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Texas Instruments SN74CBT3125PWR
- Part No.:
- SN74CBT3125PWR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74CBT3125PWR.pdf
- Description:
- IC BUS SWITCH 1 X 1:1 14TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,811
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Product details
Overview
SN74CBT3125PWR from Texas Instruments is a quadruple FET bus switch IC with independent 5-Ω bidirectional analog/digital signal paths, TTL-compatible control inputs, and 4.0–5.5 V supply operation. It enables low-latency (0.25 ns typical tpd) signal routing in high-speed data buses, memory expansion interfaces, and logic-level translation circuits.
For engineers reviewing the SN74CBT3125PWR datasheet, SN74CBT3125PWR pinout, SN74CBT3125PWR application, or SN74CBT3125PWR equivalent, key selection criteria include on-state resistance (5–7 Ω), enable/disable timing (1.6–6 ns), thermal impedance (113°C/W), and TSSOP-14 package compatibility with space-constrained PCB layouts.
Technical Context
This device implements four independent single-pole single-throw (SPST) FET switches controlled by separate OE inputs. Each switch connects A and B ports when OE is low (L), presenting <7 Ω on-resistance and <4 pF off-capacitance - optimized for minimal signal distortion in 3.3 V/5 V mixed-voltage systems.
It uses NMOS pass-gate architecture with no internal level-shifting circuitry, requiring external pull-up resistors on OE pins to ensure high-impedance state during power-up/down. Input clamp current rating (−50 mA) and absolute max VI of −0.5 V to 7 V support robust I/O protection in noisy environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.0 V to 5.5 V - supports direct interface with 3.3 V logic families via 5 V tolerant inputs and ensures stable switching performance across industrial supply tolerances. |
| ron (Typical) | 5 Ω at VCC = 4.5 V - enables <10 mV voltage drop at 64 mA channel current, preserving signal integrity in high-current digital bus applications. |
| tpd (Max) | 0.35 ns at VCC = 4 V - guarantees sub-nanosecond propagation delay for clock distribution, address/data multiplexing, and real-time signal gating. |
| Cio(OFF) | 4 pF - minimizes capacitive loading on disabled channels, critical for maintaining signal rise/fall times in multi-drop bus topologies. |
| ICC (Max) | 3 μA - ultra-low quiescent current reduces system-level power budget impact in always-on or battery-backed subsystems. |
| θJA | 113°C/W - defines thermal derating limit for continuous 128 mA channel current in standard FR-4 PCB layouts with 1 oz copper. |
Pinout & Package
TSSOP-14 (PW) package: 5.0 mm × 4.4 mm × 1.2 mm body, 0.65 mm lead pitch, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1 (unlimited reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 7, 10 (OE) | Output-enable control input | Active-low enable per channel; must be pulled to VCC via external resistor to guarantee high-Z state during power sequencing. |
| 2, 5, 12, 15 (A) | Port A terminal | Bidirectional signal node connected directly to internal FET channel; no polarity or directionality - identical electrical behavior as Port B. |
| 3, 6, 13, 16 (B) | Port B terminal | Second bidirectional signal node; forms low-resistance path with corresponding A pin when OE is low. |
| 8 (GND) | Ground reference | Primary return path for all internal FET sources and bias networks; requires low-inductance connection to system ground plane. |
| 14 (VCC) | Supply voltage | Power rail for all four switch channels and input buffers; bypass capacitor (0.1 μF ceramic) required within 5 mm of this pin. |
Key Features
| Feature | Design Value |
|---|---|
| Quadruple independent switching | Four isolated SPST paths allow concurrent routing of separate data/address/control lines without crosstalk or shared enable constraints. |
| 5 Ω typical on-resistance | Enables <10 mV IR drop at 20 mA, supporting clean signal transmission in 3.3 V LVCMOS and 5 V TTL interfaces without level shifters. |
| TTL-compatible inputs | VIH = 2.0 V / VIL = 0.8 V thresholds ensure reliable recognition of legacy 5 V logic levels while operating from 4 V supply. |
| Low off-capacitance (4 pF) | Reduces signal attenuation and timing skew in high-frequency (>100 MHz) bus applications such as PCI-X stubs or memory data lanes. |
| Sub-nanosecond propagation delay | 0.25 ns typical tpd at 5 V allows integration into nanosecond-critical paths like synchronous FIFO handshaking or clock gating trees. |
Applications
| PCI Express Lane Multiplexing | Memory Expansion Interface |
|---|---|
Use Scenario: Dynamically rerouting PCIe Gen1/Gen2 lanes between two host controllers sharing a common peripheral slot. IC Role / Device Role / Timing Role: Bidirectional signal gate enabling hot-plug lane reassignment without protocol layer intervention. Use Value: 5 Ω ron and 4 pF Cio(OFF) preserve eye diagram integrity up to 2.5 Gbps, meeting PCIe AC timing budgets. | Use Scenario: Adding secondary SRAM or Flash to an MCU with limited address/data pins by time-multiplexing shared bus lines. IC Role / Device Role / Timing Role: Low-latency bus switch isolating memory banks during read/write cycles to prevent contention. Use Value: 0.25 ns tpd eliminates added setup/hold margin penalties, allowing full-speed access to both memory regions. |
| Logic-Level Translation Bridge | Test Access Port (TAP) Signal Routing |
Use Scenario: Interfacing 3.3 V JTAG controller with 5 V boundary-scan devices on same test bus. IC Role / Device Role / Timing Role: Passive voltage-tolerant switch enabling bidirectional signal flow without active translation circuitry. Use Value: VI range (−0.5 V to 7 V) and 5 Ω ron support safe 3.3 V ↔ 5 V signaling without level shifter latency or power domain isolation. | Use Scenario: Sharing a single JTAG debugger across multiple ASICs on a multi-chip module via programmable signal path selection. IC Role / Device Role / Timing Role: Enable-controlled signal router directing TCK/TMS/TDI/TDO to selected DUT under microcontroller supervision. Use Value: Independent OE pins allow per-channel activation, eliminating need for external multiplexer logic and reducing debug interface footprint. |
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 | Higher VCC range (4.5–5.5 V), lower ron (3.5 Ω typ), but requires 5 V supply only - no 4 V operation. | Optimized for 5 V-only systems; unsuitable where 4 V brownout tolerance is required. | Select when maximum speed and lowest on-resistance are prioritized over supply flexibility. |
| 74LVC1G3157DPWR | Single-channel, smaller X2SON-6 package, 3.3 V only (1.65–5.5 V), higher ron (10 Ω typ). | Used in discrete signal routing rather than quad-bus applications; lacks pin-compatible replacement capability. | Choose for space-constrained designs needing one switch, not four - not a drop-in substitute. |
Compared with SN74CBT3125PWR, SN74CBTD3384PWR delivers better ron and speed but sacrifices 4 V operation; 74LVC1G3157DPWR offers miniaturization at the cost of channel count and on-resistance - neither provides pin-to-pin or functional equivalence without layout or firmware changes.
Availability
SN74CBT3125PWR is available at Aetrix Electronics and suitable for high-speed bus multiplexing, memory expansion interfaces, and logic-level translation applications requiring stable component supply across industrial temperature ranges (−40°C to +85°C).
Supply support for SN74CBT3125PWR 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 decades of expertise in high-reliability interface solutions.
The SN74CBT3125PWR belongs to TI's CBT (Crossbar Bus Transceiver) family, engineered for low-latency, low-distortion signal routing in digital systems where timing predictability and voltage-domain bridging are critical.
FAQ
What is the maximum continuous current rating per channel for SN74CBT3125PWR?
The SN74CBT3125PWR supports a continuous channel current of 128 mA per switch. This rating is defined under recommended operating conditions (VCC = 4–5.5 V, TA = −40°C to +85°C) and assumes proper PCB thermal design - including adequate copper pour and via stitching - to maintain junction temperature within safe limits. Exceeding this current may cause thermal shutdown or permanent damage.
Does SN74CBT3125PWR require external pull-up resistors on its OE pins?
Yes, SN74CBT3125PWR requires external pull-up resistors on all OE pins to ensure a defined high-impedance state during power-up and power-down sequences. TI specifies that OE should be tied to VCC through a pull-up resistor, with minimum value determined by the current-sinking capability of the driving source. Typical values range from 4.7 kΩ to 10 kΩ for standard CMOS drivers.
Can SN74CBT3125PWR operate with a 3.3 V supply voltage?
No, SN74CBT3125PWR cannot operate reliably with a 3.3 V supply. Its recommended operating VCC range is strictly 4.0 V to 5.5 V. At 3.3 V, the device fails to meet guaranteed specifications for ron, tpd, and VIH/VIL thresholds. For 3.3 V systems, consider alternatives such as SN74LVC1G3157 or SN74AUC1G66.
What is the thermal impedance (θJA) of SN74CBT3125PWR in its TSSOP-14 package?
The SN74CBT3125PWR in the TSSOP-14 (PW) package has a specified junction-to-ambient thermal impedance (θJA) of 113°C/W. This value is measured per JEDEC JESD51-7 on a standard 4-layer evaluation board with 1 oz copper and 1 in² of 2-oz thermal pad. Real-world θJA will vary based on PCB layout, copper area, and airflow.
Is SN74CBT3125PWR compatible with 5 V tolerant I/O in mixed-voltage systems?
Yes, SN74CBT3125PWR supports 5 V tolerant inputs: its absolute maximum input voltage (VI) is −0.5 V to 7 V, and it operates correctly with 5 V logic signals even when powered from 4.5 V or 5 V. This makes SN74CBT3125PWR suitable for bridging 3.3 V controllers to 5 V peripherals without external level shifters - provided signal swing remains within the VI range and current limits are observed.
SN74CBT3125PWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CBT
- Package/Case:
- 14-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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-TSSOP
SN74CBT3125PWR FAQ
1.How can I place an order for SN74CBT3125PWR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CBT3125PWR 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 SN74CBT3125PWR reliable?
The price and inventory of SN74CBT3125PWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CBT3125PWR is usually 5 days.
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SN74CBT3125PWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CBT3125PWR 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 SN74CBT3125PWR?
For technical support, including SN74CBT3125PWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CBT3125PWR requirements.
6.How does Aetrix verify that SN74CBT3125PWR is sourced from the original manufacturer or authorized distributors?
All SN74CBT3125PWR 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 SN74CBT3125PWR meets industry standards.
7.What is the process for return or replacement of SN74CBT3125PWR?
All SN74CBT3125PWR units undergo pre-shipment inspection (PSI). If there is an issue with SN74CBT3125PWR, 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 SN74CBT3125PWR part is unused and in its original packaging.
Return procedure for SN74CBT3125PWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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