FST3125MTCX Equivalent & Substitute Parts

Part Overview

The FST3125MTCX is a bus switch logic IC manufactured by onsemi in a 14-TSSOP package configuration. This component functions as a 1 x 1:1 bus switch with 4 independent circuits, designed for single supply operation across 4V to 5.5V. The FST3125MTCX is classified as obsolete, necessitating identification of equivalent and substitute parts for ongoing design requirements and production continuity.

Substiute Parts

FST3125MTCX

onsemiIn Stock: 37870FST3125MTCX Datasheet

Current PartRFQ

FST3125DTR2G

onsemiIn Stock: 895FST3125DTR2G Datasheet

UpgradeRFQ

74CBTLV3125PW,118

Nexperia USA Inc.In Stock: 911674CBTLV3125PW,118 Datasheet

DirectRFQ

SN74CBT3125PW

Texas InstrumentsIn Stock: 1255SN74CBT3125PW Datasheet

DirectRFQ

SN74CBT3125PWR

Texas InstrumentsIn Stock: 5379SN74CBT3125PWR Datasheet

DirectRFQ

PI5C3125QE

Diodes IncorporatedIn Stock: 7405PI5C3125QE Datasheet

SimilarRFQ

SN74CBT3125CDBR

Texas InstrumentsIn Stock: 29146SN74CBT3125CDBR Datasheet

SimilarRFQ

SN74CBT3125CPW

Texas InstrumentsIn Stock: 924SN74CBT3125CPW Datasheet

SimilarRFQ

SN74CBT3125CPWR

Texas InstrumentsIn Stock: 2487SN74CBT3125CPWR Datasheet

SimilarRFQ

SN74CBT3125DBR

Texas InstrumentsIn Stock: 2220SN74CBT3125DBR Datasheet

SimilarRFQ

SN74CBT3125DBRE4

Texas InstrumentsIn Stock: 844SN74CBT3125DBRE4 Datasheet

SimilarRFQ

SN74CBT3125DGVR

Texas InstrumentsIn Stock: 3319SN74CBT3125DGVR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FST3125MTCX is determined by the following critical parameters:

Primary Compatibility Criteria:

• Circuit configuration: 1 x 1:1 with 4 independent circuits
• Package type: 14-TSSOP form factor (0.173", 4.40mm Width)
• Voltage supply architecture: Single supply operation
• Mounting type: Surface mount

Secondary Compatibility Criteria:

• Voltage supply range: Minimum 4V to 5.5V operation
• Operating temperature range: Support for -40°C to 85°C minimum
• RoHS3 compliance and MSL rating compatibility

Substitute parts are classified into three categories: upgrade options with extended temperature ranges, direct equivalents with identical electrical specifications, and similar alternatives with package variations or voltage adjustments.

Parameter Comparison

Engineering Selection Recommendations

Upgrade Path (Extended Temperature Range): FST3125DTR2G from onsemi provides identical electrical specifications to the FST3125MTCX with extended operating temperature range (-55°C to 125°C). This part maintains the same 14-TSSOP package and voltage supply parameters while offering improved thermal performance for demanding applications.

Direct Equivalents (14-TSSOP Package): SN74CBT3125CPW and SN74CBT3125CPWR from Texas Instruments are active production parts maintaining the 14-TSSOP package form factor. Both support 4.5V to 5.5V operation and -40°C to 85°C temperature range. SN74CBT3125CPWR is available in Tape & Reel packaging, while SN74CBT3125CPW is supplied in Tube format. Both parts carry ROHS3 compliance and MSL rating 1.

Alternative Voltage Profile (Low Voltage Operation): 74CBTLV3125PW from Nexperia USA Inc. operates at reduced voltage levels (2.3V to 3.6V) with extended temperature range (-40°C to 125°C). This part is suitable for applications requiring lower supply voltages and maintains the 14-TSSOP package configuration. Product status is active with full availability.

Package Variant Options (14-SSOP): SN74CBT3125CDBR and SN74CBT3125DBR from Texas Instruments utilize a 14-SSOP package (0.209", 5.30mm Width) instead of TSSOP. Both maintain 4.5V to 5.5V operation and -40°C to 85°C temperature specifications. SN74CBT3125CDBR is active production; SN74CBT3125DBR is Last Time Buy status.

Alternative Package (16-QSOP): PI5C3125QE from Diodes Incorporated uses a 16-QSOP package configuration. This part maintains 1 x 1:1 circuit topology with 4 independent circuits and 4.5V to 5.5V operation. Product status is Last Time Buy.

Frequently Asked Questions (FAQ)

Q: Can FST3125MTCX be directly replaced with SN74CBT3125CPW? A: Yes. Both parts share identical circuit configuration (1 x 1:1), package type (14-TSSOP), voltage range (4.5V to 5.5V minimum), and operating temperature specifications (-40°C to 85°C). SN74CBT3125CPW is an active production part from Texas Instruments. Packaging format differs (Tube vs. Tape & Reel), which does not affect electrical compatibility.

Q: What is the difference between 14-TSSOP and 14-SSOP packages? A: Both packages contain 14 pins in surface mount configuration. The primary difference is package width: 14-TSSOP measures 0.173" (4.40mm) width, while 14-SSOP measures 0.209" (5.30mm) width. PCB layout and footprint designs must accommodate the specific package width. Electrical specifications remain identical between parts using these different packages.

Q: Is 74CBTLV3125PW compatible with 5V supply designs? A: No. The 74CBTLV3125PW operates at 2.3V to 3.6V supply voltage, which is incompatible with standard 5V designs. This part is suitable only for low-voltage applications. For 5V designs, use SN74CBT3125CPW, SN74CBT3125CPWR, or FST3125DTR2G.

Q: Why is FST3125DTR2G classified as an upgrade option? A: FST3125DTR2G maintains all electrical and package specifications of FST3125MTCX while extending the operating temperature range from -40°C to 85°C to -55°C to 125°C. This broader temperature specification accommodates applications requiring operation in extreme thermal environments without changing circuit design or PCB layout.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All substitute parts listed carry ROHS3 compliance certification and MSL rating 1 (Unlimited), matching the environmental and reliability standards of the original FST3125MTCX.

Q: What packaging formats are available for active production equivalents? A: Active production equivalents SN74CBT3125CPW and SN74CBT3125CPWR are available in Tube and Tape & Reel formats respectively. 74CBTLV3125PW is supplied in Cut Tape & Digi-Reel format. Selection depends on procurement volume and assembly line requirements.