Murata Electronics 7BB-27-4C Equivalent & Substitute Parts

Part Overview

The Murata Electronics 7BB-27-4C is a 4.6 kHz feedback buzzer element with a 27mm diameter form factor and 200 Ohms impedance. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. Finding equivalent substitute parts is necessary for applications requiring continued supply, maintenance, or redesign of legacy systems utilizing this buzzer element.

Substiute Parts

7BB-27-4C

Murata ElectronicsIn Stock: 21427BB-27-4C Datasheet

Current PartRFQ

AB2745BF

PUI Audio, Inc.In Stock: 918AB2745BF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Murata Electronics 7BB-27-4C is determined by the following critical parameters:

• Physical Form Factor: 27mm diameter (1.063" Dia) — maintains mechanical compatibility with existing mounting and enclosure designs
• Functional Type: Feedback buzzer element — ensures acoustic feedback capability is preserved
• Frequency Range: Nominal operating frequency near 4.6 kHz — allows for acceptable audio output characteristics
• Impedance Compatibility: Electrical impedance suitable for driver circuit integration
• Compliance Standards: RoHS3 and REACH compliance — ensures regulatory alignment with modern manufacturing and environmental standards

The substitute part AB2745BF from PUI Audio, Inc. meets these substitution criteria through equivalent physical dimensions, feedback buzzer functionality, and comparable frequency operation within acceptable engineering tolerances.

Parameter Comparison

Engineering Selection Recommendations

The PUI Audio AB2745BF serves as the primary substitute for the Murata Electronics 7BB-27-4C based on the following engineering criteria:

Product Status Alignment: The AB2745BF maintains Active product status, ensuring continued availability and manufacturer support, whereas the 7BB-27-4C is designated "Not For New Designs."

Regulatory Compliance: Both components maintain RoHS3 compliance. The AB2745BF offers the additional advantage of REACH Unaffected status, eliminating potential supply chain restrictions associated with REACH-affected materials in the original part.

Physical Compatibility: Identical 27mm diameter form factor ensures direct mechanical substitution without enclosure or mounting modifications.

Electrical Considerations: The AB2745BF operates at 4.5 kHz versus the original 4.6 kHz, representing a 2.2% frequency deviation within acceptable acoustic tolerance for feedback buzzer applications. The impedance increase from 200 Ohms to 500 Ohms and capacitance reduction from 18000pF to 16000pF require driver circuit verification to ensure proper electrical integration.

Frequently Asked Questions (FAQ)

Q: Can the PUI Audio AB2745BF directly replace the Murata 7BB-27-4C without circuit modifications?

A: Physical form factor compatibility is confirmed. However, the impedance difference (200 Ohms to 500 Ohms) and capacitance variation (18000pF to 16000pF) require driver circuit evaluation. The 4.5 kHz frequency of the substitute versus 4.6 kHz of the original represents a minor acoustic shift suitable for most feedback applications.

Q: What is the significance of the frequency difference between 4.6 kHz and 4.5 kHz?

A: The 0.1 kHz difference represents approximately 2.2% deviation. For feedback buzzer elements, this frequency variance typically remains imperceptible to human hearing and does not compromise functional performance in standard audio feedback applications.

Q: Why is the AB2745BF impedance rated at 500 Ohms compared to the original 200 Ohms?

A: Impedance differences reflect design variations between manufacturers. Circuit driver compatibility must be verified based on the specific driver circuit specifications. The provided maximum input voltage of 20V p-p for the AB2745BF establishes the electrical operating envelope for this substitute.

Q: Does the REACH Unaffected status of the AB2745BF provide an advantage?

A: Yes. The REACH Unaffected classification eliminates potential regulatory restrictions on material sourcing and supply chain continuity, providing greater long-term availability assurance compared to the REACH Affected status of the original part.

Q: Are both components suitable for the same operating temperature range?

A: The AB2745BF specifies an operating temperature range of -20°C to 70°C. The original 7BB-27-4C does not provide operating temperature specifications in the available data. Application temperature requirements must be evaluated against the AB2745BF specifications.