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Texas Instruments SN74CBT3126RGYR
- Part No.:
- SN74CBT3126RGYR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 14-VFQFN Exposed Pad
- Datasheet:
-
SN74CBT3126RGYR.pdf
- Description:
- IC BUS SWITCH 1 X 1:1 14VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:44,660
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Product details
Overview
SN74CBT3126RGYR from Texas Instruments is a quadruple FET bus switch IC used for bidirectional signal routing in high-speed digital systems. It features four independent 5-Ω analog switches, TTL-compatible control inputs, latch-up immunity exceeding 250 mA per JESD 17, and operates from 4 V to 5.5 V supply voltage. It is commonly deployed in data path isolation, level translation, and hot-swap I/O buffering applications.
For engineers reviewing the SN74CBT3126RGYR datasheet, SN74CBT3126RGYR pinout, SN74CBT3126RGYR application, or SN74CBT3126RGYR equivalent, key selection considerations include on-state resistance (5–7 Ω), propagation delay (0.25–0.35 ns), thermal performance (θJA = 47°C/W), and VQFN-14 (RGY) package compatibility with high-density PCB layouts.
Technical Context
This device implements four independent NMOS transmission gate switches controlled by active-high OE inputs. Each switch connects A and B ports bidirectionally when enabled, presenting low on-resistance and minimal capacitive loading (Cio(OFF) = 4 pF). The architecture avoids internal latching and supports rail-to-rail analog/digital signal pass-through without directionality constraints.
Designed for 3.3-V/5-V mixed-voltage systems, it accepts TTL-level control signals (VIL ≤ 0.8 V, VIH ≥ 2 V) while maintaining CMOS-compatible input leakage (±1 μA) and ultra-low quiescent supply current (3 μA). Its ESD robustness (latch-up >250 mA) and wide operating temperature range (−40°C to +85°C) support industrial-grade reliability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage (VCC) | 4 V to 5.5 V - Enables direct interface with 5-V logic and tolerance to supply droop during transient load conditions. |
| On-State Resistance (ron) | 5–7 Ω at VCC = 4.5 V - Ensures minimal signal attenuation and voltage drop (<35 mV at 5 mA) across switched paths. |
| Propagation Delay (tpd) | 0.25 ns (VCC = 5 V) - Supports >1 GHz data rates in point-to-point or fanout-limited bus architectures. |
| Off-State Capacitance (Cio(OFF)) | 4 pF - Reduces crosstalk and maintains signal integrity in high-frequency routing between ASICs, FPGAs, or memory interfaces. |
| Input Leakage Current (II) | ±1 μA - Minimizes power loss and prevents unintended biasing in floating or high-impedance control lines. |
| Thermal Resistance (θJA) | 47°C/W (RGY package) - Allows sustained operation at full load without external heatsinking in compact industrial modules. |
| Latch-Up Immunity | >250 mA per JESD 17 - Guarantees robustness against transient overcurrent events in hot-plug or shared-bus environments. |
Pinout & Package
VQFN-14 (RGY) package: 3.5 mm × 3.5 mm body, 0.5 mm pitch, exposed thermal pad, 1 mm max height. Requires soldering of thermal pad for optimal thermal and mechanical performance per SLUA271.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE, 2OE, 3OE, 4OE | Active-high output-enable control | Each independently enables/disables its associated A↔B switch; tie low via pulldown resistor during power-up/down to guarantee high-Z state. |
| 1A–4A, 1B–4B | Bidirectional signal terminals | Pass analog or digital signals in either direction with no polarity constraint; symmetric ron and Cio ensure channel reciprocity. |
| VCC | Positive supply | Supplies all four switches and control logic; decoupling capacitor required within 1 cm of pin for stable high-speed switching. |
| GND | Ground reference | Common return for signal and supply paths; must be connected to low-impedance PCB ground plane adjacent to thermal pad. |
Key Features
| Feature | Design Value |
|---|---|
| 5-Ω analog switch | Enables low-loss signal routing for clock, data, and address lines up to 100 MHz without waveform distortion. |
| TTL-compatible inputs | Accepts standard 3.3-V or 5-V logic thresholds without level-shifter circuitry, simplifying integration with legacy controllers. |
| Independent channel control | Permits selective isolation of individual data lanes-e.g., disable only faulty I²C lines while maintaining others active. |
| High off-isolation (4 pF) | Minimizes capacitive coupling between adjacent channels, critical for noise-sensitive mixed-signal subsystems. |
| Power-up/down high-Z guarantee | Ensures no bus contention during sequencing; achieved by grounding OE pins via external pulldown resistors. |
Applications
| PCI Express Lane Isolation | FPGA I/O Expansion |
|---|---|
Use Scenario: Isolating PCIe Gen2 x1 lanes during hot-plug insertion to prevent backdrive and protocol corruption. IC Role / Device Role / Timing Role: Bidirectional analog switch placed between host controller and slot connector to break DC continuity while preserving AC-coupled signal path integrity. Use Value: Prevents system reset due to bus contention; enables seamless field-replaceable module upgrades without powering down the main board. |
Use Scenario: Expanding FPGA GPIO count by multiplexing shared peripheral buses (e.g., SPI, UART) across multiple daughterboards. IC Role / Device Role / Timing Role: Signal-routing switch enabling time-shared access to common serial interfaces without tri-state buffer conflicts. Use Value: Reduces FPGA pin count pressure and eliminates need for complex bus arbitration logic in resource-constrained designs. |
| Memory Address Bus Buffering | Industrial Sensor Hub Multiplexing |
Use Scenario: Buffering address lines between microcontroller and parallel NOR flash to reduce capacitive loading and improve timing margin. IC Role / Device Role / Timing Role: Low-ron, low-Cio switch inserted inline to isolate driver from distributed trace capacitance. Use Value: Extends maximum reliable address bus length by 30% and reduces setup/hold violations at 40-MHz read cycles. |
Use Scenario: Sharing a single ADC input among eight analog sensor outputs in programmable logic controller (PLC) I/O modules. IC Role / Device Role / Timing Role: Analog multiplexer providing selectable signal path from sensors to precision ADC front-end. Use Value: Achieves <1 LSB gain error across −40°C to +85°C due to matched ron tracking and sub-pF channel-to-channel crosstalk. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FET bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBTD3384PWR | Octal configuration, higher ron (7–9 Ω), 24-pin TSSOP package | Supports wider data buses (e.g., 8-bit parallel interfaces); less suitable for space-constrained 14-pin layouts | Choose when expanding to octal channels and PCB real estate permits larger footprint. |
| 74LVC1G66GW,125 | Single-channel, 5.5-Ω ron, SC-70-6 package, lower ICC (0.1 μA) | Optimized for ultra-low-power sensor nodes; requires four discrete units to match quad functionality | Prefer for battery-powered edge devices where per-channel enable granularity and standby current dominate design priorities. |
Compared with SN74CBT3126RGYR, SN74CBTD3384PWR offers higher channel density but increases layout area and thermal mass, while 74LVC1G66GW,125 trades integration for extreme low-power operation-neither provides identical pin-compatible replacement, but both serve overlapping signal-routing roles with distinct trade-offs in size, power, and scalability.
Availability
SN74CBT3126RGYR is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded computing applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for SN74CBT3126RGYR 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 components.
The SN74CBT3126RGYR belongs to TI's CBT (Crossbar Bus Transceiver) family, engineered for high-speed, low-distortion signal routing in digital infrastructure, communications equipment, and programmable logic interconnects.
FAQ
What is the maximum continuous current rating per channel of the SN74CBT3126RGYR?
The SN74CBT3126RGYR supports a continuous channel current of 128 mA per switch. This rating ensures safe operation under sustained load conditions typical in buffered address/data bus applications. Exceeding this value risks thermal runaway or parametric shift. Derating is recommended above 70°C ambient per the device's θJA = 47°C/W specification. Always verify current distribution across all four channels in multi-switch configurations.
Does the SN74CBT3126RGYR require external pull-down resistors on OE pins?
Yes, the SN74CBT3126RGYR requires external pulldown resistors on all OE inputs to ensure high-impedance state during power-up or power-down sequences. TI recommends tying OE to GND through a resistor whose minimum value depends on the driving source's current-sourcing capability. Failure to do so may cause undefined switch states and bus contention. This requirement is explicitly stated in the datasheet's "description/ordering information" section.
Can the SN74CBT3126RGYR be used for analog signal switching?
Yes, the SN74CBT3126RGYR supports analog signal switching due to its bidirectional FET architecture, rail-to-rail voltage handling (−0.5 V to 7 V), and low on-state resistance (5–7 Ω). It preserves signal integrity for audio, sensor, or clock signals up to ~100 MHz. However, it lacks guaranteed THD or bandwidth specs-designers must validate linearity and settling behavior in their specific analog path, especially near VCC or GND rails.
What is the meaning of "CU126" marking on the SN74CBT3126RGYR package?
"CU126" is the top-side marking for the SN74CBT3126RGYR, as confirmed in TI's ordering information table and package addendum. It identifies the device as part of the CBT3126 family and distinguishes it from other variants (e.g., SOIC-packaged versions marked "CBT3126"). This marking appears on the VQFN-14 (RGY) package alongside TI logo and date code, and is used for traceability and counterfeit detection in production environments.
Is the thermal pad on the SN74CBT3126RGYR package electrically connected internally?
No, the exposed thermal pad on the SN74CBT3126RGYR (RGY package) is not electrically connected to any internal node-it serves solely for thermal conduction and mechanical anchoring. TI documentation (SLUA271) specifies that the pad must be soldered to a PCB thermal plane but may remain floating or tied to GND based on system grounding strategy. Electrical connection is optional and design-dependent; no internal bond wire links it to VCC or GND.
SN74CBT3126RGYR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CBT
- Package/Case:
- 14-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Bus Switch
- Circuit:
- 1 x 1:1
- Independent Circuits:
- 4
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-VQFN (3.5x3.5)
SN74CBT3126RGYR FAQ
1.How can I place an order for SN74CBT3126RGYR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CBT3126RGYR 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 SN74CBT3126RGYR reliable?
The price and inventory of SN74CBT3126RGYR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CBT3126RGYR is usually 5 days.
3.What payment methods are accepted for SN74CBT3126RGYR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74CBT3126RGYR transactions.
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4.How is shipping managed for SN74CBT3126RGYR?
SN74CBT3126RGYR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CBT3126RGYR 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 SN74CBT3126RGYR?
For technical support, including SN74CBT3126RGYR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CBT3126RGYR requirements.
6.How does Aetrix verify that SN74CBT3126RGYR is sourced from the original manufacturer or authorized distributors?
All SN74CBT3126RGYR 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 SN74CBT3126RGYR meets industry standards.
7.What is the process for return or replacement of SN74CBT3126RGYR?
All SN74CBT3126RGYR units undergo pre-shipment inspection (PSI). If there is an issue with SN74CBT3126RGYR, 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 SN74CBT3126RGYR part is unused and in its original packaging.
Return procedure for SN74CBT3126RGYR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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