HCM4940000000ABJT Equivalent & Substitute Parts

Part Overview

The HCM4940000000ABJT is a 40 MHz crystal oscillator manufactured by Citizen Finedevice Co Ltd, designed for surface mount applications in the HC-49/US package. This active product operates in 3rd overtone mode with 18pF load capacitance and 100 Ohms equivalent series resistance. Finding equivalent substitute parts may be necessary due to inventory constraints, lead time requirements, or specific application performance needs while maintaining electrical and mechanical compatibility.

Substiute Parts

HCM4940000000ABJT

Citizen Finedevice Co LtdIn Stock: 1691HCM4940000000ABJT Datasheet

Current PartRFQ

ABLS2-40.000MHZ-D4YF-T

Abracon LLCIn Stock: 2208ABLS2-40.000MHZ-D4YF-T Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the HCM4940000000ABJT is determined by the following critical parameters:

• Frequency: 40 MHz (exact match required)
• Frequency Tolerance: ±30ppm (maximum allowable deviation)
• Load Capacitance: 18pF (exact match required)
• Package / Case: HC-49/US (mechanical and electrical interface compatibility)
• Mounting Type: Surface Mount (assembly process compatibility)

The ABLS2-40.000MHZ-D4YF-T from Abracon LLC meets these core substitution criteria. While differences exist in ESR, operating mode, and temperature range, these variations do not prevent functional equivalence when the primary electrical parameters align.

Parameter Comparison

Engineering Selection Recommendations

Both the HCM4940000000ABJT and ABLS2-40.000MHZ-D4YF-T are active products with ROHS3 compliance, ensuring regulatory alignment for current manufacturing standards. The Abracon substitute offers improved frequency stability (±30ppm vs ±50ppm) and an extended operating temperature range (-40°C ~ 85°C vs -10°C ~ 60°C), which may provide performance advantages in demanding thermal environments. The lower ESR of the Abracon part (40 Ohms vs 100 Ohms) reduces power consumption and heat generation. Both parts maintain identical frequency, load capacitance, and package specifications, confirming mechanical and electrical interface compatibility. Selection should be based on application-specific temperature requirements and power budget constraints.

Frequently Asked Questions (FAQ)

Q: Can the ABLS2-40.000MHZ-D4YF-T directly replace the HCM4940000000ABJT in existing designs?

A: Yes, both parts share identical frequency (40 MHz), load capacitance (18pF), and HC-49/US package specifications. The mechanical footprint and electrical interface are compatible for direct substitution in surface mount applications.

Q: What is the significance of the different operating modes (3rd Overtone vs Fundamental)?

A: Operating mode affects the internal resonance characteristics of the crystal. The Abracon part operates in fundamental mode while the Citizen part operates in 3rd overtone mode. Both achieve the same 40 MHz output frequency and meet the ±30ppm tolerance requirement, making them functionally equivalent for circuit applications.

Q: Why does the Abracon part have lower ESR (40 Ohms vs 100 Ohms)?

A: ESR differences reflect manufacturing design variations between manufacturers. Lower ESR in the Abracon part results in reduced power dissipation and improved frequency stability, which may be beneficial in power-sensitive or thermally constrained applications.

Q: Are there temperature range considerations for substitution?

A: The Abracon ABLS2-40.000MHZ-D4YF-T operates across -40°C ~ 85°C, while the Citizen HCM4940000000ABJT operates across -10°C ~ 60°C. If your application requires operation below -10°C or above 60°C, the Abracon part provides extended capability. For applications within -10°C ~ 60°C, both parts are suitable.

Q: Do packaging differences affect PCB assembly?

A: Both parts use identical HC-49/US packaging and surface mount mounting type. The Abracon part has a lower seated height (3.30mm vs 4.30mm), which may provide clearance advantages in space-constrained designs but does not prevent substitution.

Q: Are both parts RoHS compliant?

A: Yes, both the HCM4940000000ABJT and ABLS2-40.000MHZ-D4YF-T are ROHS3 compliant, meeting current environmental and regulatory requirements for electronic component manufacturing.