My Inquiry
My Account
Texas Instruments SN74BCT245N
- Part No.:
- SN74BCT245N
- Manufacturer:
- Texas Instruments
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
SN74BCT245N.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,959
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74BCT245N from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in industrial control and memory interface systems. It operates at 4.5–5.5 V, supports 128 mA sink current on B-port outputs, and delivers propagation delays as low as 1 ns (tPLH) under 5 V/50 pF conditions.
For engineers reviewing the SN74BCT245N datasheet, SN74BCT245N pinout, SN74BCT245N application, or SN74BCT245N equivalent, key selection criteria include its 20-pin PDIP package, direction-control (DIR) and output-enable (OE) logic interface, 3-state isolation capability, and compatibility with TTL-level bus driving requirements in legacy embedded systems.
Technical Context
The SN74BCT245N implements dual 8-bit bidirectional data paths controlled by a single DIR input to select A→B or B→A transmission, while OE independently enables or disables all outputs into high-impedance state. Its BCT (Bipolar CMOS Transistor) process delivers TTL-compatible input thresholds and higher drive strength than standard CMOS.
It features separate I/O port electrical characteristics: B-port outputs support up to 64 mA sink (IOL) and –15 mA source (IOH), while A-port outputs deliver 24 mA sink and –3 mA source. Input clamp current is rated at –18 mA, and ESD protection exceeds 2000-V HBM per JESD22-A114-A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - Ensures stable operation across standard 5 V supply rails with ±10% tolerance. |
| B-port IOL | 64 mA - Drives heavy capacitive loads (e.g., long PCB traces or multiple TTL inputs) without signal degradation. |
| tPLH / tPHL | 1 ns / 1.5 ns - Enables high-speed bus arbitration in real-time control systems with sub-ns timing margins. |
| 3-State Enable Time | tPZL = 1.5 ns - Rapid output disable minimizes bus contention during mode switching. |
| Input Thresholds | VIH = 2 V, VIL = 0.8 V - Matches standard TTL logic levels for seamless integration with legacy 74-series components. |
| Thermal Resistance | θJA = 69°C/W - Supports continuous operation at ambient temperatures up to 70°C in natural-convection PDIP layouts. |
Pinout & Package
SN74BCT245N uses a 20-pin plastic dual in-line package (PDIP-N) with 0.3-inch body width and through-hole mounting. Pin 1 is located at the top-left corner adjacent to the notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction Control Input | Low = B-to-A data flow; High = A-to-B data flow - determines real-time bus direction without external logic. |
| 2–9 (A1–A8) | A-Side Data I/O | Bidirectional TTL-compatible ports - connect to microcontroller address/data bus or peripheral interface. |
| 10 (GND) | Ground Reference | Primary return path for all internal logic and output drivers - must be low-inductance connection. |
| 11 (VCC) | Power Supply | +5 V supply for internal biasing and output stage - requires local 0.1 µF ceramic decoupling. |
| 12 (OE) | Output Enable Input | Low = active outputs; High = all outputs in high-Z - enables bus sharing among multiple devices. |
| 13–20 (B1–B8) | B-Side Data I/O | Bidirectional TTL-compatible ports - interface with memory modules, FIFOs, or other system buses. |
Key Features
| Feature | Design Value |
|---|---|
| Octal Bidirectional Bus Interface | Single DIR pin configures full 8-bit data path direction - eliminates need for two separate unidirectional transceivers. |
| 3-State Outputs with Fast Disable | tPZL/tPLZ ≤ 1.5 ns - prevents bus glitches during hot-swap or dynamic reconfiguration. |
| TTL-Compatible Drive Strength | B-port sinks 64 mA - directly drives 10+ standard TTL loads without external buffers. |
| Robust Input Protection | –18 mA input clamp current and 2000-V HBM ESD rating - withstands handling and board-level transients. |
| Wide Operating Temperature | 0°C to 70°C - qualified for commercial-grade industrial control and instrumentation applications. |
Applications
| Industrial PLC Backplane Interface | Legacy Microcontroller Address Latching |
|---|---|
Use Scenario: Isolating CPU address bus from modular I/O expansion slots in programmable logic controllers. IC Role / Device Role / Timing Role: Bidirectional address/data transceiver enabling read/write cycles between master controller and slave modules. Use Value: 3-state outputs prevent bus contention during slot insertion/removal; DIR-controlled direction supports both configuration and runtime data exchange. | Use Scenario: Latching 8-bit address segments from an 8051-family microcontroller to external memory chips. IC Role / Device Role / Timing Role: Level-shifting and buffering address lines between MCU port pins and memory address inputs. Use Value: TTL-compatible VIH/VIL ensures reliable recognition of MCU output states; 64 mA B-port drive handles memory chip input capacitance. |
| Test Equipment Signal Routing Matrix | Automated Test Fixture Bus Arbitration |
Use Scenario: Dynamically routing digital stimulus signals between multiple DUT interfaces in ATE systems. IC Role / Device Role / Timing Role: Reconfigurable bus switch enabling one-to-many or many-to-one signal path selection. Use Value: Sub-2 ns enable/disable times allow precise timing alignment; OE-controlled isolation prevents signal leakage during path reconfiguration. | Use Scenario: Sharing a common test bus among multiple sensor nodes in production line calibration fixtures. IC Role / Device Role / Timing Role: Bidirectional bus isolator coordinating access between microcontroller and distributed sensors. Use Value: DIR-selectable direction supports both command broadcast (MCU→sensors) and response collection (sensors→MCU) on same physical lines. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS245N | Lower drive (24 mA B-port sink), slower speed (tPLH ≈ 10 ns), higher ICC (40 mA typical) | Suitable only for low-frequency (<1 MHz), low-load applications; not drop-in due to timing and drive mismatch | Select when legacy LS logic compatibility is mandatory and speed/load demands are minimal. |
| SN74LVC245APW | 3.3 V only (1.65–3.6 V), 32 mA drive, 3.5 ns tPLH, TSSOP-20 package | Requires level translation for 5 V systems; superior for modern low-voltage designs with space constraints | Choose for new 3.3 V designs where PCB area and power efficiency outweigh 5 V compatibility needs. |
Compared with SN74LS245N and SN74LVC245APW, the SN74BCT245N uniquely balances 5 V TTL interoperability, high drive strength, and nanosecond timing-making it the optimal choice for upgrading legacy 74LS-based backplanes without redesigning power or layout.
Availability
SN74BCT245N is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy microcontroller address latching, and automated test fixture bus arbitration requiring stable component supply and long-term obsolescence management.
Supply support for SN74BCT245N 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 logic solutions with over 50 years of innovation in industrial and automotive electronics.
The SN74BCT245N belongs to TI's BCT logic family, engineered specifically for high-drive, 5 V TTL-compatible bus interfacing in industrial control, test equipment, and legacy system upgrades.
FAQ
What is the maximum operating temperature range for the SN74BCT245N?
The SN74BCT245N is specified for commercial operation from 0°C to +70°C. This range is validated per TI's recommended operating conditions and aligns with its PDIP-N packaging and BCT process thermal characteristics. Operation outside this range may result in timing violations or increased parametric drift. The SN74BCT245N does not support extended or military temperature grades - those require the SN54BCT245 series variants.
Can the SN74BCT245N interface directly with 3.3 V logic systems?
The SN74BCT245N is a 5 V-only device with TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V), so it can accept 3.3 V logic-high signals safely. However, its outputs swing to ~3.4 V (VOH at –3 mA) and ~0.35 V (VOL at 24 mA), which may fall below the VIH requirement of many 3.3 V receivers. Direct connection is not recommended without level-shifting circuitry. The SN74BCT245N is intended for 5 V bus environments.
How does the DIR pin function in the SN74BCT245N?
The DIR pin on the SN74BCT245N controls data flow direction: when DIR = Low, data passes from B-port to A-port; when DIR = High, data flows from A-port to B-port. This single-pin control eliminates the need for discrete direction logic and enables real-time bidirectional communication. DIR is sampled asynchronously - transitions cause immediate path reconfiguration, provided OE is active (Low). The SN74BCT245N does not latch DIR state.
What is the purpose of the OE pin on the SN74BCT245N?
The OE (Output Enable) pin on the SN74BCT245N is an active-low control that places all A- and B-port outputs into high-impedance (3-state) mode when driven High. When OE = Low, outputs are enabled and follow the DIR-selected data path. This allows multiple SN74BCT245N devices to share a common bus without contention. OE timing is critical: tPZL = 1.5 ns ensures fast isolation to prevent bus conflicts during arbitration.
Is the SN74BCT245N RoHS compliant?
Yes, the SN74BCT245N is RoHS compliant, as confirmed in TI's official packaging addendum. It features NiPdAu (nickel-palladium-gold) lead finish and meets EU Directive 2011/65/EU requirements. The ".A" suffix variant (SN74BCT245N.A) shares identical RoHS status and specifications. Compliance documentation, including material declarations and test reports, is available via TI's Quality & Environmental page using the SN74BCT245N part number.
SN74BCT245N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74BCT
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- Transceiver, Non-Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 3mA, 24mA; 15mA, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
SN74BCT245N FAQ
1.How can I place an order for SN74BCT245N through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74BCT245N 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 SN74BCT245N reliable?
The price and inventory of SN74BCT245N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74BCT245N is usually 5 days.
3.What payment methods are accepted for SN74BCT245N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74BCT245N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74BCT245N?
SN74BCT245N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74BCT245N 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 SN74BCT245N?
For technical support, including SN74BCT245N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74BCT245N requirements.
6.How does Aetrix verify that SN74BCT245N is sourced from the original manufacturer or authorized distributors?
All SN74BCT245N 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 SN74BCT245N meets industry standards.
7.What is the process for return or replacement of SN74BCT245N?
All SN74BCT245N units undergo pre-shipment inspection (PSI). If there is an issue with SN74BCT245N, 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 SN74BCT245N part is unused and in its original packaging.
Return procedure for SN74BCT245N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74BCT245N Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
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…
