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Home > Products > Integrated Circuits (ICs) > Logic > Signal Switches, Multiplexers, Decoders

Texas Instruments 74CBT1G125DCKRG4

Name: 74CBT1G125DCKRG4
Brand: Texas Instruments
SKU: 74CBT1G125DCKRG4
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 74CBT1G125DCKRG4

Manufacturer:: Texas Instruments

Category:: Signal Switches, Multiplexers, Decoders

Package:: 5-TSSOP, SC-70-5, SOT-353

Datasheet:: 74CBT1G125DCKRG4.pdf

Description:: IC BUS SWITCH 1 X 1:1 SC70-5

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Product details

Overview

74CBT1G125DCKRG4 from Texas Instruments is a single-channel FET bus switch optimized for high-speed digital signal routing in 3.3-V and 5-V systems. It features 5-Ω on-state resistance, TTL-compatible OE control input, and bidirectional signal pass-through between A and B ports when enabled. Used in data path isolation, level translation, and hot-swap I/O buffering applications.

For engineers reviewing the 74CBT1G125DCKRG4 datasheet, 74CBT1G125DCKRG4 pinout, 74CBT1G125DCKRG4 application, or 74CBT1G125DCKRG4 equivalent, key selection criteria include on-resistance consistency across V_CC = 4–5.5 V, sub-1 ns propagation delay at 50-pF load, ±128-mA continuous channel current rating, and SC-70 (DCK) package thermal performance (θ_JA = 252°C/W).

Technical Context

This device implements a single NMOS transmission gate with no internal pull-ups or level-shifting circuitry - signal integrity relies on external biasing and termination. The OE input directly gates the FET channel; low OE enables conduction, high OE isolates A and B ports with <4 pF off-capacitance.

It operates within –40°C to 85°C ambient, supports supply voltages from 4 V to 5.5 V, and meets JESD 17 latch-up immunity (>250 mA) and JESD 22 ESD ratings (2000-V HBM, 200-V MM). No internal voltage regulation or slew-rate control is present - switching behavior follows passive FET characteristics.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CC Range	4 V to 5.5 V - ensures compatibility with both 3.3-V logic domains (with margin) and 5-V legacy buses
r_ON (Typ)	5 Ω at V_CC = 4.5 V, I_I = 30 mA - enables minimal voltage drop (<150 mV) under full-load signal switching
t_pd (Max)	0.35 ns at V_CC = 4 V, C_L = 50 pF - supports >1 GHz data rate signal routing without timing degradation
I_O (Cont)	±128 mA - allows direct connection to standard CMOS/TTL loads without external current limiting
C_io(OFF)	4 pF - minimizes capacitive loading and crosstalk when port is disabled in high-density routing
ESD Rating	2000-V HBM - provides robust handling during board assembly and field service without added protection diodes
θ_JA	252°C/W (SC-70) - defines thermal derating limit for sustained 128-mA operation in compact PCB layouts

Pinout & Package

74CBT1G125DCKRG4 uses the SC-70 (DCK) 5-pin surface-mount package (2.47 mm × 2.3 mm × 1.25 mm, 1.1 mm max height), optimized for space-constrained portable and industrial PCBs.

Pin/Terminal	Circuit Role	Design Meaning
1 - OE	Output Enable control input	Active-low logic signal; drives internal FET gate - must be tied to V_CC or GND if unused to prevent floating state
2 - A	Port A signal terminal	Bidirectional I/O node; connects to upstream logic or bus segment; no internal termination
3 - GND	Power ground reference	Return path for all internal FET body ties and substrate bias - requires low-inductance PCB connection
4 - V_CC	Positive supply rail	Supplies gate drive and channel bias; decoupling capacitor (0.1 µF) required within 3 mm of pin
5 - B	Port B signal terminal	Bidirectional I/O node; electrically identical to A - supports true analog/digital signal pass-through

Key Features

Feature	Design Value
5-Ω typical on-resistance	Ensures <150 mV voltage drop at 30 mA, preserving logic high/low margins across routed signals
TTL-compatible OE input	Accepts 0.8 V / 2.0 V thresholds - eliminates need for level translators when driven by legacy 5-V controllers
2000-V HBM ESD protection	Reduces risk of field failure in unshielded interfaces like USB peripheral ports or test jigs
Sub-1 ns propagation delay	Maintains signal edge fidelity for DDR clock enable paths and high-speed serial control lines
4 pF off-state capacitance	Prevents signal coupling between adjacent traces in dense FPGA I/O banks or memory subsystems

Applications

PCI Express Slot Isolation	USB 2.0 Data Line Buffering
Use Scenario: Isolating PCIe reference clock or sideband signals during hot-plug insertion to prevent bus contention. IC Role / Device Role / Timing Role: Bidirectional signal switch enabling/disabling clock or PERST# routing between host and add-in card. Use Value: 5-Ω r_ON preserves jitter budget; 4 pF C_io(OFF) avoids skew on 100-MHz REFCLK lines.	Use Scenario: Buffering D+ and D− lines between USB controller and connector to improve ESD robustness and reduce trace crosstalk. IC Role / Device Role / Timing Role: Passive signal conduit with controlled impedance path - no signal regeneration or timing adjustment. Use Value: 2000-V HBM rating absorbs contact discharge; sub-1 ns t_pd prevents bit error in 480-Mbps high-speed mode.
FPGA I/O Bank Multiplexing	Industrial Sensor Interface Switching
Use Scenario: Sharing a single ADC input channel among multiple analog sensors via time-multiplexed routing. IC Role / Device Role / Timing Role: Analog-capable bus switch providing low-distortion signal path with minimal charge injection. Use Value: 5-Ω r_ON limits gain error in 12-bit systems; <4 pF off-capacitance prevents ghosting between sensor channels.	Use Scenario: Selecting between 4–20 mA current-loop transmitters and voltage-output sensors on shared microcontroller ADC inputs. IC Role / Device Role / Timing Role: High-voltage-tolerant (7 V abs max) signal gate enabling safe interface reconfiguration without power cycling. Use Value: –0.5 V to 7 V VI range accommodates sensor output overshoot; ±128 mA rating handles transient fault currents.

PCI Express Slot Isolation

USB 2.0 Data Line Buffering

Use Scenario: Isolating PCIe reference clock or sideband signals during hot-plug insertion to prevent bus contention.

IC Role / Device Role / Timing Role: Bidirectional signal switch enabling/disabling clock or PERST# routing between host and add-in card.

Use Value: 5-Ω r_ON preserves jitter budget; 4 pF C_io(OFF) avoids skew on 100-MHz REFCLK lines.

Use Scenario: Buffering D+ and D− lines between USB controller and connector to improve ESD robustness and reduce trace crosstalk.

IC Role / Device Role / Timing Role: Passive signal conduit with controlled impedance path - no signal regeneration or timing adjustment.

Use Value: 2000-V HBM rating absorbs contact discharge; sub-1 ns t_pd prevents bit error in 480-Mbps high-speed mode.

FPGA I/O Bank Multiplexing

Industrial Sensor Interface Switching

Use Scenario: Sharing a single ADC input channel among multiple analog sensors via time-multiplexed routing.

IC Role / Device Role / Timing Role: Analog-capable bus switch providing low-distortion signal path with minimal charge injection.

Use Value: 5-Ω r_ON limits gain error in 12-bit systems; <4 pF off-capacitance prevents ghosting between sensor channels.

Use Scenario: Selecting between 4–20 mA current-loop transmitters and voltage-output sensors on shared microcontroller ADC inputs.

IC Role / Device Role / Timing Role: High-voltage-tolerant (7 V abs max) signal gate enabling safe interface reconfiguration without power cycling.

Use Value: –0.5 V to 7 V VI range accommodates sensor output overshoot; ±128 mA rating handles transient fault currents.

Equivalent & Alternatives

The following parts are listed as comparable options for similar FET bus switch applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74CBT1G125DCKR	No G4 suffix; same electrical specs, identical SC-70 package, RoHS-compliant NIPDAU finish	No functional difference; differs only in TI's internal assembly/test site marking (SM3 vs SMU)	Select 74CBT1G125DCKRG4 for traceability to TI's G4-qualified production line with extended MSL-1 reflow profile.
74LVC1G3157DPWR	Lower r_ON (3.5 Ω typ), dual SPDT configuration, 1.65–5.5 V V_CC, higher C_io(OFF) (6.5 pF)	Supports dual independent switching paths but occupies larger SOT-23-6 footprint; less suitable for ultra-dense routing	Choose 74LVC1G3157DPWR only when dual-path routing or wider V_CC range is required - not a pin-compatible replacement.

Compared with SN74CBT1G125DCKR, the 74CBT1G125DCKRG4 offers identical switching performance and thermal behavior but includes TI's G4 process qualification for enhanced long-term reliability in automotive-adjacent industrial deployments; versus 74LVC1G3157DPWR, it trades dual-channel flexibility for smaller size, lower off-capacitance, and tighter r_ON tolerance at 5 V.

Availability

74CBT1G125DCKRG4 is available at Aetrix Electronics and suitable for PCI Express slot isolation, USB 2.0 data line buffering, FPGA I/O bank multiplexing, and industrial sensor interface switching requiring stable component supply across extended temperature ranges and high-volume production cycles.

Supply support for 74CBT1G125DCKRG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with over 90 years of innovation in high-reliability IC design and manufacturing.

The SN74CBT family delivers high-speed, low-distortion bus switches for digital signal routing in computing, communications, and industrial control systems - designed specifically for minimal propagation delay and precise on-resistance matching.

FAQ

What is the maximum operating voltage for the 74CBT1G125DCKRG4?

The 74CBT1G125DCKRG4 supports a supply voltage range of 4 V to 5.5 V under recommended conditions, with absolute maximum ratings extending to –0.5 V to 7 V on both V_CC and I/O pins. Exceeding 5.5 V during normal operation risks parametric shift or accelerated wear-out, though short-duration transients up to 7 V are survivable per absolute max limits.

Does the 74CBT1G125DCKRG4 support bidirectional signal flow?

Yes, the 74CBT1G125DCKRG4 is fully bidirectional: signal paths between A and B ports are symmetric with identical on-resistance (5–7 Ω), capacitance (4 pF off), and timing (0.25–0.35 ns t_pd). No direction pin or internal biasing is required - signal direction is determined solely by external source/sink configuration.

Can the 74CBT1G125DCKRG4 be used with 3.3-V logic systems?

Yes, the 74CBT1G125DCKRG4 functions reliably with 3.3-V logic when V_CC = 4 V minimum is maintained - its TTL-compatible OE input accepts 0.8 V (V_IL) and 2.0 V (V_IH) thresholds, allowing direct drive from 3.3-V microcontrollers without level shifters, provided V_CC is set to ≥4 V for guaranteed r_ON and timing performance.

What is the thermal resistance (θ_JA) of the 74CBT1G125DCKRG4 in its SC-70 package?

The 74CBT1G125DCKRG4 in the SC-70 (DCK) package has a specified junction-to-ambient thermal resistance (θ_JA) of 252°C/W under JEDEC JESD 51-7 conditions. This value assumes a standard 2-layer PCB with 1-in² copper pour; actual thermal performance improves with internal copper planes or thermal vias beneath the exposed pad area.

Is the 74CBT1G125DCKRG4 pin-compatible with other members of the SN74CBT1G125 family?

Yes, the 74CBT1G125DCKRG4 shares identical pinout (OE, A, GND, V_CC, B) and electrical behavior with all SC-70 variants including SN74CBT1G125DCKR and SN74CBT1G125DCKT. Differences are limited to packaging quantity, reel markings, and internal TI assembly codes - no PCB layout changes are needed when substituting within the DCK package group.

74CBT1G125DCKRG4 Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: 74CBT

Package/Case:: 5-TSSOP, SC-70-5, SOT-353

Packaging:: Tape & Reel (TR)

Product Status:: Discontinued at Digi-Key

Type:: Bus Switch

Circuit:: 1 x 1:1

Independent Circuits:: 1

Current - Output High, Low:: -

Voltage Supply Source:: Single Supply

Voltage - Supply:: 4V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SC-70-5

74CBT1G125DCKRG4 FAQ

1.How can I place an order for 74CBT1G125DCKRG4 through Aetrix?

Please submit a Request for Quotation (RFQ) for 74CBT1G125DCKRG4 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 74CBT1G125DCKRG4 reliable?

The price and inventory of 74CBT1G125DCKRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74CBT1G125DCKRG4 is usually 5 days.

3.What payment methods are accepted for 74CBT1G125DCKRG4?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74CBT1G125DCKRG4 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74CBT1G125DCKRG4?

74CBT1G125DCKRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74CBT1G125DCKRG4 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 74CBT1G125DCKRG4?

For technical support, including 74CBT1G125DCKRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74CBT1G125DCKRG4 requirements.

6.How does Aetrix verify that 74CBT1G125DCKRG4 is sourced from the original manufacturer or authorized distributors?

All 74CBT1G125DCKRG4 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 74CBT1G125DCKRG4 meets industry standards.

7.What is the process for return or replacement of 74CBT1G125DCKRG4?

All 74CBT1G125DCKRG4 units undergo pre-shipment inspection (PSI). If there is an issue with 74CBT1G125DCKRG4, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 74CBT1G125DCKRG4 part is unused and in its original packaging.

Return procedure for 74CBT1G125DCKRG4:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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