7B-18.432MBBK-T Equivalent & Substitute Parts

Part Overview

The 7B-18.432MBBK-T is an 18.432 MHz surface mount crystal oscillator manufactured by TXC CORPORATION. This component operates at a fundamental frequency with ±50ppm stability and 20pF load capacitance in a 4-SMD, No Lead package measuring 5.00mm × 3.20mm. The part is currently classified as obsolete, necessitating identification of active equivalent and substitute components for ongoing design support and procurement continuity.

Substiute Parts

7B-18.432MBBK-T

TXC CORPORATIONIn Stock: 8697B-18.432MBBK-T Datasheet

Current PartRFQ

7M-18.432MBBK-T

TXC CORPORATIONIn Stock: 7657M-18.432MBBK-T Datasheet

SimilarRFQ

ECS-184-20-33-TR

ECS Inc.In Stock: 1716ECS-184-20-33-TR Datasheet

SimilarRFQ

7B-18.432MBBK-T

FTSIn Stock: 18837B-18.432MBBK-T Datasheet

Parametric EquivalentRFQ

QT532S-18.432MBBK-T

QSTIn Stock: 2141QT532S-18.432MBBK-T Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 7B-18.432MBBK-T is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• Frequency: 18.432 MHz (exact match required)
• Frequency Stability: ±50ppm (exact match required)
• Load Capacitance: 20pF (exact match required)
• Operating Mode: Fundamental (exact match required)
• Operating Temperature Range: -20°C to 70°C (exact match required)
• Package / Case: 4-SMD, No Lead (exact match required)
• Mounting Type: Surface Mount (exact match required)

Allowable Variation Parameters:

• ESR (Equivalent Series Resistance): 40 Ohms or 80 Ohms (within acceptable operating range)
• Physical Dimensions: 5.00mm × 3.20mm or 3.20mm × 2.50mm (both accommodate 4-SMD, No Lead package standard)
• Height - Seated (Max): 1.05mm or 0.80mm (both within surface mount assembly tolerances)

Substitute parts are grouped into two categories: Direct Parametric Equivalents (matching ESR and dimensions) and Functional Equivalents (matching all critical electrical parameters with allowable mechanical variations).

Parameter Comparison

Engineering Selection Recommendations

Direct Parametric Equivalents (Preferred for Pin-Compatible Replacement):

The 7B-18.432MBBK-T manufactured by FTS and the QT532S-18.432MBBK-T manufactured by QST are direct parametric equivalents to the obsolete TXC CORPORATION 7B-18.432MBBK-T. These parts match all electrical specifications (40 Ohms ESR) and physical dimensions (5.00mm × 3.20mm, 1.05mm height). Both are currently in active production status with RoHS compliance certification. FTS part carries 1,813 units in stock inventory, while QST part carries 2,038 units. These components require no circuit redesign and support direct board-level substitution.

Functional Equivalents (Alternative for System-Level Integration):

The 7M-18.432MBBK-T manufactured by TXC CORPORATION and the ECS-184-20-33-TR manufactured by ECS Inc. are functional equivalents matching all critical electrical parameters (18.432 MHz, ±50ppm stability, 20pF load capacitance, fundamental mode operation, -20°C to 70°C temperature range). These parts feature 80 Ohms ESR and reduced physical dimensions (3.20mm × 2.50mm, 0.80mm height). Both are active production components with RoHS compliance. The 7M-18.432MBBK-T carries 698 units in stock, while ECS-184-20-33-TR carries 1,619 units. These components are suitable for new designs or redesigns where the smaller footprint provides board space optimization benefits.

Compliance Status:

All substitute parts maintain RoHS compliance and MSL 1 (Unlimited) moisture sensitivity rating, ensuring compatibility with standard surface mount assembly processes and storage requirements.

Frequently Asked Questions (FAQ)

Q: Can the 7M-18.432MBBK-T replace the obsolete 7B-18.432MBBK-T in existing designs?

A: The 7M-18.432MBBK-T matches all critical electrical parameters but differs in physical dimensions (3.20mm × 2.50mm versus 5.00mm × 3.20mm) and ESR (80 Ohms versus 40 Ohms). Circuit redesign is required to accommodate the smaller footprint. ESR variation may affect circuit performance in applications with tight impedance matching requirements.

Q: What is the difference between the 40 Ohms and 80 Ohms ESR variants?

A: ESR (Equivalent Series Resistance) affects crystal oscillator power consumption and circuit stability. The 40 Ohms variant (7B-18.432MBBK-T by TXC, FTS, and QST) provides lower resistance, while the 80 Ohms variant (7M-18.432MBBK-T and ECS-184-20-33-TR) provides higher resistance. Selection depends on circuit design specifications and oscillator drive level requirements.

Q: Are the FTS and QST parts true equivalents to the TXC 7B-18.432MBBK-T?

A: Yes. The FTS 7B-18.432MBBK-T and QST QT532S-18.432MBBK-T match all electrical specifications and physical dimensions of the obsolete TXC 7B-18.432MBBK-T. Both are active production components suitable for direct substitution without circuit modification.

Q: What packaging formats are available for these substitute parts?

A: The TXC 7B-18.432MBBK-T (obsolete) was supplied in Cut Tape (CT) and Digi-Reel packaging. Active substitutes are available in Tape & Reel (TR) format: FTS 7B-18.432MBBK-T, ECS-184-20-33-TR, and QST QT532S-18.432MBBK-T. The TXC 7M-18.432MBBK-T packaging format is not specified in available documentation.

Q: Do all substitute parts meet RoHS compliance requirements?

A: Yes. All substitute parts listed carry RoHS compliance certification. The QST QT532S-18.432MBBK-T specifically carries ROHS3 compliance designation.

Q: What is the moisture sensitivity level for these crystal components?

A: All parts, including the main component and all substitutes, carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions for storage and handling.