CSX325FHC40.000M-UT Equivalent & Substitute Parts

Part Overview

The CSX325FHC40.000M-UT is a 40 MHz XO (Standard) CMOS oscillator manufactured by Citizen Finedevice Co Ltd, designed for applications requiring a 2.5V supply with standby power-down functionality. This component operates across the -20°C to 70°C temperature range with ±100ppm frequency stability and is packaged in a 4-SMD, No Lead configuration measuring 3.20mm × 2.50mm.

The CSX325FHC40.000M-UT has reached obsolete product status. Identifying equivalent substitute parts is necessary to maintain design continuity and ensure component availability for new production runs and field replacements.

Substiute Parts

CSX325FHC40.000M-UT

Citizen Finedevice Co LtdIn Stock: 978CSX325FHC40.000M-UT Datasheet

Current PartRFQ

ASE2-40.000MHZ-E-T

Abracon LLCIn Stock: 1513ASE2-40.000MHZ-E-T Datasheet

DirectRFQ

ASE3-40.000MHZ-KT

Abracon LLCIn Stock: 1095ASE3-40.000MHZ-KT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CSX325FHC40.000M-UT are identified based on the following critical parameters that must align for functional equivalence:

Primary Matching Criteria:

• Frequency: 40 MHz (exact match required)
• Output Type: CMOS
• Package Type: 4-SMD, No Lead
• Package Dimensions: 3.20mm × 2.50mm
• Moisture Sensitivity Level: MSL 1

Secondary Compatibility Parameters:

• Supply Voltage: 2.5V (primary requirement); 1.8V acceptable with design review
• Frequency Stability: ±100ppm or better
• Operating Temperature Range: Must encompass or exceed -20°C ~ 70°C
• Power Management Function: Standby/Power-Down or Enable/Disable capability

Parts are grouped into two categories: Direct substitutes (matching all primary criteria) and similar alternatives (matching core frequency and package specifications with noted parameter variations).

Parameter Comparison

Engineering Selection Recommendations

ASE2-40.000MHZ-E-T (Direct Substitute - Recommended)

The ASE2-40.000MHZ-E-T is the primary equivalent for the CSX325FHC40.000M-UT. This part matches all critical electrical and mechanical parameters: 40 MHz frequency, 2.5V supply voltage, ±100ppm frequency stability, identical package dimensions, and MSL 1 rating. The ASE2 series maintains active product status with ROHS3 compliance. The maximum supply current specification of 15mA exceeds the original 7mA; designs must verify this increased current draw is acceptable within power budgets. The seated height increases from 1.00mm to 1.20mm; PCB layout clearance must be confirmed. Packaging is available in Tape & Reel format.

ASE3-40.000MHZ-KT (Similar Alternative - Design Review Required)

The ASE3-40.000MHZ-KT provides a 40 MHz CMOS oscillator with improved frequency stability (±30ppm) and lower supply current (6mA). However, this part operates at 1.8V supply voltage, requiring circuit redesign or voltage regulation modifications. The operating temperature range begins at -10°C (versus -20°C for the original), which may be insufficient for applications requiring extended low-temperature operation. The power management function differs (Enable/Disable versus Standby Power-Down), necessitating firmware or control logic adjustments. This alternative is suitable only when supply voltage conversion is feasible and temperature range limitations are acceptable.

Both substitute parts are manufactured by Abracon LLC, an established oscillator supplier with active product lines and compliance certifications.

Frequently Asked Questions (FAQ)

Q: Can ASE2-40.000MHZ-E-T be used as a direct drop-in replacement?

A: The ASE2-40.000MHZ-E-T is electrically and mechanically compatible for most applications. The 0.20mm increase in seated height (1.20mm versus 1.00mm) must be verified against PCB clearance requirements. The increased maximum supply current (15mA versus 7mA) requires confirmation that power supply capacity and thermal design accommodate this change.

Q: What are the key differences between ASE2 and ASE3 series?

A: The ASE2-40.000MHZ-E-T operates at 2.5V with ±100ppm stability and Standby Power-Down function, matching the original specification. The ASE3-40.000MHZ-KT operates at 1.8V with superior ±30ppm stability and Enable/Disable function. Supply voltage and power management differences require design modifications for ASE3 implementation.

Q: Is the ASE3 suitable for low-temperature applications?

A: The ASE3-40.000MHZ-KT operating temperature range is -10°C to 70°C, which does not extend to the original -20°C minimum. Applications requiring operation below -10°C must use the ASE2-40.000MHZ-E-T or verify that the ASE3 temperature limitation is acceptable.

Q: Are both substitute parts RoHS compliant?

A: Yes. Both ASE2-40.000MHZ-E-T and ASE3-40.000MHZ-KT are ROHS3 compliant. The original CSX325FHC40.000M-UT RoHS status was not specified in available documentation.

Q: What is the impact of increased supply current in the ASE2?

A: The ASE2-40.000MHZ-E-T maximum supply current is 15mA compared to 7mA for the original part. Power supply capacity, voltage regulation headroom, and thermal dissipation must be evaluated. In most applications, this increase is manageable; however, designs with tight power budgets require detailed analysis.

Q: Can frequency stability differences affect circuit performance?

A: The ASE3-40.000MHZ-KT provides ±30ppm stability versus ±100ppm for both the original and ASE2 parts. Superior stability may benefit timing-sensitive applications but is not required for equivalence. Designs currently operating with ±100ppm stability do not require the ASE3 for this parameter alone.