 5.0 ± C° 3erutarepmet mooRnwod pmaR.7
(see note 2)
8. Cleaning water clean profile High pressure deionized 72 °F to 160 °F As required
water 65 PSI max. (22 °C to 71 °C)
Inspect solder joint to determine if solder joint is
acceptable (i.e. exhibits wetting of joint’s surface).
Use the following criteria (ref. acceptability of printed
board assemblies, IPC-A-610):
A) Acceptable (see Figure 1)
(1) The solder connection wetting angle (solder to
component and solder to PCB termination)
does not exceed 90 °.
(2) Solder balls that do not violate minimum
electrical clearances and are attached
(soldered) to a metal surface.
B) Unacceptable (see Figure 2)
(1) Solder connection wetting angle exceeding
90 °.
(2) Incomplete reflow of solder paste.
(3) Dewetting.
If unacceptable, determine cause and correct prior to
next run.
NOTES:
1. Water soluble solder paste only above 100K.
2. Refer to ref. temperature profile. Temperature at
lead/pad junction with “K” type thermocouple.
3. Units that are board mounted for environmental
testing must see a peak temperature in the reflow
zone, as specified. This is to ensure that all test
units will see “worst case conditions”.
4. Ramp down rate to be measured from 245 °C to
150 °C.
5. Process Description 8 does not apply to open
frame trimmers.
(Derived using 6-zone Convection Oven)
TP
TP
tp
ts
TTO
RAMP-UP L
TL
tL
T MAX.
S
T MIN.
25
PREHEAT
S
Temperature
Time
CRITICAL ZONE
RAMP-DOWN
t 25 °C TO PEAK
Prole Feature Pb-Free Assembly
Average Ramp-Up Rate (Tsmax to Tp)3 °C / second max.
PREHEAT:
Temperature Min. (Tsmin)
Temperature Max. (Tsmax)
Time (Tsmin to Tsmax) (ts)
150 °C
200 °C
60~180 seconds
TIME MAINTAINED ABOVE:
Temperature (TL)
Time (tL)
217 °C
60~150 seconds
Peak Temperature (Tp) 260 °C
Time within 5 °C of Actual Peak Temperature (tp)20~40 seconds
Ramp-Down Rate 6 °C / second max.
Time 25 °C to Peak Temperature 8 minutes max.
MF-USML Series
Tape Dimensions per EIA 481
W 12.0 ± 0.3
(0.472 ± 0.012)
P0 4.0 ± 0.1
(0.157 ± 0.004)
P1 4.0 ± 0.1
(0.157 ± 0.004)
P2 2.0 ± 0.05
(0.079 ± 0.002)
A0 2.9 ± 0.10
(0.114 ± 0.004)
B0 3.50 ± 0.10
(0.138 ± 0.004)
B1 max. 4.5
(0.177)
D0 1.5 + 0.1/-0.0
(0.059 + 0.004/-0)
F 5.5 ± 0.05
(0.216 + 0.002)
E1 1.75 ± 0.10
(0.069 ± 0.004)
E2 typ. 10.25
(0.404)
T max. 0.6
(0.024)
T1 max. 0.1
(0.004)
K0 (MF-USML175~MF-USML400) 0.65 ± 0.10
(0.026 ± 0.004)
K0 (MF-USML450~MF-USML700) 1.10 ± 0.10
(0.043 ± 0.004)
Leader min. 390
(15.35)
Trailer min. 160
(6.30)
Reel Dimensions
A max. 185
(7.283)
N min. 50
(1.97)
W1 12.4 + 1/-0
(0.488 + 0.039/-0)
W2 max. 15.4
(0.606)
MF-USML Series - Low Ohmic PTC Resettable Fuses
Specifications are subject to change without notice.
Users should verify actual device performance in their specific applications.
The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
B1
N(HUB DIA.)
(MEASURED
AT HUB)
A
T
COVER
TAPE
K0
T1A0
W2
(MEASURED
AT HUB)
W
1
P1
B0
F
D0P2
P
0
E2
E1
W
DIMENSIONS: MM
(INCHES)
3312 - 2 mm SMD Trimming Potentiometer
Application Notice
MFAN 12/18
Specifications are subject to change without notice.
Users should verify actual device performance in their specific applications.
The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
Bourns® Multifuse® PPTC Resettable Fuses
Users are responsible for independent and adequate evaluation of Bourns® Multifuse® Polymer PTC devices in the user’s
application, including the PPTC device characteristics stated in the applicable data sheet.
Polymer PTC devices must not be allowed to operate beyond their stated maximum ratings. Operation in excess of such
maximum ratings could result in damage to the PTC device and possibly lead to electrical arcing and/or re. Circuits with
inductance may generate a voltage above the rated voltage of the polymer PTC device and should be thoroughly evaluated
within the user’s application during the PTC selection and qualication process.
Polymer PTC devices are intended to protect against adverse effects of temporary overcurrent or overtemperature
conditions up to rated limits and are not intended to serve as protective devices where overcurrent or overvoltage conditions
are expected to be repetitive or prolonged.
In normal operation, polymer PTC devices experience thermal expansion under fault conditions. Thus, a polymer PTC
device must be protected against mechanical stress, and must be given adequate clearance within the user’s application to
accommodate such thermal expansion. Rigid potting materials or xed housings or coverings that do not provide adequate
clearance should be thoroughly examined and tested by the user, as they may result in the malfunction of polymer PTC
devices if the thermal expansion is inhibited.
Exposure to lubricants, silicon-based oils, solvents, gels, electrolytes, acids, and other related or similar materials may
adversely affect the performance of polymer PTC devices.
Aggressive solvents may adversely affect the performance of polymer PTC devices. Conformal coating, encapsulating,
potting, molding, and sealing materials may contain aggressive solvents including but not limited to xylene and toluene,
which are known to cause adverse effects on the performance of polymer PTCs. Such aggressive solvents must be
thoroughly cured or baked to ensure their complete removal from polymer PTCs to minimize the possible adverse effect
on the device.
Recommended storage conditions should be followed at all times. Such conditions can be found on the applicable data
sheet and on the Multifuse® Polymer PTC Moisture/Reow Sensitivity Classication (MSL) note:
https://www.bourns.com/docs/RoHS-MSL/msl_mf.pdf
Legal Disclaimer Notice
This legal disclaimer applies to purchasers and users of Bourns® products manufactured by or on behalf of Bourns, Inc. and its
afliates (collectively, “Bourns”).
Unless otherwise expressly indicated in writing, Bourns® products and data sheets relating thereto are subject to change
without notice. Users should check for and obtain the latest relevant information and verify that such information is current and
complete before placing orders for Bourns® products.
The characteristics and parameters of a Bourns® product set forth in its data sheet are based on laboratory conditions, and
statements regarding the suitability of products for certain types of applications are based on Bourns’ knowledge of typical
requirements in generic applications. The characteristics and parameters of a Bourns® product in a user application may vary
from the data sheet characteristics and parameters due to (i) the combination of the Bourns® product with other components
in the user’s application, or (ii) the environment of the user application itself. The characteristics and parameters of a Bourns®
product also can and do vary in different applications and actual performance may vary over time. Users should always verify
the actual performance of the Bourns® product in their specic devices and applications, and make their own independent
judgments regarding the amount of additional test margin to design into their device or application to compensate for
differences between laboratory and real world conditions.
Unless Bourns has explicitly designated an individual Bourns® product as meeting the requirements of a particular industry
standard (e.g., ISO/TS 16949) or a particular qualication (e.g., UL listed or recognized), Bourns is not responsible for any
failure of an individual Bourns® product to meet the requirements of such industry standard or particular qualication. Users of
Bourns® products are responsible for ensuring compliance with safety-related requirements and standards applicable to their
devices or applications.
Bourns® products are not recommended, authorized or intended for use in nuclear, lifesaving, life-critical or life-sustaining ap-
plications, nor in any other applications where failure or malfunction may result in personal injury, death, or severe property or
environmental damage. Unless expressly and specically approved in writing by two authorized Bourns representatives on a
case-by-case basis, use of any Bourns® products in such unauthorized applications might not be safe and thus is at the user’s
sole risk. Life-critical applications include devices identied by the U.S. Food and Drug Administration as Class III devices and
generally equivalent classications outside of the United States.
Bourns expressly identies those Bourns® standard products that are suitable for use in automotive applications on such
products’ data sheets in the section entitled “Applications.” Unless expressly and specically approved in writing by two
authorized Bourns representatives on a case-by-case basis, use of any other Bourns® standard products in an automotive
application might not be safe and thus is not recommended, authorized or intended and is at the user’s sole risk. If Bourns
expressly identies a sub-category of automotive application in the data sheet for its standard products (such as infotainment
or lighting), such identication means that Bourns has reviewed its standard product and has determined that if such Bourns®
standard product is considered for potential use in automotive applications, it should only be used in such sub-category of
automotive applications. Any reference to Bourns® standard product in the data sheet as compliant with the AEC-Q standard
or “automotive grade” does not by itself mean that Bourns has approved such product for use in an automotive application.
Bourns® standard products are not tested to comply with United States Federal Aviation Administration standards generally
or any other generally equivalent governmental organization standard applicable to products designed or manufactured for
use in aircraft or space applications. Bourns expressly identies Bourns® standard products that are suitable for use in aircraft
or space applications on such products’ data sheets in the section entitled “Applications.” Unless expressly and specically
approved in writing by two authorized Bourns representatives on a case-by-case basis, use of any other Bourns® standard
product in an aircraft or space application might not be safe and thus is not recommended, authorized or intended and is at the
user’s sole risk.
The use and level of testing applicable to Bourns® custom products shall be negotiated on a case-by-case basis by Bourns and
the user for which such Bourns® custom products are specially designed. Absent a written agreement between Bourns and the
user regarding the use and level of such testing, the above provisions applicable to Bourns® standard products shall also apply
to such Bourns® custom products.
Users shall not sell, transfer, export or re-export any Bourns® products or technology for use in activities which involve the
design, development, production, use or stockpiling of nuclear, chemical or biological weapons or missiles, nor shall they use
Bourns® products or technology in any facility which engages in activities relating to such devices. The foregoing restrictions
apply to all uses and applications that violate national or international prohibitions, including embargos or international
regulations. Further, Bourns® products and Bourns technology and technical data may not under any circumstance be
exported or re-exported to countries subject to international sanctions or embargoes. Bourns® products may not, without prior
authorization from Bourns and/or the U.S. Government, be resold, transferred, or re-exported to any party not eligible
to receive U.S. commodities, software, and technical data.
To the maximum extent permitted by applicable law, Bourns disclaims (i) any and all liability for special, punitive, consequential,
incidental or indirect damages or lost revenues or lost prots, and (ii) any and all implied warranties, including implied warranties
of tness for particular purpose, non-infringement and merchantability.
For your convenience, copies of this Legal Disclaimer Notice with German, Spanish, Japanese, Traditional Chinese and Simplied Chinese
bilingual versions are available at:
Web Page: http://www.bourns.com/legal/disclaimers-terms-and-policies
PDF: http://www.bourns.com/docs/Legal/disclaimer.pdf
C1753 05/17/18R