9B-18.432MAAJ-B Crystal Equivalent & Substitute Parts

Part Overview

The 9B-18.432MAAJ-B is an 18.432 MHz through-hole crystal manufactured by TXC CORPORATION, designed for fundamental mode operation with 18pF load capacitance and 30 Ohms equivalent series resistance. This component operates across the temperature range of -20°C to 70°C with ±30ppm frequency stability.

The 9B-18.432MAAJ-B is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this frequency specification.

Substiute Parts

9B-18.432MAAJ-B

TXC CORPORATIONIn Stock: 11789B-18.432MAAJ-B Datasheet

Current PartRFQ

HC49US-FF3F18-18.4320MHZ

ILSIIn Stock: 1301HC49US-FF3F18-18.4320MHZ Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 9B-18.432MAAJ-B is determined by the following critical parameters:

Frequency Match: The substitute part must operate at 18.432 MHz to maintain circuit timing specifications.

Load Capacitance Match: The substitute part must have 18pF load capacitance to ensure compatibility with oscillator circuit design.

Frequency Stability Match: The substitute part must maintain ±30ppm frequency stability to meet application tolerance requirements.

Operating Mode Match: The substitute part must operate in fundamental mode to align with circuit architecture.

Operating Temperature Range Match: The substitute part must support the -20°C to 70°C operating temperature range.

Package Match: The substitute part must use HC-49/US through-hole packaging to ensure mechanical and electrical compatibility with existing PCB layouts.

ESR Tolerance: The substitute part may have ESR values within acceptable operating margins of the original specification. The original part specifies 30 Ohms ESR; substitute parts with higher ESR values remain functionally compatible provided the oscillator circuit design accommodates the variance.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: HC49US-FF3F18-18.4320MHZ (ILSI)

The HC49US-FF3F18-18.4320MHZ from ILSI is a direct functional equivalent to the obsolete 9B-18.432MAAJ-B. This substitute part satisfies all critical electrical parameters: identical frequency (18.432 MHz), frequency stability (±30ppm), load capacitance (18pF), operating mode (fundamental), and temperature range (-20°C to 70°C).

The substitute part is classified as active product status, ensuring ongoing availability and supply chain continuity. Both the original and substitute parts maintain ROHS3 compliance and operate under the same ECCN and HTSUS classifications.

The ESR variance (40 Ohms versus 30 Ohms) represents a 10 Ohm increase. This variance is within acceptable operating margins for HC-49/US crystal oscillators and does not compromise circuit functionality when the oscillator design accommodates standard ESR tolerances.

Physical dimensions show minor variations: the substitute part measures 11.10mm x 4.70mm (versus 11.50mm x 5.00mm) with a maximum seated height of 3.50mm (versus 3.68mm). These dimensional differences remain within HC-49/US package specifications and are compatible with standard through-hole PCB layouts.

The substitute part is available in bulk packaging with 1255 pieces in stock, providing immediate availability for production requirements.

Frequently Asked Questions (FAQ)

Q: Can the HC49US-FF3F18-18.4320MHZ substitute directly for the 9B-18.432MAAJ-B without circuit modifications?

A: Yes. The substitute part matches all critical electrical parameters including frequency, frequency stability, load capacitance, operating mode, and temperature range. The 10 Ohm ESR variance is within acceptable operating margins for HC-49/US crystal oscillators and does not require circuit modifications.

Q: What is the significance of the ESR difference between the two parts?

A: The original part specifies 30 Ohms ESR; the substitute part specifies 40 Ohms ESR. This 10 Ohm variance affects oscillator startup characteristics and power consumption marginally. Standard oscillator circuit designs accommodate ESR tolerances within this range. Verification of oscillator performance is not required for typical applications.

Q: Are the physical dimensions compatible with existing PCB layouts?

A: Yes. Both parts use HC-49/US through-hole packaging. The substitute part dimensions (11.10mm x 4.70mm x 3.50mm maximum height) are slightly smaller than the original (11.50mm x 5.00mm x 3.68mm maximum height). These differences remain within HC-49/US package specifications and are compatible with standard through-hole PCB footprints.

Q: What is the product status difference between the two parts?

A: The 9B-18.432MAAJ-B is classified as obsolete, indicating discontinued manufacturing. The HC49US-FF3F18-18.4320MHZ is classified as active, indicating current production and ongoing availability. This status difference makes the substitute part suitable for long-term supply chain planning.

Q: Do both parts meet the same compliance requirements?

A: Yes. Both parts are ROHS3 compliant and operate under identical ECCN (EAR99) and HTSUS (8541.60.0050) classifications. The original part is REACH Affected; the substitute part is REACH Unaffected. Both parts are suitable for applications requiring regulatory compliance in their respective jurisdictions.

Q: What is the inventory status for the substitute part?

A: The HC49US-FF3F18-18.4320MHZ is available with 1255 pieces in stock as new original components in bulk packaging, providing immediate availability for production requirements.