TC-4.000MBD-T MEMS Oscillator Equivalent & Substitute Parts

Part Overview

The TC-4.000MBD-T is a 4 MHz MEMS-based XO (Standard) oscillator manufactured by TXC CORPORATION. This component operates at 3.3V with CMOS output, Enable/Disable function, and is housed in a 4-SMD, No Lead package. The part is currently classified as Obsolete, making identification of functionally equivalent substitutes essential for ongoing design support and production continuity.

Substiute Parts

TC-4.000MBD-T

TXC CORPORATIONIn Stock: 3119TC-4.000MBD-T Datasheet

Current PartRFQ

7X-4.000MBD-T

TXC CORPORATIONIn Stock: 7307X-4.000MBD-T Datasheet

DirectRFQ

ASE-4.000MHZ-L-R-T

Abracon LLCIn Stock: 1262ASE-4.000MHZ-L-R-T Datasheet

DirectRFQ

FK0400018Q

Diodes IncorporatedIn Stock: 984FK0400018Q Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the TC-4.000MBD-T is determined by strict alignment of the following parameters:

• Frequency: 4 MHz (exact match required)
• Output Type: CMOS (exact match required)
• Supply Voltage: 3.3V (exact match required)
• Function: Enable/Disable (exact match required)
• Frequency Stability: ±25ppm (exact match required)
• Operating Temperature Range: -40°C ~ 85°C (exact match required)
• Package / Case: 4-SMD, No Lead (exact match required)
• Physical Dimensions: 0.126" L x 0.098" W (3.20mm x 2.50mm) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Moisture Sensitivity Level: 1 (Unlimited) (exact match required)

All three substitute parts listed below meet these criteria. Differences in base resonator technology (MEMS versus Crystal), current consumption, and product status are secondary considerations that do not affect functional substitution within the specified electrical and mechanical parameters.

Parameter Comparison

Engineering Selection Recommendations

For Active Production Designs:

The 7X-4.000MBD-T (TXC CORPORATION) is the primary substitute. It maintains the same manufacturer lineage as the obsolete TC-4.000MBD-T, shares identical electrical specifications and package dimensions, and is currently in Active product status. This part is available in Cut Tape (CT) & Digi-Reel® packaging.

For Compliance-Critical Applications:

The ASE-4.000MHZ-L-R-T (Abracon LLC) and FK0400018Q (Diodes Incorporated) are both ROHS3 Compliant and REACH Unaffected. The FK0400018Q carries AEC-Q200 automotive qualification, making it suitable for automotive and high-reliability applications. Both parts are available in Tape & Reel (TR) packaging.

For Power-Constrained Designs:

The ASE-4.000MHZ-L-R-T offers the lowest active supply current at 7mA maximum, with an additional 10µA disable current specification. The FK0400018Q provides 8mA maximum active current with identical disable current specification. Both represent significant power reduction compared to the original TC-4.000MBD-T (25mA) and the 7X-4.000MBD-T (15mA).

Height Consideration:

The TC-4.000MBD-T has a seated height of 0.031" (0.80mm), which is lower than all substitute parts. The 7X-4.000MBD-T measures 0.043" (1.10mm), the FK0400018Q measures 0.045" (1.15mm), and the ASE-4.000MHZ-L-R-T measures 0.047" (1.20mm). PCB layout clearance verification is required for space-constrained applications.

Frequently Asked Questions (FAQ)

Q: Can the 7X-4.000MBD-T directly replace the TC-4.000MBD-T without PCB modifications?

A: The 7X-4.000MBD-T is electrically and mechanically compatible with the TC-4.000MBD-T. Both parts share identical package type (4-SMD, No Lead), footprint dimensions (0.126" L x 0.098" W), and all critical electrical parameters (frequency, output type, supply voltage, function, stability, and operating temperature). However, the 7X-4.000MBD-T has a maximum seated height of 0.043" compared to the TC-4.000MBD-T's 0.031". Verify PCB clearance above the component to confirm no interference with overlying components or enclosure.

Q: What is the difference between MEMS and Crystal base resonators in these oscillators?

A: The TC-4.000MBD-T uses a MEMS (Micro-Electro-Mechanical Systems) resonator, while the 7X-4.000MBD-T, ASE-4.000MHZ-L-R-T, and FK0400018Q use Crystal resonators. Both technologies deliver identical electrical performance within the specified parameters for this application. MEMS technology typically offers improved shock and vibration resistance, while crystal technology is well-established in production environments. Selection between these technologies depends on application-specific environmental requirements not specified in the electrical parameters.

Q: Are there packaging differences between the substitute parts?

A: Yes. The 7X-4.000MBD-T is available in Cut Tape (CT) & Digi-Reel® packaging, suitable for automated pick-and-place assembly. The ASE-4.000MHZ-L-R-T and FK0400018Q are supplied in Tape & Reel (TR) packaging, also suitable for automated assembly. Verify your procurement and assembly processes support the available packaging format for each part.

Q: Which substitute part is recommended for automotive applications?

A: The FK0400018Q carries AEC-Q200 automotive qualification rating. This part is suitable for automotive-grade applications requiring formal qualification documentation. The ASE-4.000MHZ-L-R-T and 7X-4.000MBD-T do not carry automotive ratings and should not be used in applications requiring AEC-Q200 compliance.

Q: What is the significance of the Current - Supply (Disable) specification?

A: The Current - Supply (Disable) specification indicates the quiescent current drawn when the oscillator's Enable/Disable function is activated to disable the output. The ASE-4.000MHZ-L-R-T and FK0400018Q both specify 10µA disable current, enabling low-power standby operation. The TC-4.000MBD-T and 7X-4.000MBD-T do not provide this specification. For power-managed applications utilizing the Enable/Disable function, the ASE-4.000MHZ-L-R-T or FK0400018Q are preferred.

Q: Can I use these parts interchangeably in existing designs?

A: All four parts meet the core electrical and mechanical substitution criteria: 4 MHz frequency, CMOS output, 3.3V supply, Enable/Disable function, ±25ppm stability, -40°C to 85°C operating range, 4-SMD No Lead package, and 3.20mm x 2.50mm footprint. Interchangeability is confirmed for these parameters. However, verify PCB clearance for the increased seated heights of substitute parts, and confirm packaging format compatibility with your assembly process.

Q: What compliance certifications apply to each part?

A: The TC-4.000MBD-T (Obsolete) does not specify RoHS or REACH status. The 7X-4.000MBD-T does not specify RoHS or REACH status. The ASE-4.000MHZ-L-R-T is ROHS3 Compliant and REACH Unaffected. The FK0400018Q is ROHS3 Compliant and REACH Unaffected. All four parts are classified as EAR99 for export control purposes and share the same HTSUS code (8542.39.0001). For designs requiring RoHS3 compliance, select the ASE-4.000MHZ-L-R-T or FK0400018Q.