SN74LVC2G66DCUT Equivalent & Substitute Parts

Part Overview

The SN74LVC2G66DCUT is a 2-circuit IC switch manufactured by Texas Instruments, configured as a single-pole single-throw (SPST) normally open switch with 1:1 multiplexer/demultiplexer functionality. This device operates across a supply voltage range of 1.65V to 5.5V and features a maximum on-state resistance of 10Ohm with channel-to-channel matching of 2Ohm. The part is packaged in 8-VSSOP surface mount configuration and is RoHS3 compliant with MSL Level 1 rating.

The SN74LVC2G66DCUT has reached Last Time Buy status, indicating end-of-life production. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for new production runs and long-term support.

Key Parameters

Parameter	Value
Switch Circuit Type	SPST - NO
Number of Circuits	2
Multiplexer/Demultiplexer Configuration	1:1
On-State Resistance (Max)	10Ohm
Channel-to-Channel Matching (ΔRon)	2Ohm (Max)
Supply Voltage Range (V+)	1.65V ~ 5.5V
Switch Time (Ton, Toff) (Max)	3.9ns, 6.3ns
-3dB Bandwidth	300MHz
Channel Capacitance (CS(off), CD(off))	6pF
Current - Leakage (IS(off)) (Max)	100nA
Crosstalk	-58dB @ 1MHz
Operating Temperature Range	-40°C ~ 85°C
Package / Case	8-VFSOP (0.091", 2.30mm Width)
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LVC2G66DCUT is determined by the following critical parameters:

Primary Substitution Criteria:

Switch circuit type: SPST - NO
Number of circuits: 2
Multiplexer/demultiplexer configuration: 1:1
On-state resistance: 10Ohm maximum
Supply voltage compatibility: 1.65V ~ 5.5V range
Package type: 8-VFSOP surface mount
RoHS3 compliance and MSL Level 1 rating

Secondary Compatibility Factors:

Switch timing characteristics (Ton, Toff)
Bandwidth performance (-3dB)
Leakage current specifications
Operating temperature range overlap
Channel capacitance and crosstalk performance

Substitute parts are grouped into three categories based on their relationship to the main part:

Parametric Equivalent: SN74LVC2G66DCUR shares identical electrical specifications and differs only in packaging format (Cut Tape & Digi-Reel® versus Tape & Reel).

Direct Manufacturer Alternatives: NL7WB66USG (onsemi) and FSA1259AK8X (onsemi) provide functional equivalence with variations in on-state resistance, bandwidth, and leakage characteristics.

Manufacturer Recommended Alternatives: 74LVC2G66DC,125 (Nexperia), 74LVCV2G66DC,125 (Nexperia), and TC4W66FU,LF (Toshiba) offer enhanced performance specifications or extended operating ranges while maintaining core switching functionality.

Parameter Comparison

Parameter	SN74LVC2G66DCUT	SN74LVC2G66DCUR	NL7WB66USG	74LVC2G66DC,125	74LVCV2G66DC,125	FSA1259AK8X	TC4W66FU,LF
Manufacturer	Texas Instruments	Texas Instruments	onsemi	Nexperia USA Inc.	Nexperia USA Inc.	onsemi	Toshiba Semiconductor
Product Status	Last Time Buy	Active	Obsolete	Active	Active	Obsolete	Active
Switch Circuit	SPST - NO	SPST - NO	SPST - NO	SPST - NO	SPST - NO	SPST - NO	SPST - NO
Number of Circuits	2	2	2	2	2	2	2
On-State Resistance (Max)	10Ohm	10Ohm	10Ohm	10Ohm	10Ohm	850mOhm	160Ohm
Channel-to-Channel Matching (ΔRon)	2Ohm (Max)	2Ohm (Max)	15Ohm	-	-	50mOhm	4Ohm
Supply Voltage (V+)	1.65V ~ 5.5V	1.65V ~ 5.5V	1.65V ~ 5.5V	1.65V ~ 5.5V	2.3V ~ 5.5V	1.65V ~ 5.5V	3V ~ 18V
Switch Time Ton (Max)	3.9ns	3.9ns	3.9ns	3.9ns	5ns	7.5ns	-
Switch Time Toff (Max)	6.3ns	6.3ns	6.3ns	5ns	9ns	17ns	-
-3dB Bandwidth	300MHz	300MHz	186MHz	500MHz	210MHz	240MHz	30MHz
Channel Capacitance (CS(off), CD(off))	6pF	6pF	10pF, 10pF	5pF	8pF	21pF	0.5pF, 5pF
Current - Leakage (IS(off)) (Max)	100nA	100nA	1nA	5µA	10µA	10nA	100nA
Crosstalk	-58dB @ 1MHz	-58dB @ 1MHz	-	-56dB @ 1MHz	-55dB @ 1MHz	-73dB @ 1MHz	-50dB @ 1MHz
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	-55°C ~ 125°C	-40°C ~ 125°C	-40°C ~ 125°C	-40°C ~ 85°C	-40°C ~ 85°C
Package / Case	8-VFSOP	8-VFSOP	8-VFSOP	8-VFSOP	8-VFSOP	8-VFSOP	8-TSSOP, 8-MSOP
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
MSL Rating	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

Direct Replacement (Highest Compatibility):

SN74LVC2G66DCUR is the optimal direct replacement for SN74LVC2G66DCUT. Both parts are manufactured by Texas Instruments, share identical electrical specifications, and differ only in packaging format. The DCUR variant is currently in Active production status with significantly higher inventory availability (17,400 units versus 4,300 units), making it the preferred choice for new designs and production continuity.

Active Production Alternatives:

74LVC2G66DC,125 (Nexperia) and 74LVCV2G66DC,125 (Nexperia) are both in Active production status and provide extended operating temperature ranges (-40°C to 125°C). The 74LVC2G66DC,125 variant offers superior bandwidth performance (500MHz versus 300MHz) and faster switch-off time (5ns versus 6.3ns), making it suitable for higher-frequency applications. The 74LVCV2G66DC,125 variant operates from 2.3V minimum supply voltage and features lower charge injection (0.0035pC), beneficial for low-voltage and precision switching applications.

TC4W66FU,LF (Toshiba) is in Active production with the highest inventory availability (86,753 units). This part operates across an extended supply voltage range (3V to 18V) and is suitable for applications requiring higher voltage operation. However, the significantly higher on-state resistance (160Ohm) and lower bandwidth (30MHz) restrict its use to lower-frequency, higher-impedance switching applications.

Obsolete Parts (Not Recommended for New Designs):

NL7WB66USG (onsemi) and FSA1259AK8X (onsemi) are both marked as Obsolete and should not be selected for new production designs. These parts are retained in the substitute list for reference only in legacy system maintenance scenarios.

Compliance and Certification:

All listed substitute parts maintain RoHS3 compliance and MSL Level 1 rating, ensuring compatibility with modern manufacturing processes and long-term storage requirements.

Frequently Asked Questions (FAQ)

Q: Can SN74LVC2G66DCUR be used as a direct replacement for SN74LVC2G66DCUT?

A: Yes. SN74LVC2G66DCUR is a direct parametric equivalent manufactured by Texas Instruments with identical electrical specifications. The only difference is packaging format: DCUR uses Cut Tape & Digi-Reel® packaging while DCUT uses Tape & Reel packaging. Both are surface mount 8-VSSOP packages with identical pin configurations and electrical performance.

Q: What is the minimum supply voltage requirement for each substitute part?

A: SN74LVC2G66DCUT, SN74LVC2G66DCUR, NL7WB66USG, and FSA1259AK8X all operate from 1.65V minimum. 74LVC2G66DC,125 operates from 1.65V minimum. 74LVCV2G66DC,125 requires 2.3V minimum. TC4W66FU,LF requires 3V minimum. Verify your application's supply voltage range against the selected part's specifications.

Q: Which substitute part offers the best performance for high-frequency applications?

A: 74LVC2G66DC,125 (Nexperia) provides the highest -3dB bandwidth at 500MHz and the fastest switch-off time at 5ns, making it optimal for high-frequency switching applications. SN74LVC2G66DCUR maintains the original 300MHz bandwidth specification.

Q: Are there any package compatibility issues when substituting parts?

A: SN74LVC2G66DCUT, SN74LVC2G66DCUR, NL7WB66USG, 74LVC2G66DC,125, 74LVCV2G66DC,125, and FSA1259AK8X all use the 8-VFSOP surface mount package with identical footprints and pin assignments. TC4W66FU,LF uses an 8-TSSOP or 8-MSOP package, which has a different footprint (0.110" width versus 0.091" width) and requires PCB layout modification.

Q: What is the difference between the Nexperia 74LVC2G66DC,125 and 74LVCV2G66DC,125 variants?

A: Both are Nexperia products in Active production. The 74LVC2G66DC,125 operates from 1.65V to 5.5V with 500MHz bandwidth and 5ns switch-off time. The 74LVCV2G66DC,125 operates from 2.3V to 5.5V with 210MHz bandwidth, 9ns switch-off time, and significantly lower charge injection (0.0035pC). Select 74LVC2G66DC,125 for higher-frequency applications and 74LVCV2G66DC,125 for low-voltage precision switching.

Q: Why are NL7WB66USG and FSA1259AK8X marked as Obsolete?

A: Both parts have reached end-of-life status with manufacturers. While inventory may still be available, these parts should not be selected for new production designs. Use Active production alternatives such as SN74LVC2G66DCUR, 74LVC2G66DC,125, or 74LVCV2G66DC,125 for design continuity and long-term supply assurance.

Q: What is the on-state resistance specification, and why does it matter?

A: On-state resistance (Ron) is the resistance measured across the switch when it is in the closed (conducting) state. SN74LVC2G66DCUT specifies 10Ohm maximum. FSA1259AK8X specifies 850mOhm (lower resistance, better for low-impedance switching), while TC4W66FU,LF specifies 160Ohm (higher resistance, suitable only for high-impedance applications). Verify your circuit's impedance requirements match the selected part's Ron specification.

Q: Can TC4W66FU,LF replace SN74LVC2G66DCUT in all applications?

A: No. While TC4W66FU,LF is in Active production with high inventory, its 160Ohm on-state resistance and 30MHz bandwidth make it unsuitable for most applications designed for the 10Ohm, 300MHz SN74LVC2G66DCUT. Use TC4W66FU,LF only in applications specifically requiring higher supply voltage operation (3V to 18V) and tolerating higher on-state resistance and lower bandwidth.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message