MF-USML175-2 PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-USML175-2 is a Polymeric PTC Resettable Fuse manufactured by Bourns Inc., rated for 6V at 1.75A hold current in a 1210 (3225 Metric) surface mount package. This component is classified as Obsolete, making identification of suitable substitutes necessary for ongoing design support and procurement continuity. The part is ROHS3 compliant and carries cURus and TUV approvals.

Key Parameters

Parameter	Value
Voltage - Max	6V
Current - Hold (Ih) (Max)	1.75 A
Current - Trip (It)	4.6 A
Current - Max	50 A
Resistance - Initial (Ri) (Min)	6 mOhms
Package / Case	1210 (3225 Metric), Concave
Mounting Type	Surface Mount
Operating Temperature	-40°C ~ 85°C
RoHS Status	ROHS3 Compliant
Approval Agency	cURus, TUV

Substitute Part Grouping Explanation

Substitution eligibility for the MF-USML175-2 is determined by the following critical parameters:

Voltage rating of 6V maximum
Current hold (Ih) rating of 1.75A maximum
Current trip (It) rating of 4.6A
Surface mount 1210 (3225 Metric) package configuration
Polymeric PTC type construction
Operating temperature range of -40°C to 85°C
ROHS3 compliance and cURus/TUV approvals

The substitute part MF-USML175/6-2 meets all these criteria, with variations only in time to trip (800 ms vs. 2.5 s), post-trip resistance (50 mOhms vs. 40 mOhms maximum), and thickness (0.031" vs. 0.024" maximum). These variations remain within acceptable tolerance for functional equivalence in the specified application category.

Parameter Comparison

Parameter	MF-USML175-2	MF-USML175/6-2
Manufacturer	Bourns Inc.	Bourns Inc.
Type	Polymeric	Polymeric
Voltage - Max	6V	6V
Current - Hold (Ih) (Max)	1.75 A	1.75 A
Current - Trip (It)	4.6 A	4.6 A
Current - Max	50 A	50 A
Resistance - Initial (Ri) (Min)	6 mOhms	6 mOhms
Resistance - Post Trip (R1) (Max)	40 mOhms	50 mOhms
Time to Trip	2.5 s	800 ms
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C
Mounting Type	Surface Mount	Surface Mount
Package / Case	1210 (3225 Metric), Concave	1210 (3225 Metric), Concave
Size / Dimension	0.127" L x 0.102" W (3.22mm x 2.58mm)	0.127" L x 0.101" W (3.22mm x 2.58mm)
Thickness (Max)	0.024" (0.60mm)	0.031" (0.80mm)
Approval Agency	cURus, TUV	cURus, TUV
RoHS Status	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	2A (4 Weeks)	2A (4 Weeks)
Product Status	Obsolete	Active

Engineering Selection Recommendations

The MF-USML175/6-2 is the direct substitute for the obsolete MF-USML175-2. Both parts carry identical regulatory approvals (cURus, TUV) and ROHS3 compliance status. The substitute part is currently in Active product status, ensuring long-term availability and supply chain continuity.

The MF-USML175/6-2 is available in Tape & Reel (TR) packaging, whereas the original part number does not specify packaging format. Both parts maintain the same electrical ratings for voltage, hold current, trip current, and initial resistance. The substitute exhibits faster trip response (800 ms vs. 2.5 s) and slightly higher post-trip resistance (50 mOhms vs. 40 mOhms maximum), along with marginally increased thickness (0.031" vs. 0.024" maximum). These parameter variations are within the functional tolerance of the 1210 surface mount package class and do not compromise interchangeability for standard circuit protection applications.

Frequently Asked Questions (FAQ)

Q: Can MF-USML175/6-2 be used as a direct replacement for MF-USML175-2?

A: Yes. Both parts share identical voltage (6V), hold current (1.75A), trip current (4.6A), and package configuration (1210 Concave). The substitute is electrically and mechanically compatible for the same application requirements.

Q: What is the significance of the faster trip time in MF-USML175/6-2?

A: The substitute part trips at 800 ms compared to 2.5 s in the original. This represents faster fault response, which may be advantageous in applications requiring quicker circuit protection. Verify that your circuit design tolerates this faster response characteristic.

Q: Are there packaging differences between these parts?

A: The original MF-USML175-2 does not specify packaging format. The substitute MF-USML175/6-2 is supplied in Tape & Reel (TR) format, which is standard for high-volume surface mount assembly. Both parts use the same 1210 (3225 Metric) package footprint.

Q: Does the thickness difference affect PCB assembly?

A: The substitute is 0.031" (0.80mm) thick versus 0.024" (0.60mm) for the original. This 0.007" difference is minimal and does not typically impact PCB layout or assembly processes for standard 1210 components. Confirm clearance in your specific board design if height-constrained applications are involved.

Q: Are both parts ROHS3 compliant?

A: Yes. Both MF-USML175-2 and MF-USML175/6-2 are ROHS3 compliant with identical cURus and TUV approvals, meeting the same regulatory requirements.

Q: Why is the original part marked as Obsolete?

A: The MF-USML175-2 is classified as Obsolete by the manufacturer. The MF-USML175/6-2 is the Active replacement, ensuring continued availability and support for new designs and production runs.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message