9B-3.6864MAHK-B Crystal Oscillator Equivalent & Substitute Parts

Part Overview

The 9B-3.6864MAHK-B is a through-hole mounted crystal oscillator manufactured by TXC CORPORATION, operating at 3.6864 MHz with a frequency stability of ±30ppm and a load capacitance of 20pF. This component is housed in an HC-49/US package and is currently classified as obsolete. Due to its obsolete status and limited availability relative to active alternatives, identifying equivalent substitute parts is essential for ongoing system support and new design implementations.

Substiute Parts

9B-3.6864MAHK-B

TXC CORPORATIONIn Stock: 11279B-3.6864MAHK-B Datasheet

Current PartRFQ

HC49US-FF5F18-3.6864MHZ

ILSIIn Stock: 1559HC49US-FF5F18-3.6864MHZ Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 9B-3.6864MAHK-B are identified based on the following substitution criteria:

Mandatory Matching Parameters:

• Frequency: 3.6864 MHz (exact match required)
• Frequency Stability: ±30ppm (tolerance specification must be met or exceeded)
• Operating Temperature Range: -40°C to 85°C (minimum required range)
• Mounting Type: Through Hole (PCB assembly compatibility)
• Package / Case: HC-49/US (physical and electrical interface standard)

Allowable Variation Parameters:

• Load Capacitance: Substitutes may vary within ±2pF of the original specification (18pF to 22pF acceptable)
• ESR: Substitutes may vary within ±50 Ohms of the original specification (100 to 200 Ohms acceptable)

Compliance Considerations:

• RoHS3 compliance required for new designs
• ECCN and HTSUS classifications must remain consistent with export and tariff requirements

The substitute part HC49US-FF5F18-3.6864MHZ meets all mandatory matching parameters and falls within allowable variation ranges for load capacitance and ESR.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: HC49US-FF5F18-3.6864MHZ (ILSI)

The HC49US-FF5F18-3.6864MHZ is the qualified substitute for the obsolete 9B-3.6864MAHK-B based on the following engineering criteria:

1. Frequency and Stability Match: Both parts operate at 3.6864 MHz with ±30ppm frequency stability, ensuring equivalent timing performance in target applications.

2. Temperature Range Compatibility: Both parts maintain specifications across the -40°C to 85°C operating range, supporting identical environmental deployment scenarios.

3. Package and Mounting Compatibility: Both parts use HC-49/US through-hole packaging, enabling direct PCB footprint compatibility without redesign.

4. Parameter Tolerance Compliance: The 18pF load capacitance of the substitute (versus 20pF original) and 200 Ohm ESR (versus 150 Ohm original) fall within acceptable engineering tolerances for crystal oscillator circuit design. These variations do not compromise circuit functionality when properly tuned.

5. Regulatory Compliance: Both parts maintain ROHS3 compliance, satisfying current environmental and hazardous substance restrictions. Both share identical ECCN (EAR99) and HTSUS (8541.60.0030) classifications, ensuring consistent export and tariff treatment.

6. Active Manufacturing Status: The substitute part is currently in active production with confirmed inventory availability (1468 Pcs), providing supply chain continuity compared to the obsolete main part.

7. Moisture Sensitivity: The substitute part carries MSL 1 (Unlimited) rating, indicating superior moisture handling characteristics compared to the main part's Not Applicable designation.

Frequently Asked Questions (FAQ)

Q1: Can the HC49US-FF5F18-3.6864MHZ be used as a direct replacement for the 9B-3.6864MAHK-B without circuit modifications?

A: Yes. Both parts operate at identical frequency (3.6864 MHz) and frequency stability (±30ppm) with matching temperature ranges and HC-49/US packaging. The load capacitance difference (18pF vs 20pF) and ESR difference (200 Ohms vs 150 Ohms) are within acceptable engineering tolerances for crystal oscillator circuits. No circuit redesign is required.

Q2: What is the significance of the load capacitance difference between the two parts?

A: Load capacitance specifies the external capacitive load the crystal expects for optimal frequency accuracy. The 2pF difference (20pF to 18pF) is minor and falls within standard crystal oscillator circuit design margins. Existing load capacitors in the circuit will accommodate this variance without affecting frequency stability or timing performance.

Q3: Why is the ESR (Equivalent Series Resistance) higher in the substitute part?

A: ESR affects the energy required to sustain oscillation. The 50 Ohm increase (150 to 200 Ohms) remains within acceptable limits for HC-49/US crystals and does not compromise circuit startup or stability. Modern oscillator circuits are designed to accommodate ESR variations within this range.

Q4: Are there any compliance or certification differences between the two parts?

A: Both parts are ROHS3 compliant and share identical ECCN and HTSUS classifications. The substitute part carries MSL 1 (Unlimited) rating, indicating better moisture resistance than the main part. No compliance barriers exist for substitution.

Q5: What is the inventory status difference, and why does it matter?

A: The main part (9B-3.6864MAHK-B) is obsolete with limited stock (1040 Pcs). The substitute (HC49US-FF5F18-3.6864MHZ) is actively manufactured with higher inventory (1468 Pcs), ensuring long-term supply availability for production and support applications.

Q6: Are the physical dimensions compatible with existing PCB designs?

A: Yes. Both parts use HC-49/US packaging with minor dimensional variations (11.50mm vs 11.10mm length; 5.00mm vs 4.70mm width; 3.68mm vs 3.50mm height). These differences fall within HC-49/US tolerance specifications and do not affect PCB footprint compatibility or mounting reliability.