MICROSMD050-2 Equivalent & Substitute Parts

Part Overview

The MICROSMD050-2 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., rated for 13.2V maximum voltage and 500 mA hold current. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement. The part is designed for surface mount applications in the 1210 (3225 Metric) package format with a concave profile. Identifying compatible alternatives ensures design continuity and supply chain flexibility for applications requiring polymeric PTC resettable fuse protection.

Key Parameters

Parameter	Value
Voltage - Max	13.2V
Current - Hold (Ih) (Max)	500 mA
Current - Trip (It)	1 A
Current - Max	40 A
Mounting Type	Surface Mount
Package / Case	1210 (3225 Metric), Concave
Operating Temperature	-40°C ~ 85°C
Type	Polymeric

Substitute Part Grouping Explanation

Substitution eligibility for the MICROSMD050-2 is determined by strict alignment with the following electrical and mechanical parameters:

Voltage rating: 13.2V maximum
Hold current: 500 mA maximum
Trip current: 1 A
Maximum current: 40 A
Package: 1210 (3225 Metric), Concave
Mounting: Surface Mount
Operating temperature range: -40°C to 85°C
Component type: Polymeric PTC resettable fuse

Substitute parts must match all critical electrical parameters and physical package specifications. Variations in secondary parameters such as initial resistance, post-trip resistance, time to trip, and thickness are acceptable within engineering tolerances provided the primary electrical and mechanical specifications remain equivalent.

Parameter Comparison

Parameter	MICROSMD050-2 (Main)	MICROSMD050F-2 (Littelfuse)	MF-USMF050-2 (Bourns)
Manufacturer	Littelfuse Inc.	Littelfuse Inc.	Bourns Inc.
Voltage - Max	13.2V	13.2V	13.2V
Current - Hold (Ih) (Max)	500 mA	500 mA	500 mA
Current - Trip (It)	1 A	1 A	1 A
Current - Max	40 A	40 A	40 A
Time to Trip	50 ms	50 ms	100 ms
Resistance - Initial (Ri) (Min)	250 mOhms	250 mOhms	180 mOhms
Resistance - Post Trip (R1) (Max)	900 mOhms	900 mOhms	900 mOhms
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C
Mounting Type	Surface Mount	Surface Mount	Surface Mount
Package / Case	1210 (3225 Metric), Concave	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 0.102" W (3.22mm x 2.58mm)	0.127" L x 0.102" W (3.22mm x 2.58mm)
Thickness (Max)	0.024" (0.62mm)	0.024" (0.62mm)	0.033" (0.85mm)
Product Status	Obsolete	Active	Active
RoHS Status	RoHS non-compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	CSA, TUV, UL	CSA, TUV, UL	cURus, TUV

Engineering Selection Recommendations

MICROSMD050F-2 (Littelfuse Inc.) is the primary parametric equivalent. This part maintains identical electrical specifications and package dimensions while offering active product status and ROHS3 compliance. The MICROSMD050F-2 is supplied in Tape & Reel packaging with 16,000 units in stock.

MF-USMF050-2 (Bourns Inc.) is a direct manufacturer alternative with equivalent electrical performance. This part differs in time to trip (100 ms versus 50 ms), initial resistance (180 mOhms versus 250 mOhms), and maximum thickness (0.033" versus 0.024"). The MF-USMF050-2 carries AEC-Q200 automotive qualification and cURus/TUV approvals. Physical thickness variation requires PCB layout verification for space-constrained applications. This part is available in Tape & Reel format with 30,200 units in stock.

Both substitute parts are ROHS3 compliant and carry active product status, addressing the obsolescence of the original MICROSMD050-2.

Frequently Asked Questions (FAQ)

Q: Can MICROSMD050F-2 be used as a direct replacement for MICROSMD050-2?

A: Yes. The MICROSMD050F-2 maintains identical electrical parameters (13.2V, 500 mA hold current, 1 A trip current) and package specifications (1210 Concave). The primary difference is product status: MICROSMD050F-2 is active and ROHS3 compliant, while MICROSMD050-2 is obsolete and RoHS non-compliant.

Q: What is the difference between MICROSMD050F-2 and MF-USMF050-2?

A: Both parts meet the core electrical requirements. Key differences include: time to trip (50 ms for MICROSMD050F-2 versus 100 ms for MF-USMF050-2), initial resistance (250 mOhms versus 180 mOhms), maximum thickness (0.024" versus 0.033"), and manufacturer (Littelfuse versus Bourns). The MF-USMF050-2 includes AEC-Q200 automotive qualification.

Q: Does the thickness difference between MICROSMD050F-2 and MF-USMF050-2 affect PCB compatibility?

A: The MF-USMF050-2 has a maximum thickness of 0.033" compared to 0.024" for MICROSMD050F-2. This 0.009" difference requires verification against PCB layout constraints, particularly in space-limited applications or where component stacking is involved.

Q: Are both substitute parts available in the same packaging format?

A: Yes. Both MICROSMD050F-2 and MF-USMF050-2 are supplied in Tape & Reel (TR) format, suitable for automated assembly processes.

Q: What certifications apply to the substitute parts?

A: MICROSMD050F-2 carries CSA, TUV, and UL approvals. MF-USMF050-2 carries cURus and TUV approvals, plus AEC-Q200 automotive qualification. Both are ROHS3 compliant.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message