LFXTAL019949 Equivalent & Substitute Parts Reference

Part Overview

The LFXTAL019949 is a 5 MHz fundamental mode crystal oscillator manufactured by IQD Frequency Products, housed in an HC-49/US surface mount package. This component is designed for applications requiring precise frequency reference with tight tolerance specifications. The part is currently in active production status with 1069 units available in stock.

Substitute parts are identified when equivalent electrical performance can be maintained across critical parameters including frequency, load capacitance, ESR, operating temperature range, and mechanical compatibility. Alternative sources may be required due to supply chain considerations, lead time requirements, or inventory availability.

Substiute Parts

LFXTAL019949

IQD Frequency ProductsIn Stock: 1092LFXTAL019949 Datasheet

Current PartRFQ

ABLS-5.000MHZ-B4-T

Abracon LLCIn Stock: 6777ABLS-5.000MHZ-B4-T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LFXTAL019949 is determined by strict alignment of the following critical parameters:

Mandatory Matching Parameters:

• Frequency: 5.0000 MHz (exact match required)
• Frequency Tolerance: ±30 ppm (exact match required)
• Operating Mode: Fundamental
• Package / Case: HC-49/US
• Mounting Type: Surface Mount
• Operating Temperature Range: -20°C to 70°C (minimum coverage required)

Allowable Variation Parameters:

• Load Capacitance: ±2 pF variance acceptable within circuit design margins
• ESR: ±15 Ohms variance acceptable within oscillator circuit specifications
• Physical dimensions: Minor variations within HC-49/US standard envelope permitted

The ABLS-5.000MHZ-B4-T from Abracon LLC meets all mandatory matching criteria and falls within allowable variation ranges for load capacitance and ESR, qualifying it as a direct substitute.

Parameter Comparison

Engineering Selection Recommendations

LFXTAL019949 (IQD Frequency Products):

• Primary selection when IQD supply chain is preferred
• Active production status with 1069 units in current inventory
• ROHS3 compliant; REACH unaffected status
• Established qualification history in existing designs

ABLS-5.000MHZ-B4-T (Abracon LLC):

• Alternative source when IQD lead times exceed project requirements
• Active production status with 6731 units in current inventory
• ROHS3 compliant; REACH affected status
• Load capacitance specification (18 pF) requires circuit verification for oscillator loop stability
• ESR specification (120 Ohms) is within acceptable operating range for HC-49/US fundamental mode crystals

Both parts maintain identical frequency, tolerance, stability, operating temperature, and package specifications. Selection between these parts should be based on supply availability, lead time requirements, and circuit design validation for the 2 pF load capacitance difference.

Frequently Asked Questions (FAQ)

Q: Can ABLS-5.000MHZ-B4-T be used as a direct drop-in replacement for LFXTAL019949?

A: The ABLS-5.000MHZ-B4-T is electrically and mechanically compatible with the LFXTAL019949 for applications where the 2 pF load capacitance difference (20 pF vs. 18 pF) does not affect oscillator circuit performance. Circuit validation is required to confirm oscillator loop stability with the lower load capacitance specification.

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

A: Load capacitance affects the oscillator circuit's resonant frequency and startup characteristics. The LFXTAL019949 specifies 20 pF load capacitance, while the ABLS-5.000MHZ-B4-T specifies 18 pF. This 2 pF difference may require adjustment to external load capacitors in the oscillator circuit to maintain frequency accuracy within ±30 ppm tolerance.

Q: Are both parts suitable for the same operating temperature range?

A: Yes. Both the LFXTAL019949 and ABLS-5.000MHZ-B4-T operate across the identical temperature range of -20°C to 70°C with ±50 ppm frequency stability specification.

Q: What is the difference in ESR between these crystals?

A: The LFXTAL019949 has an ESR of 130 Ohms, while the ABLS-5.000MHZ-B4-T has an ESR of 120 Ohms. This 10 Ohm difference is within acceptable operating margins for HC-49/US fundamental mode crystals and does not affect circuit compatibility.

Q: Are both parts RoHS compliant?

A: Yes. Both the LFXTAL019949 and ABLS-5.000MHZ-B4-T are ROHS3 compliant. The LFXTAL019949 has REACH unaffected status, while the ABLS-5.000MHZ-B4-T has REACH affected status.

Q: What packaging format is used for both parts?

A: Both parts are supplied in Tape & Reel (TR) packaging for automated assembly processes and are configured for surface mount assembly on standard PCB equipment.