MLRR-3-27-33 Equivalent & Substitute Parts

Part Overview

The MLRR-3-27-33 is a glass body reed switch manufactured by Littelfuse Inc., configured as a SPST-NO (Single Pole Single Throw - Normally Open) device. This through-hole component is designed for applications requiring reliable switching at 700mA AC or 1A DC with a 140V AC switching voltage rating. The part is currently active in production with full inventory availability. Substitute parts are identified when electrical specifications, mechanical compatibility, and regulatory compliance remain equivalent across the allowed parameter range.

Substiute Parts

MLRR-3-27-33

Littelfuse Inc.In Stock: 1721MLRR-3-27-33 Datasheet

Current PartRFQ

MLRR-4-27-33

Littelfuse Inc.In Stock: 2003MLRR-4-27-33 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The MLRR-4-27-33 qualifies as a direct substitute for the MLRR-3-27-33 based on the following equivalence criteria:

Electrical Parameters (Identical):

• Circuit configuration: SPST-NO
• Operate range: 27 ~ 33AT
• Switching current: 700mA (AC), 1A (DC)
• Switching voltage: 140V (AC), 200V (DC)
• Rated power: 20W
• Operating temperature: -40°C ~ 125°C

Mechanical Parameters (Compatible):

• Mounting type: Through Hole
• Termination style: Axial
• Body size: 0.105" Dia x 0.600" L (2.66mm x 15.24mm)

Regulatory & Compliance (Equivalent):

• RoHS3 Compliant
• REACH Unaffected
• Moisture Sensitivity Level: 1 (Unlimited)

The primary difference between these parts is the overall length and switching response time, which do not affect functional substitution within the specified electrical and mechanical constraints.

Parameter Comparison

Engineering Selection Recommendations

Both MLRR-3-27-33 and MLRR-4-27-33 are active production components with ROHS3 compliance and equivalent electrical switching specifications. Selection between these parts is determined by application-specific requirements:

Select MLRR-3-27-33 when:

• Higher DC carry current (1.2A) is required
• Overall length of 2.230" (56.64mm) fits the PCB layout
• Slightly longer switching response time (0.7 ms operate time) is acceptable

Select MLRR-4-27-33 when:

• Compact form factor is required (1.590" overall length)
• Faster switching response (0.6 ms operate time) is beneficial
• DC carry current of 1A meets application requirements

Both parts maintain identical electrical performance for switching operations at 700mA AC / 1A DC and 140V AC / 200V DC ratings. Regulatory compliance and moisture sensitivity levels are equivalent across both options.

Frequently Asked Questions (FAQ)

Q: Can MLRR-4-27-33 directly replace MLRR-3-27-33 in existing designs?

A: Yes, provided the shorter overall length (1.590" vs 2.230") accommodates the PCB layout and the DC carry current requirement does not exceed 1A. All electrical switching parameters are identical.

Q: What is the significance of the operate range specification (27 ~ 33AT)?

A: This specification defines the magnetic field strength (in Ampere-Turns) required to actuate the reed switch. Both parts operate within the same range, ensuring equivalent response to magnetic field stimulation.

Q: Are there differences in reliability or lifespan between these parts?

A: Both parts are manufactured by Littelfuse Inc. with identical circuit configuration, voltage ratings, and operating temperature ranges. No reliability differences are specified in the provided parameters.

Q: What does the 0.4 pF capacitance specification indicate?

A: This represents the parasitic capacitance of the reed switch contacts. Both parts have identical capacitance, ensuring equivalent performance in high-frequency or sensitive signal applications.

Q: Can these parts be used interchangeably in AC and DC applications?

A: Yes. Both parts are rated for 700mA AC switching and 1A DC switching. The MLRR-3-27-33 supports higher DC carry current (1.2A vs 1A), but both meet the specified switching current requirements.

Q: What is the significance of the MSL 1 (Unlimited) moisture sensitivity rating?

A: MSL 1 indicates the component has unlimited shelf life and requires no special moisture control during storage or handling, simplifying inventory management and logistics.