B39431B3757U310 Equivalent & Substitute Parts

Part Overview

The B39431B3757U310 is a 434.42MHz Surface Acoustic Wave (SAW) filter manufactured by Qualcomm for RF front-end (RFFE) applications. This component operates as a remote control RF filter with 2dB insertion loss and 120kHz bandwidth in an 8-SMD, No Lead surface mount package. The part is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing system support and new designs requiring this frequency specification.

Substiute Parts

B39431B3757U310

Qualcomm (RF front-end (RFFE) filters)In Stock: 1154B39431B3757U310 Datasheet

Current PartRFQ

B39431B3733H110

Qualcomm (RF front-end (RFFE) filters)In Stock: 1213B39431B3733H110 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the B39431B3757U310 is determined by the following critical parameters:

Primary Matching Criteria:

• Center frequency: 434.42MHz (exact match required for RF filtering application)
• Application: Remote Control RF filtering
• Manufacturer: Qualcomm RFFE filters
• Compliance: ROHS3 Compliant, REACH Unaffected, EAR99 classification

Secondary Compatibility Factors:

• Insertion loss within acceptable operational range (2dB to 2.1dB)
• Surface mount technology with No Lead configuration
• Moisture sensitivity level MSL 1
• Package footprint compatibility with PCB layout constraints

The B39431B3733H110 qualifies as a substitute based on matching center frequency, application domain, manufacturer, and regulatory compliance. Differences in package size (6-SMD vs. 8-SMD), height profile, and insertion loss represent trade-offs that must be evaluated against specific circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

B39431B3733H110 as Primary Substitute:

The B39431B3733H110 is the designated substitute for the obsolete B39431B3757U310 based on identical center frequency (434.42MHz) and matching application domain (Remote Control RF filtering). Both components maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity.

The substitute offers the following advantages:

• Active product status ensures ongoing availability and manufacturing support
• AEC-Q200 automotive qualification rating provides enhanced reliability documentation
• Reduced package footprint (3.00mm x 3.00mm vs. 5.00mm x 5.00mm) and lower profile (1.00mm vs. 1.35mm) enable space-constrained PCB designs
• Tape & Reel packaging supports automated assembly processes

Design Considerations:

The 0.1dB increase in insertion loss (2.1dB vs. 2dB) and transition from 8-SMD to 6-SMD package configuration require PCB layout re-evaluation. The smaller footprint necessitates updated land pattern definitions and assembly fixture modifications. Circuit performance impact from the insertion loss differential must be assessed within the specific remote control RF system architecture.

Frequently Asked Questions (FAQ)

Q: Can B39431B3733H110 directly replace B39431B3757U310 without circuit modifications?

A: Both components operate at 434.42MHz with compatible insertion loss specifications (2dB vs. 2.1dB). However, the package transition from 8-SMD to 6-SMD requires PCB footprint redesign. The reduced physical dimensions (3.00mm x 3.00mm vs. 5.00mm x 5.00mm) and lower profile (1.00mm vs. 1.35mm) necessitate updated land patterns and assembly procedures.

Q: What is the significance of the AEC-Q200 rating on the substitute part?

A: AEC-Q200 is an automotive qualification standard for passive components. This rating on the B39431B3733H110 indicates compliance with automotive reliability and environmental stress testing requirements. The main part does not specify this rating.

Q: Are both parts RoHS compliant?

A: Yes. Both B39431B3757U310 and B39431B3733H110 are ROHS3 compliant and REACH unaffected, meeting current environmental and hazardous substance regulations.

Q: What is the impact of the insertion loss difference?

A: The B39431B3733H110 exhibits 2.1dB insertion loss compared to 2dB for the B39431B3757U310, representing a 0.1dB increase. This differential must be evaluated within the remote control RF system's signal budget and receiver sensitivity specifications.

Q: Why is the main part classified as obsolete?

A: Obsolete status indicates the B39431B3757U310 is no longer manufactured or supported by Qualcomm. The B39431B3733H110, with active product status, represents the current manufacturing alternative for this frequency and application.

Q: Are moisture sensitivity levels identical?

A: Yes. Both components are rated MSL 1 (Unlimited), indicating no moisture sensitivity restrictions for storage, handling, or assembly processes.