ASCSM-1.544MHZ-LR-T Equivalent & Substitute Parts

Part Overview

The ASCSM-1.544MHZ-LR-T is a MEMS-based XO (Standard) oscillator manufactured by Abracon LLC, operating at 1.544 MHz with CMOS output. This component is designed for applications requiring low-voltage operation (1.7V ~ 3.6V) with enable/disable functionality in a compact 4-UFBGA package. The product is currently obsolete, necessitating identification of functionally equivalent alternatives to maintain design continuity and ensure component availability for production and maintenance applications.

Substiute Parts

ASCSM-1.544MHZ-LR-T

Abracon LLCIn Stock: 938ASCSM-1.544MHZ-LR-T Datasheet

Current PartRFQ

ASCO-1.544MHZ-L-T3

Abracon LLCIn Stock: 897ASCO-1.544MHZ-L-T3 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ASCSM-1.544MHZ-LR-T must satisfy the following criteria based on provided electrical and mechanical parameters:

Critical Matching Parameters:

• Frequency: 1.544 MHz (exact match required)
• Output Type: CMOS
• Function: Enable/Disable capability
• Operating Temperature Range: -40°C ~ 85°C minimum
• RoHS3 Compliance

Allowable Variations:

• Voltage Supply Range: The substitute ASCO-1.544MHZ-L-T3 operates at 3.3V fixed supply, which is within the original part's 1.7V ~ 3.6V range. This represents a narrower but compatible voltage specification.
• Frequency Stability: The substitute specifies ±50ppm versus the original ±25ppm. This represents a relaxed tolerance that may be acceptable depending on application requirements.
• Base Resonator Technology: Substitution from MEMS to Crystal-based resonator is permitted when frequency and stability requirements are met.
• Package Type: Transition from 4-UFBGA/CSPBGA to 4-SMD No Lead represents a different form factor but maintains equivalent electrical functionality and PCB footprint compatibility considerations.
• Current Consumption: The substitute draws 4.5mA maximum versus 6.5mA, representing improved efficiency.

Parameter Comparison

Engineering Selection Recommendations

The ASCO-1.544MHZ-L-T3 is a direct functional substitute for the obsolete ASCSM-1.544MHZ-LR-T based on the following engineering criteria:

Compliance & Availability:

• Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity.
• The substitute is currently in active production status with confirmed inventory availability (884 Pcs), whereas the original part is obsolete.

Electrical Compatibility:

• Identical frequency (1.544 MHz) and CMOS output ensure signal compatibility with existing circuit designs.
• The 3.3V fixed supply requirement falls within the original part's 1.7V ~ 3.6V operating range, making it compatible with systems designed for the wider voltage specification.
• Enable/Disable functionality is preserved, maintaining power management capabilities.

Performance Considerations:

• Frequency stability specification relaxes from ±25ppm to ±50ppm. Applications with stringent frequency tolerance requirements must evaluate this change against system specifications.
• Current consumption improves from 6.5mA to 4.5mA, providing power efficiency benefits.

Physical Integration:

• Package transition from 4-UFBGA/CSPBGA to 4-SMD No Lead requires PCB layout verification. Physical dimensions are comparable (1.79mm x 1.25mm versus 1.60mm x 1.20mm), and height specifications are equivalent (0.69mm versus 0.70mm).

Frequently Asked Questions (FAQ)

Q: Can the ASCO-1.544MHZ-L-T3 directly replace the ASCSM-1.544MHZ-LR-T without circuit modifications?

A: Electrical substitution is direct for applications operating at 3.3V supply voltage. Systems designed for the full 1.7V ~ 3.6V range of the original part must confirm that 3.3V fixed supply is acceptable. PCB layout changes are required due to package type transition from BGA to SMD.

Q: What is the impact of the frequency stability change from ±25ppm to ±50ppm?

A: Frequency stability determines long-term frequency accuracy. The relaxed ±50ppm specification may affect applications with tight frequency tolerance requirements. System designers must verify that the substitute's stability meets application performance criteria.

Q: Are there compatibility concerns with the package change from 4-UFBGA to 4-SMD No Lead?

A: Package type change requires PCB footprint redesign and revalidation of solder reflow profiles. Physical dimensions are comparable, but assembly process parameters differ between BGA and SMD technologies. Consult PCB design guidelines for the 4-SMD No Lead package.

Q: Does the substitute part maintain the same moisture sensitivity level?

A: The original part specifies MSL 1 (Unlimited). The substitute lists MSL as Not Applicable, indicating different moisture handling requirements. Verify storage and handling procedures with the substitute part datasheet.

Q: Is the lower current consumption of the substitute part a design advantage?

A: The substitute draws 4.5mA maximum versus 6.5mA, representing approximately 31% reduction in supply current. This provides power efficiency benefits for battery-powered or power-constrained applications.