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Texas Instruments SN74CB3Q3125PW
- Part No.:
- SN74CB3Q3125PW
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74CB3Q3125PW.pdf
- Description:
- IC BUS SWITCH 1 X 1:1 14TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:6,281
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Product details
Overview
SN74CB3Q3125PW from Texas Instruments is a quadruple 1-bit FET bus switch optimized for high-bandwidth signal routing in 2.5V/3.3V systems. It delivers rail-to-rail switching (0V–5V with 3.3V VCC), 3Ω typical ON-state resistance, <0.2 ns propagation delay, and 500MHz bandwidth - enabling clean, low-distortion data gating in USB, optical networking, and PBX interfaces.
For engineers reviewing the SN74CB3Q3125PW datasheet, SN74CB3Q3125PW pinout, SN74CB3Q3125PW application, or SN74CB3Q3125PW equivalent, key selection criteria include its 5V-tolerant I/Os during power-up/down, Ioff-enabled partial-power-down capability, bidirectional operation without direction control, and compatibility with 0.8V–5V logic families across –40°C to +85°C.
Technical Context
The SN74CB3Q3125PW integrates four independent FET-based bus switches, each controlled by an active-low OE input. Its charge-pump architecture elevates the gate voltage of the pass transistor to maintain flat, low ron (4Ω typ. over 2.3V–3.6V VCC) and enable rail-to-rail analog/digital signal handling.
Each channel supports bidirectional, near-zero-delay data flow with Cio(OFF) = 4pF typical and 5V-tolerant I/Os regardless of VCC state. Control inputs accept TTL, 3.3V, or 5V CMOS levels, and Ioff blocks current backflow during partial power-down - critical for hot-swap and system-level isolation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.3V to 3.6V - enables interoperability with 2.5V and 3.3V logic domains while supporting mixed-voltage I/O signaling. |
| ron (Typical) | 3Ω at VCC = 3.3V - ensures minimal insertion loss and signal attenuation for high-fidelity analog/digital bus switching. |
| Bandwidth | 500MHz - supports high-speed serial links including USB 2.0 and differential signaling in optical modules. |
| Cio(OFF) | 4pF typical - reduces capacitive loading on source and load circuits, preserving signal integrity and timing margins. |
| tpd | 0.12ns to 0.2ns - enables sub-nanosecond propagation delay for time-critical applications like video-over-fiber and WiMAX baseband. |
| Ioff | 1µA max at VCC = 0V - guarantees robust isolation and prevents back-current damage during partial power-down. |
| ESD Rating | 2000V HBM - meets industrial-grade ESD immunity requirements without external protection circuitry. |
Pinout & Package
TSSOP-14 (PW) package: 5.00mm × 4.40mm body, 0.65mm pitch, surface-mount, lead-free (NIPDAU), MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE, 2OE, 3OE, 4OE | Active-low output enable | Independent per-channel control; drives associated A–B path into high-Z when high. |
| 1A–4A, 1B–4B | Bidirectional data I/O ports | Each pair forms a single-pole, single-throw switch; no directionality required; 5V tolerant. |
| VCC | Power supply | Single 2.3V–3.6V supply powers all four channels and internal charge pump. |
| GND | Ground reference | Common return for all switch paths and logic; decoupling capacitor required at pin. |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail analog/digital switching | Supports 0V–5V signals with 3.3V VCC, enabling seamless interface between legacy 5V peripherals and modern low-voltage SoCs. |
| 5V-tolerant I/Os powered up/down | Allows safe connection to 5V buses even when device is unpowered - eliminates level-shifter requirement in mixed-voltage systems. |
| Charge-pump-enhanced ron | Maintains flat 3–8Ω ON-resistance across full VCC range and signal swing, minimizing harmonic distortion in RF/analog paths. |
| Ioff partial-power-down protection | Prevents destructive back-current flow when VCC = 0V, supporting hot-plug and dynamic power-gating architectures. |
| Low Cio(OFF) & Cin | 4pF OFF-capacitance and 3.5pF input capacitance reduce trace reflections and preserve signal rise/fall times up to 500MHz. |
Applications
| Optical Networking | IP Telephony |
|---|---|
|
Use Scenario: Signal routing in EPON OLT/ONU line cards where multiple SFP+ lanes require dynamic isolation and impedance-matched switching. IC Role / Device Role / Timing Role: Bidirectional bus switch isolating 3.3V PHY interfaces from 5V management buses while maintaining sub-100ps jitter contribution. Use Value: Enables hot-swap-capable optical module slots with zero layout impact from voltage translation or discrete protection components. |
Use Scenario: Audio/data path multiplexing in VoIP desk phones with dual Ethernet ports, USB-C charging, and analog handset interface. IC Role / Device Role / Timing Role: Quad-channel signal gate managing simultaneous USB 2.0, PCM audio, and GPIO lines between baseband processor and peripheral connectors. Use Value: Reduces BOM count by replacing four discrete switches with one 14-pin TSSOP, cutting PCB area by >60% versus discrete solutions. |
| Wireless Infrastructure | Industrial PBX Systems |
|
Use Scenario: Baseband signal conditioning in WiMAX femtocells requiring low-latency switching between ADC/DAC paths and FPGA I/O banks. IC Role / Device Role / Timing Role: High-bandwidth analog switch routing IQ data streams with <0.2ns skew between I/Q pairs under 3.3V operation. Use Value: Eliminates need for external termination resistors due to matched ron and low Cio, simplifying RF front-end calibration. |
Use Scenario: Time-division multiplexing of T1/E1 framing signals and control plane traffic in carrier-grade private branch exchanges. IC Role / Device Role / Timing Role: Four independent 1-bit switches isolating legacy 5V signaling domains from 2.5V DSP cores during firmware updates. Use Value: Ensures uninterrupted call handling during partial system reconfiguration via Ioff-enabled power sequencing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FET bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CB3T3125PW | Higher ron (6Ω typ.), wider VCC range (2.3V–3.6V), same pinout and function - optimized for lower-cost, lower-bandwidth use cases. | Limited to ≤300MHz applications; less suitable for USB 2.0 or optical video transport requiring 500MHz flat response. | Select when cost sensitivity outweighs bandwidth demand and 3Ω ron is not required for signal fidelity. |
| TS3A24159PWR | Dual SPDT configuration (2×2), 0.7Ω ron, 3.3V-only VCC, no Ioff - higher performance per channel but different topology and no partial-power-down support. | Requires redesign for quad 1-bit routing; lacks 5V tolerance during power-down; unsuitable for hot-swap or mixed-voltage isolation. | Choose only if board space allows dual-channel re-architecting and system does not require Ioff or 5V-tolerant off-state isolation. |
Compared with SN74CB3Q3125PW, SN74CB3T3125PW trades bandwidth and ron for cost, while TS3A24159PWR offers lower ron but forces topology change and removes critical Ioff safety - making SN74CB3Q3125PW the optimal balance for 500MHz, mixed-voltage, hot-plug-ready designs.
Availability
SN74CB3Q3125PW is available at Aetrix Electronics and suitable for optical networking, IP telephony, and wireless infrastructure applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for production programs.
Supply support for SN74CB3Q3125PW 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 delivering analog, embedded processing, and connectivity solutions with deep expertise in signal integrity and high-speed interface design.
The SN74CB3Q3125PW belongs to TI's CB3Q family of high-bandwidth FET bus switches, engineered specifically for low-distortion, rail-to-rail signal routing in broadband communications, optical transport, and multi-voltage system interconnects.
FAQ
What is the maximum operating frequency supported by the SN74CB3Q3125PW?
The SN74CB3Q3125PW supports a maximum switching frequency of 20MHz on its OE control inputs and delivers usable signal bandwidth up to 500MHz on its data paths. This 500MHz capability is validated under typical conditions (VCC = 3.3V, 25°C) and enables reliable operation in USB 2.0, video-over-fiber, and EPON applications where signal integrity must be preserved across wide frequency ranges. The SN74CB3Q3125PW achieves this through ultra-low Cio(OFF) and flat ron.
Does the SN74CB3Q3125PW support 5V-tolerant I/Os when unpowered?
Yes, the SN74CB3Q3125PW maintains 5V tolerance on all data I/O pins (A/B ports) regardless of VCC state - including when VCC = 0V. This is enabled by internal clamp diodes and the FET architecture, allowing safe connection to live 5V buses during power-up, power-down, or partial-power-down modes. This feature eliminates external level shifters and protects downstream circuitry, a key advantage confirmed in TI's SCDS143D datasheet Section 7.3.
How does the Ioff feature function in the SN74CB3Q3125PW?
The Ioff circuitry in the SN74CB3Q3125PW actively disables current flow between A and B ports when VCC = 0V, limiting leakage to ≤1µA. This prevents damaging back-current from live buses into unpowered sections of the system - essential for hot-plug, modular chassis, and dynamic power-gating architectures. Unlike passive high-Z states, Ioff is a designed safety mechanism verified per JESD78 Class II latch-up testing, and it operates independently of OE pin state in the SN74CB3Q3125PW.
What is the typical ON-state resistance (ron) of the SN74CB3Q3125PW and how does it vary?
The SN74CB3Q3125PW exhibits a typical ron of 3Ω at VCC = 3.3V and 4Ω at VCC = 2.5V, with flat variation across the full 0V–5V input voltage range. This stability is achieved via an integrated charge pump that boosts the gate drive voltage, ensuring consistent conduction regardless of signal swing. Measured per TI SCDS143D Section 5.5, ron remains ≤8Ω across all recommended operating conditions - directly enabling low-insertion-loss signal routing in the SN74CB3Q3125PW.
Can the SN74CB3Q3125PW be used for analog signal switching?
Yes, the SN74CB3Q3125PW is explicitly qualified for both digital and analog applications, including USB interface, differential signaling, and low-distortion signal gating. Its rail-to-rail operation (0V–5V with 3.3V VCC), low ron flatness, 4pF Cio(OFF), and absence of body diode conduction make it suitable for audio, video, and baseband analog paths. TI's datasheet Section 1 lists "analog applications" as a primary use case, and the SN74CB3Q3125PW's charge-pump architecture avoids the voltage drop and nonlinearity typical of standard MOSFET switches.
SN74CB3Q3125PW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CB
- Package/Case:
- 14-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Bulk
- 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:
- 2.3V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-TSSOP
SN74CB3Q3125PW FAQ
1.How can I place an order for SN74CB3Q3125PW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CB3Q3125PW 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 SN74CB3Q3125PW reliable?
The price and inventory of SN74CB3Q3125PW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CB3Q3125PW is usually 5 days.
3.What payment methods are accepted for SN74CB3Q3125PW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74CB3Q3125PW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74CB3Q3125PW?
SN74CB3Q3125PW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CB3Q3125PW 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 SN74CB3Q3125PW?
For technical support, including SN74CB3Q3125PW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CB3Q3125PW requirements.
6.How does Aetrix verify that SN74CB3Q3125PW is sourced from the original manufacturer or authorized distributors?
All SN74CB3Q3125PW 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 SN74CB3Q3125PW meets industry standards.
7.What is the process for return or replacement of SN74CB3Q3125PW?
All SN74CB3Q3125PW units undergo pre-shipment inspection (PSI). If there is an issue with SN74CB3Q3125PW, 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 SN74CB3Q3125PW part is unused and in its original packaging.
Return procedure for SN74CB3Q3125PW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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