9B20000077 Crystal Equivalent & Substitute Parts

Part Overview

The 9B20000077 is a 20 MHz through-hole crystal manufactured by TXC CORPORATION, designed for fundamental mode operation with 20pF load capacitance and 30 Ohms equivalent series resistance. The device operates across -10°C to 60°C with ±30ppm frequency stability and is packaged in HC-49/US form factor.

This part carries Obsolete product status. Identifying equivalent and substitute components is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements for systems utilizing this crystal specification.

Substiute Parts

9B20000077

TXC CORPORATIONIn Stock: 8259B20000077 Datasheet

Current PartRFQ

HC-49/U-S20000000AAJB

Citizen Finedevice Co LtdIn Stock: 963HC-49/U-S20000000AAJB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 9B20000077 is determined by strict alignment of the following critical parameters:

Mandatory Matching Parameters:

• Frequency: 20.0000 MHz (exact match required)
• Frequency Stability: ±30ppm (tolerance specification)
• Operating Mode: Fundamental
• Package / Case: HC-49/US (mechanical and electrical interface)
• Mounting Type: Through Hole
• Operating Temperature Range: -10°C to 60°C (minimum)

Allowable Variation Parameters:

• Load Capacitance: 18pF to 20pF (within typical circuit tolerance)
• Equivalent Series Resistance (ESR): 30 to 50 Ohms (within acceptable oscillator circuit margin)

The substitute part HC-49/U-S20000000AAJB from Citizen Finedevice Co Ltd meets all mandatory parameters and operates within allowable variation ranges for load capacitance and ESR.

Parameter Comparison

Engineering Selection Recommendations

The HC-49/U-S20000000AAJB from Citizen Finedevice Co Ltd is a direct substitute for the obsolete 9B20000077. Selection is supported by the following factors:

Compliance & Certification: Both parts maintain ROHS3 compliance and operate under identical frequency and stability specifications. The substitute part carries Active product status, ensuring ongoing availability and supply chain support.

Electrical Compatibility: The 2pF reduction in load capacitance (20pF to 18pF) and 20 Ohm increase in ESR (30 to 50 Ohms) remain within standard oscillator circuit design margins. These variations do not compromise frequency accuracy or circuit performance when the oscillator is properly tuned.

Mechanical Compatibility: Both parts utilize HC-49/US packaging with through-hole mounting. Physical dimensions are equivalent, enabling direct PCB footprint compatibility without layout modification.

Supply Availability: The substitute part is currently in stock with 903 pieces available, compared to the obsolete main part status. This ensures reliable procurement for production and maintenance applications.

Frequently Asked Questions (FAQ)

Q: Can the HC-49/U-S20000000AAJB directly replace the 9B20000077 without circuit modification?

A: Yes. Both parts operate at 20.0000 MHz with ±30ppm stability in HC-49/US packaging. The 2pF load capacitance difference and 20 Ohm ESR increase are within standard oscillator design tolerances and do not require circuit redesign.

Q: What is the significance of the load capacitance difference between 20pF and 18pF?

A: Load capacitance specifies the external capacitive load at which the crystal operates at its specified frequency. The 2pF difference is accommodated by standard oscillator circuit design practices and does not affect frequency accuracy or stability performance.

Q: Does the higher ESR of the substitute part (50 Ohms vs. 30 Ohms) affect circuit performance?

A: No. The 50 Ohm ESR remains within acceptable limits for fundamental mode 20 MHz crystals. Oscillator circuits are designed to accommodate ESR variations within this range without performance degradation.

Q: Are both parts RoHS compliant?

A: Yes. Both the 9B20000077 and HC-49/U-S20000000AAJB are ROHS3 compliant, meeting environmental and regulatory requirements for electronic component manufacturing and use.

Q: What is the difference between the Obsolete and Active product status?

A: Obsolete status indicates the 9B20000077 is no longer manufactured or supported by TXC CORPORATION. Active status for the HC-49/U-S20000000AAJB confirms ongoing production and availability from Citizen Finedevice Co Ltd, ensuring reliable supply for current and future applications.

Q: Can the substitute part be used in existing designs without qualification testing?

A: Electrical and mechanical compatibility is confirmed through parameter alignment. Design validation procedures specific to your application should be followed per standard engineering practice.