7B-26.000MDDI-T Crystal Oscillator Equivalent & Substitute Parts

Part Overview

The 7B-26.000MDDI-T is a 26 MHz fundamental mode crystal oscillator manufactured by TXC CORPORATION, designed for surface mount applications in 4-SMD, No Lead package configuration. This component operates at ±20ppm frequency stability with 16pF load capacitance and 40 Ohms equivalent series resistance (ESR). The part is classified as obsolete, necessitating identification of active equivalent alternatives to maintain design continuity and ensure supply chain availability for new production and legacy system support.

Substiute Parts

7B-26.000MDDI-T

TXC CORPORATIONIn Stock: 8467B-26.000MDDI-T Datasheet

Current PartRFQ

7V-26.000MDDE-T

TXC CORPORATIONIn Stock: 6917V-26.000MDDE-T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 7B-26.000MDDI-T is determined by the following critical parameters:

Primary Matching Criteria:

• Frequency: 26.0000 MHz (exact match required)
• Frequency Stability: ±20ppm (exact match required)
• Operating Mode: Fundamental (exact match required)
• Operating Temperature Range: -20°C to +70°C (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Package Type: 4-SMD, No Lead (exact match required)
• RoHS Compliance: Required
• MSL Rating: 1 (Unlimited) (exact match required)

Secondary Compatibility Parameters:

• Load Capacitance: 16pF (primary specification; 12pF acceptable with circuit design verification)
• ESR: 40 Ohms (primary specification; 60 Ohms acceptable with circuit design verification)
• Physical Dimensions: Variations permitted within SMD assembly tolerances

The 7V-26.000MDDE-T meets all primary matching criteria and represents an active product alternative. Secondary parameter variations (load capacitance 12pF vs. 16pF; ESR 60 Ohms vs. 40 Ohms) require circuit-level evaluation to confirm compatibility with the application's oscillator circuit design.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: 7V-26.000MDDE-T

The 7V-26.000MDDE-T is the qualified substitute for the obsolete 7B-26.000MDDI-T. Selection rationale:

1. Frequency Alignment: Both parts operate at 26.0000 MHz with identical ±20ppm stability and tolerance specifications, ensuring frequency-critical circuit requirements are met.

2. Package Compatibility: Both components use 4-SMD, No Lead surface mount packaging with identical electrical interface characteristics, permitting direct PCB footprint compatibility.

3. Environmental Compliance: Both parts maintain RoHS compliance and MSL 1 (Unlimited) moisture sensitivity rating, satisfying regulatory and manufacturing process requirements.

4. Product Status: The 7V-26.000MDDE-T is classified as Active, ensuring ongoing availability, supply chain support, and manufacturing continuity compared to the obsolete 7B-26.000MDDI-T.

5. Secondary Parameter Variations: Load capacitance differs (12pF vs. 16pF) and ESR differs (60 Ohms vs. 40 Ohms). These variations require validation against the specific oscillator circuit design to confirm frequency accuracy and startup characteristics remain within system specifications.

Frequently Asked Questions (FAQ)

Q: Can the 7V-26.000MDDE-T be used as a direct drop-in replacement for the 7B-26.000MDDI-T?

A: The 7V-26.000MDDE-T shares identical frequency, stability, operating temperature, package type, and compliance specifications. However, the load capacitance (12pF vs. 16pF) and ESR (60 Ohms vs. 40 Ohms) differ. Direct substitution requires circuit design verification to confirm the oscillator circuit compensates for these parameter variations and maintains frequency accuracy within system tolerance.

Q: What is the significance of the load capacitance difference between these parts?

A: Load capacitance affects the crystal's resonant frequency in the oscillator circuit. The 7B-26.000MDDI-T specifies 16pF load capacitance, while the 7V-26.000MDDE-T specifies 12pF. The oscillator circuit's load capacitance network must match the crystal's specification. Mismatched load capacitance can result in frequency offset. Circuit design review is required to determine if the existing load capacitance network is compatible with the 12pF specification or requires adjustment.

Q: What does the ESR difference (40 Ohms vs. 60 Ohms) mean for circuit performance?

A: Equivalent Series Resistance (ESR) affects oscillator startup time, power consumption, and frequency stability margin. The 7V-26.000MDDE-T has higher ESR (60 Ohms vs. 40 Ohms), which may increase startup time and power draw. The oscillator circuit design must confirm that the drive level and amplifier characteristics accommodate the higher ESR without compromising startup reliability or frequency accuracy.

Q: Are both parts RoHS compliant?

A: Yes, both the 7B-26.000MDDI-T and 7V-26.000MDDE-T are RoHS compliant and carry MSL 1 (Unlimited) moisture sensitivity rating, meeting regulatory and manufacturing process requirements.

Q: Why is the 7B-26.000MDDI-T classified as obsolete?

A: The 7B-26.000MDDI-T is marked as obsolete, indicating TXC CORPORATION has discontinued production. The 7V-26.000MDDE-T (Active status) is the recommended alternative for new designs and ongoing production support.

Q: What packaging format is available for the 7V-26.000MDDE-T?

A: The 7V-26.000MDDE-T is supplied in Tape & Reel (TR) packaging format, standard for high-volume surface mount assembly operations.