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Texas Instruments SN74CBT3245DBLE
- Part No.:
- SN74CBT3245DBLE
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- -
- Datasheet:
-
SN74CBT3245DBLE.pdf
- Description:
- BUS DRIVER
- Quantity:
- Payment:
- Shipping:
Inventory:15,000
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Product details
Overview
SN74CBT3245DBLE from Texas Instruments is an octal bus switch IC with standard '245-type pinout, 5-Ω on-state resistance, TTL-compatible control inputs, and operation from –40°C to 85°C. It functions as a bidirectional 8-bit analog/digital signal switch in data path isolation and level translation applications, enabling low-delay interconnection between two logic buses.
For engineers reviewing the SN74CBT3245DBLE datasheet, SN74CBT3245DBLE pinout, SN74CBT3245DBLE application, or SN74CBT3245DBLE equivalent, key selection criteria include on-resistance (5–7 Ω), propagation delay (0.25 ns typ), high-impedance isolation during disable, ±128 mA channel current rating, and compatibility with 4–5.5 V supply rails.
Technical Context
The SN74CBT3245DBLE implements a single 8-bit bidirectional analog switch array controlled by one active-low output enable (OE) input. Its BiCMOS process delivers low on-resistance and fast switching with minimal charge injection and capacitive coupling.
It operates without internal latching or direction control-signal flow is fully symmetric between ports A and B. The device supports hot-swap capability due to its overvoltage-tolerant I/O (–0.5 V to 7 V) and input clamp current rating of –50 mA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4 V to 5.5 V - ensures compatibility with 5-V TTL and mixed-voltage system backplanes |
| ron (Typ) | 5 Ω - enables <100 ps additional RC delay into 50-pF loads, preserving signal integrity |
| tpd (Typ) | 0.25 ns - supports >1 GHz data rates in short-reach digital interconnects |
| IO (Max) | ±128 mA per channel - allows direct driving of multiple CMOS inputs or small-signal analog nodes |
| VI/O Range | –0.5 V to 7 V - permits safe operation during power sequencing and voltage-level translation |
| Operating Temp | –40°C to 85°C - qualified for industrial-grade embedded control and communications equipment |
Pinout & Package
SN74CBT3245DBLE is housed in a 20-pin Shrink Small-Outline (DB) package with 0.65-mm lead pitch and 7.2-mm × 4.4-mm body size. Pin 1 is marked via notch or bevel; pin 10 is GND, pin 11 is VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1–A8 | Port A bidirectional I/O | Connects to source-side bus; electrically identical to B pins when switch is enabled |
| B1–B8 | Port B bidirectional I/O | Connects to destination-side bus; no directionality or buffering-pure passive conduction path |
| OE | Active-low output enable | Drives switch ON (low) or OFF (high); TTL-compatible thresholds (VIL ≤ 0.8 V, VIH ≥ 2 V) |
| VCC | Positive supply | Power rail for internal BiCMOS switch control; must be decoupled locally |
| GND | Ground reference | Common return for all I/O and supply currents; critical for noise immunity and ron stability |
Key Features
| Feature | Design Value |
|---|---|
| 5-Ω typical on-state resistance | Minimizes voltage drop and timing skew across all eight channels under 30-mA load conditions |
| 0.25-ns typical propagation delay | Preserves edge fidelity in high-speed address/data bus switching without added jitter or duty-cycle distortion |
| TTL-compatible control inputs | Eliminates need for level-shifting circuitry when driven directly by 5-V microcontrollers or FPGAs |
| –0.5 V to 7 V I/O voltage tolerance | Supports hot-insertion and partial-power-down scenarios without latch-up or damage |
| High-impedance OFF state | Provides >10⁹ Ω isolation between ports A and B, preventing signal contention during bus arbitration |
Applications
| Memory Expansion Interface | PCI/ISA Bus Isolation |
|---|---|
Use Scenario: Adding external SRAM or Flash memory to a microcontroller with limited address/data lines. IC Role / Device Role / Timing Role: Bidirectional bus switch enabling time-multiplexed access to shared memory space without direction control logic. Use Value: Eliminates need for discrete transceivers or direction pins; 5-Ω ron ensures <10 mV drop at 20 mA, preserving logic margins. | Use Scenario: Isolating legacy ISA peripherals from PCI-based host controllers during system boot or configuration. IC Role / Device Role / Timing Role: Signal-path gate that blocks spurious signals during reset or power-up sequencing. Use Value: 0.25-ns tpd prevents timing violations in 8-MHz ISA cycles; high-Z OFF state avoids bus contention. |
| FPGA I/O Expansion | Hot-Swappable Module Interconnect |
Use Scenario: Extending FPGA GPIO count by routing subsets of I/O through configurable switch banks. IC Role / Device Role / Timing Role: Low-latency, bidirectional signal bridge between FPGA bank and peripheral headers. Use Value: TTL-compatible OE allows direct FPGA pin control; 50 pF Cio(OFF) limits crosstalk during inactive states. | Use Scenario: Enabling insertion/removal of daughter cards while main system remains powered. IC Role / Device Role / Timing Role: Safe signal disconnect element that withstands –0.5 V to 7 V transient voltages during mating. Use Value: Input clamp current rating (–50 mA) and overvoltage I/O protect downstream logic from ESD and contact bounce. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBTD3384DBR | 10-bit, dual-supply (VCCA/VCCB), 3.3-V/5-V level translation; higher ron (~7 Ω) | Required when interfacing 3.3-V FPGAs to 5-V peripherals; adds voltage translation capability | Select when mixed-voltage domain bridging is needed; not pin-compatible with SN74CBT3245DBLE |
| QS3245P | Functionally equivalent octal switch; same pinout and ron (5 Ω), but rated only to 70°C ambient | Suitable for commercial-grade systems where extended temperature range is not required | Drop-in replacement in non-industrial environments; verify thermal derating for sustained 128-mA loading |
Compared with SN74CBT3245DBLE, SN74CBTD3384DBR adds level translation but increases complexity and cost, while QS3245P offers identical functionality at lower temperature grade-making it viable only in benign thermal environments.
Availability
SN74CBT3245DBLE is available at Aetrix Electronics and suitable for memory expansion interfaces, PCI/ISA bus isolation, FPGA I/O expansion, and hot-swappable module interconnects requiring stable component supply and long-term industrial temperature support.
Supply support for SN74CBT3245DBLE 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 experience in high-reliability logic and interface solutions.
The SN74CBT3245DBLE belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered for ultra-low-latency, low-resistance signal routing in high-speed digital systems where timing predictability and signal fidelity are critical.
FAQ
What is the maximum continuous current per channel for the SN74CBT3245DBLE?
The SN74CBT3245DBLE supports up to ±128 mA continuous channel current per switch path. This rating is specified under absolute maximum conditions and assumes proper PCB thermal design. In typical operation at 25°C ambient with 5-V supply, the device sustains 64 mA per channel continuously without exceeding junction temperature limits. Always verify board-level heat dissipation when operating near this limit across all eight channels simultaneously in the SN74CBT3245DBLE.
Does the SN74CBT3245DBLE support level translation between different supply voltages?
No, the SN74CBT3245DBLE does not perform active level translation. It is a single-supply (VCC only) bidirectional analog switch with I/O tolerance from –0.5 V to 7 V, allowing safe operation across voltage domains-but both ports A and B must share the same reference ground and operate within the VCC-supplied logic swing. For true 3.3-V-to-5-V translation, consider SN74CBTD3384DBR instead of SN74CBT3245DBLE.
What is the on-state resistance variation across temperature and voltage for the SN74CBT3245DBLE?
The SN74CBT3245DBLE exhibits on-state resistance (ron) of 5–7 Ω over VCC = 4.5 V and TA = –40°C to 85°C, with typical values measured at 5 Ω (VI = 0 V, II = 30 mA) and 10–15 Ω (VI = 2.4 V, II = 15 mA). This variation reflects MOSFET channel behavior: ron rises with increasing input voltage due to reduced effective VGS, and increases slightly at temperature extremes. Designers should use the 7-Ω max value for worst-case voltage-drop calculations in the SN74CBT3245DBLE.
Can the SN74CBT3245DBLE be used in hot-swap applications?
Yes, the SN74CBT3245DBLE is suitable for hot-swap applications due to its overvoltage-tolerant I/O (–0.5 V to 7 V), –50 mA input clamp current rating, and absence of internal ESD protection diodes to VCC or GND that could cause backfeeding. When inserted into a live backplane, the high-impedance OFF state (enabled by holding OE high) prevents current surges, and the robust input structure absorbs contact bounce transients. This behavior is explicitly validated in the SN74CBT3245DBLE datasheet under absolute maximum ratings.
Is the SN74CBT3245DBLE pin-compatible with standard 74-series '245 devices?
Yes, the SN74CBT3245DBLE uses the standard '245-type pinout: A1–A8 on pins 1–8, GND on pin 10, VCC on pin 11, OE on pin 19, and B1–B8 on pins 12–19 (with pin 20 unused/NC). This matches the physical layout of SN74LS245, SN74HC245, and other octal transceivers-though functionally it is a passive switch, not a 3-state buffer. No PCB redesign is needed when replacing legacy '245s with SN74CBT3245DBLE in bus isolation roles.
SN74CBT3245DBLE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- -
- Circuit:
- -
- Independent Circuits:
- -
- Current - Output High, Low:
- -
- Voltage Supply Source:
- -
- Voltage - Supply:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SN74CBT3245DBLE FAQ
1.How can I place an order for SN74CBT3245DBLE through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CBT3245DBLE 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 SN74CBT3245DBLE reliable?
The price and inventory of SN74CBT3245DBLE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CBT3245DBLE is usually 5 days.
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SN74CBT3245DBLE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CBT3245DBLE 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 SN74CBT3245DBLE?
For technical support, including SN74CBT3245DBLE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CBT3245DBLE requirements.
6.How does Aetrix verify that SN74CBT3245DBLE is sourced from the original manufacturer or authorized distributors?
All SN74CBT3245DBLE 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 SN74CBT3245DBLE meets industry standards.
7.What is the process for return or replacement of SN74CBT3245DBLE?
All SN74CBT3245DBLE units undergo pre-shipment inspection (PSI). If there is an issue with SN74CBT3245DBLE, 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 SN74CBT3245DBLE part is unused and in its original packaging.
Return procedure for SN74CBT3245DBLE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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