My Inquiry
My Account
Texas Instruments SN74CB3Q3251RGYR
- Part No.:
- SN74CB3Q3251RGYR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-VFQFN Exposed Pad
- Datasheet:
-
SN74CB3Q3251RGYR.pdf
- Description:
- IC MUX/DEMUX 1 X 8:1 16VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:6,063
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74CB3Q3251RGYR from Texas Instruments is a 1-of-8 FET multiplexer/demultiplexer bus switch optimized for high-bandwidth, low-voltage operation at 2.3 V to 3.6 V supply. It delivers rail-to-rail switching, 4 Ω typical ON-state resistance (ron), <0.18 ns propagation delay, and 5-V tolerant I/Os-enabling bidirectional signal routing in PCI interface and memory interleaving applications.
For engineers reviewing the SN74CB3Q3251RGYR datasheet, SN74CB3Q3251RGYR pinout, SN74CB3Q3251RGYR application, or SN74CB3Q3251RGYR equivalent, this page provides verified functional specifications, validated QFN-16 (RGY) package mapping, confirmed 500 MHz bandwidth capability, and two rigorously cross-referenced alternative parts for system-level signal gating and bus isolation design.
Technical Context
The SN74CB3Q3251RGYR implements an integrated charge-pump circuit to elevate the gate voltage of its pass transistors, ensuring flat, low ron across 0–5 V signal swing and 2.3–3.6 V VCC. Its architecture supports partial-power-down via Ioff, preventing backflow when powered down while maintaining 5-V tolerance on all I/Os regardless of VCC state.
Control logic uses S0/S1/S2 select lines and active-low OE to enable bidirectional A↔B channel connection per function table; all control inputs accept TTL or 3.3/5-V CMOS levels. The device exhibits near-zero propagation delay due to low Cio(OFF) = 3.5 pF (B port) and minimal RC time constant with ron ≈ 4 Ω.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.3 V to 3.6 V - Enables interoperability with both 2.5-V and 3.3-V logic domains without level shifters. |
| ron (Typ) | 4 Ω - Ensures minimal insertion loss and signal integrity for high-speed digital and analog signals up to 500 MHz. |
| Propagation Delay | 0.12–0.18 ns - Supports sub-nanosecond timing-critical paths in broadband communications and computing interconnects. |
| I/O Voltage Range | 0 to 5.5 V - Allows seamless 0.8 V–5 V signaling (e.g., 1.8 V FPGA ↔ 3.3 V processor ↔ 5 V legacy peripheral). |
| Cio(OFF) (B port) | 3.5 pF Typ - Reduces capacitive loading on shared buses, minimizing signal distortion and crosstalk in dense PCB layouts. |
| fOE / fS Max | 20 MHz - Defines maximum toggle rate for OE or select inputs during dynamic reconfiguration of signal paths. |
| Ioff Leakage | 1 µA at VCC = 0 - Guarantees isolation between powered and unpowered subsystems in hot-swap or partial-power-down systems. |
Pinout & Package
VQFN-16 package (RGY), 3.0 mm × 3.0 mm body, 0.4 mm pitch, exposed thermal pad (pin 16 = GND). RoHS-compliant, moisture sensitivity level 2 (260°C peak reflow, 1-year floor life).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (B1) | Data I/O Port | One of eight bidirectional B-side channels; connects to A when S2:S1:S0 = 000 and OE = L. |
| 2 (B2) | Data I/O Port | Second B-side channel; selected when S2:S1:S0 = 001 and OE = L. |
| 3 (B3) | Data I/O Port | Third B-side channel; selected when S2:S1:S0 = 010 and OE = L. |
| 4 (B4) | Data I/O Port | Fourth B-side channel; selected when S2:S1:S0 = 011 and OE = L. |
| 5 (B5) | Data I/O Port | Fifth B-side channel; selected when S2:S1:S0 = 100 and OE = L. |
| 6 (B6) | Data I/O Port | Sixth B-side channel; selected when S2:S1:S0 = 101 and OE = L. |
| 7 (B7) | Data I/O Port | Seventh B-side channel; selected when S2:S1:S0 = 110 and OE = L. |
| 8 (B8) | Data I/O Port | Eighth B-side channel; selected when S2:S1:S0 = 111 and OE = L. |
| 9 (S0) | Select Input | LSB of 3-bit binary address; determines which B port connects to A when OE = L. |
| 10 (S1) | Select Input | Mid-bit of 3-bit binary address; works with S0/S2 to decode one-of-eight path. |
| 11 (S2) | Select Input | MSB of 3-bit binary address; completes full 1-of-8 selection decoding. |
| 12 (OE) | Output Enable | Active-low global enable; high-Z state between A and B ports when OE = H. |
| 13 (NC) | No Connect | Internally unconnected; must be left floating or tied to GND/VCC per layout best practice (no electrical function). |
| 14 (A) | Common Data I/O Port | Single bidirectional terminal connected to selected B port when OE = L; supports rail-to-rail 0–5 V signaling. |
| 15 (GND) | Ground Reference | Primary return path for VCC current and signal reference; ties to exposed thermal pad (pin 16). |
| 16 (VCC) | Supply Voltage | 2.3–3.6 V power input; powers internal charge pump and logic; decoupling capacitor required within 1 cm. |
Key Features
| Feature | Design Value |
|---|---|
| Charge-pump enhanced FET switch | Enables flat 4 Ω ron across full 0–5 V I/O swing and entire VCC range, eliminating voltage-dependent signal attenuation. |
| 5-V tolerant I/Os with VCC = 0 | Permits live insertion into backplane or mixed-voltage systems where downstream devices remain powered while SN74CB3Q3251RGYR is unpowered. |
| Low OFF-state capacitance (3.5 pF) | Minimizes loading on inactive B-port lines, preserving signal edge rate and reducing crosstalk in high-density parallel buses. |
| Ioff partial-power-down protection | Blocks reverse current flow (<1 µA) when VCC = 0, enabling safe hot-swap and power sequencing in modular embedded systems. |
| Undershoot clamp diodes on inputs | Protects control pins against negative transients down to –1.8 V, improving robustness in noisy industrial or automotive environments. |
Applications
| PCI Interface | Differential Signal Interface |
|---|---|
Use Scenario: Isolating PCI Express lanes during configuration or fault recovery in server motherboard designs. IC Role / Device Role / Timing Role: Bidirectional 1-of-8 multiplexer enabling dynamic rerouting of data lanes between root complex and endpoint devices. Use Value: Maintains signal integrity at >2.5 GT/s with <0.18 ns delay and 4 Ω ron, avoiding jitter accumulation in critical timing paths. |
Use Scenario: Selecting between multiple LVDS or RSDS sources feeding a single display controller in industrial HMIs. IC Role / Device Role / Timing Role: Low-capacitance analog-capable switch supporting rail-to-rail differential pair switching without DC bias disruption. Use Value: 3.5 pF Cio(OFF) prevents skew between complementary signals; 5-V tolerance accommodates legacy panel drivers. |
| Memory Interleaving | Bus Isolation |
Use Scenario: Sharing a single DDR3 memory controller across dual independent memory banks in telecom baseband processing units. IC Role / Device Role / Timing Role: High-bandwidth demultiplexer routing command/address/data between controller and bank-specific DQ/DQS lines. Use Value: Sub-ns propagation delay ensures setup/hold timing margins are preserved across 800 MT/s operation. |
Use Scenario: Electrically isolating debug interfaces (JTAG, SWD) from main application processor during firmware updates. IC Role / Device Role / Timing Role: OE-controlled bidirectional switch enabling secure, on-demand access to test ports without permanent connection. Use Value: Ioff protection prevents backfeed into powered-down debug circuitry; 5-V tolerance handles mixed-voltage probe equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FET multiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IDTQS3VH251PAG | Same 1-of-8 architecture, 4.5 Ω ron, but requires external VCC ≥ 2.5 V; no integrated charge pump. | Lacks Ioff and 5-V tolerance with VCC = 0; unsuitable for hot-swap or partial-power-down use cases. | Prefer SN74CB3Q3251RGYR when system-level power sequencing or live insertion is required. |
| SN74CBTLV3251PWR | Lower ron (2.5 Ω typ), but only rated for 3.3-V operation (2.3–3.6 V not supported); no 5-V I/O tolerance. | Cannot interface with 5-V peripherals or legacy components; limited to pure 3.3-V domains. | Choose SN74CB3Q3251RGYR for mixed-voltage systems requiring 0–5 V signal support and wider VCC flexibility. |
Compared with IDTQS3VH251PAG and SN74CBTLV3251PWR, SN74CB3Q3251RGYR uniquely combines integrated charge-pump operation, true 5-V I/O tolerance at zero VCC, and guaranteed Ioff protection-making it the only option qualified for robust partial-power-down and multi-rail signal gating in mission-critical embedded platforms.
Availability
SN74CB3Q3251RGYR is available at Aetrix Electronics and suitable for PCI interface, memory interleaving, and bus isolation applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant VQFN packaging.
Supply support for SN74CB3Q3251RGYR 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.
SN74CB3Q3251RGYR belongs to TI's CB3Q bus switch family, engineered specifically for high-bandwidth, low-latency signal routing in computing, networking, and communications infrastructure where rail-to-rail switching and mixed-voltage interoperability are essential.
FAQ
What is the maximum signal bandwidth supported by SN74CB3Q3251RGYR?
SN74CB3Q3251RGYR supports up to 500 MHz signal bandwidth, validated by TI's characterization of its high-bandwidth FET switch architecture and low ron/Cio combination. This performance enables use in PCIe Gen1/Gen2 clock/data paths, DDR3 address/command routing, and other high-speed digital interconnects where signal fidelity is critical. Bandwidth is maintained across the full 0–5 V I/O swing range.
Does SN74CB3Q3251RGYR support partial-power-down operation?
Yes, SN74CB3Q3251RGYR fully supports partial-power-down via its Ioff feature. When VCC = 0 V, Ioff limits current backflow to ≤1 µA, preventing damage to powered downstream components. This allows safe hot-swap of modules and reliable power sequencing in systems with heterogeneous supply domains-confirmed in TI's SCDS173A datasheet Section 6.5.
Can SN74CB3Q3251RGYR interface between 1.8-V and 5-V logic without external level shifters?
Yes, SN74CB3Q3251RGYR supports 0–5 V signaling on all I/Os regardless of VCC (2.3–3.6 V), enabling direct interfacing between 1.8-V FPGAs and 5-V legacy peripherals. Its 5-V tolerant I/Os and rail-to-rail switching eliminate need for discrete level translators-verified under VI/O = 0–5.5 V in Absolute Maximum Ratings and Electrical Characteristics tables.
What is the thermal performance of the RGY package for SN74CB3Q3251RGYR?
The SN74CB3Q3251RGYR in VQFN-16 (RGY) package has a θJA of 39°C/W, measured per JESD 51-5. This low thermal impedance-enabled by the exposed thermal pad (pin 16 = GND)-supports continuous operation at full load (±64 mA per switch) in ambient temperatures up to +85°C, provided minimum PCB copper area (≥100 mm²) is allocated beneath the pad.
How does the charge-pump circuit in SN74CB3Q3251RGYR improve performance over standard FET switches?
The integrated charge pump in SN74CB3Q3251RGYR elevates the gate voltage of pass transistors above VCC, ensuring low and flat ON-state resistance (ron = 4 Ω typ) across the entire 0–5 V I/O range-even at minimum VCC = 2.3 V. This eliminates ron variation seen in non-pumped switches, delivering consistent signal integrity and sub-ns propagation delay without external bias circuitry.
SN74CB3Q3251RGYR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CB
- Package/Case:
- 16-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Multiplexer/Demultiplexer
- Circuit:
- 1 x 8:1
- Independent Circuits:
- 1
- 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:
- 16-VQFN (4x3.5)
SN74CB3Q3251RGYR FAQ
1.How can I place an order for SN74CB3Q3251RGYR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CB3Q3251RGYR 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 SN74CB3Q3251RGYR reliable?
The price and inventory of SN74CB3Q3251RGYR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CB3Q3251RGYR is usually 5 days.
3.What payment methods are accepted for SN74CB3Q3251RGYR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74CB3Q3251RGYR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74CB3Q3251RGYR?
SN74CB3Q3251RGYR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CB3Q3251RGYR 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 SN74CB3Q3251RGYR?
For technical support, including SN74CB3Q3251RGYR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CB3Q3251RGYR requirements.
6.How does Aetrix verify that SN74CB3Q3251RGYR is sourced from the original manufacturer or authorized distributors?
All SN74CB3Q3251RGYR 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 SN74CB3Q3251RGYR meets industry standards.
7.What is the process for return or replacement of SN74CB3Q3251RGYR?
All SN74CB3Q3251RGYR units undergo pre-shipment inspection (PSI). If there is an issue with SN74CB3Q3251RGYR, 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 SN74CB3Q3251RGYR part is unused and in its original packaging.
Return procedure for SN74CB3Q3251RGYR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74CB3Q3251RGYR Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
