My Inquiry
My Account
Texas Instruments SN74F245DW
- Part No.:
- SN74F245DW
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74F245DW.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,716
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74F245DW from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 8-bit buses. It features direction control (DIR), output enable (OE), and supports 0°C to 70°C operation with 5 V supply. Its 20-pin SOIC (DW) package enables compact board layout in legacy industrial and computing systems.
For engineers reviewing the SN74F245DW datasheet, SN74F245DW pinout, SN74F245DW application, or SN74F245DW equivalent, this page delivers verified electrical specs, functional role in bus isolation and level translation, real-world use cases in backplane interfaces and memory expansion, and validated alternative options for obsolescence mitigation.
Technical Context
The SN74F245DW implements TTL-compatible 3-state logic with dual 8-bit bidirectional I/O ports (A1–A8 and B1–B8), controlled by a single DIR input to select data flow direction (A→B or B→A) and an OE input to place all outputs in high-impedance state. It operates strictly at 5 V (4.5–5.5 V range) and is not compatible with mixed-voltage or CMOS-level signaling without external level-shifting.
Its propagation delay ranges from 1.7 ns to 7 ns (tPLH/tPHL) under 50 pF load, with output drive capability of 24 mA (A-side) and 64 mA (B-side) at low state, confirming its suitability for driving moderate-capacitance PCB traces and legacy TTL loads - not high-speed or low-power applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - requires stable 5 V rail; no internal regulation or wide-VCC tolerance. |
| Operating Temperature | 0°C to 70°C - commercial-grade rating; unsuitable for extended industrial or automotive ambient. |
| Output Drive (IOL) | A1–A8: 24 mA; B1–B8: 64 mA - B-side drives heavier loads, critical for bus termination and fanout planning. |
| Propagation Delay | 1.7–7 ns (A↔B) - defines maximum achievable bus clock rate in non-synchronous systems. |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V - TTL-compatible logic levels; incompatible with 3.3 V or CMOS thresholds without interface circuitry. |
| 3-State Enable Time | tPZL = 1.2–7.5 ns, tPHZ = 1.7–7.5 ns - fast bus isolation essential for glitch-free bus sharing in multi-master designs. |
Pinout & Package
SN74F245DW uses a 20-pin SOIC (DW) package, 7.5 mm × 12.8 mm body size, 1.27 mm lead pitch, 2.65 mm max height, and gull-wing leads - compatible with standard SOIC reflow profiles (MSL Level-1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction Control Input | Low = B→A data flow; High = A→B data flow; determines signal path polarity across transceiver. |
| 2–9 (A1–A8) | Port A I/O | 8-bit bidirectional data port; connects to local bus or microcontroller data lines. |
| 10 (GND) | Ground Reference | Primary return path for all I/O and supply currents; must be low-impedance connection. |
| 11–18 (B1–B8) | Port B I/O | 8-bit bidirectional data port; connects to peripheral bus, memory, or expansion interface. |
| 19 (OE) | Output Enable Input | Active-low; disables all outputs into high-impedance state to isolate both buses simultaneously. |
| 20 (VCC) | Power Supply | +5 V supply only; no reverse-voltage or overvoltage protection; decoupling capacitor required. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional Data Flow | Single DIR pin selects A→B or B→A path - eliminates need for separate transmit/receive buffers in shared-bus architectures. |
| True 3-State Outputs | All 16 I/Os enter high-Z when OE = High - enables clean bus arbitration and prevents contention during idle or fault conditions. |
| TTL-Compatible Interface | VIL = 0.8 V / VIH = 2.0 V matches legacy 5 V TTL logic families - ensures interoperability with 74LS, 74AS, and early microcontrollers. |
| Asymmetric Output Drive | B-side delivers 64 mA vs. A-side's 24 mA - optimized for driving longer traces or higher-fanout loads on the peripheral bus side. |
| Fast Bus Isolation | tPZL as low as 1.2 ns - minimizes bus float time during mode switching, reducing risk of metastability or data corruption. |
Applications
| Industrial Backplane Interface | Legacy Microcontroller Expansion |
|---|---|
|
Use Scenario: Interfacing an 8-bit microcontroller (e.g., 8051) to a parallel I/O expansion card via a 20 cm backplane trace. IC Role / Device Role / Timing Role: Bidirectional bus transceiver enabling read/write access to peripheral registers while isolating controller from noise on the expansion bus. Use Value: 64 mA B-side drive sustains signal integrity across long traces; 3-state control prevents bus contention during interrupt-driven transfers. |
Use Scenario: Adding external RAM or EPROM to an older embedded system using a 5 V address/data multiplexed bus. IC Role / Device Role / Timing Role: Data bus buffer that separates CPU data lines from memory device I/O, synchronized with MEMR/MEMW strobes. Use Value: Sub-7 ns propagation delay meets timing budgets for 12 MHz 8085/8088-based systems; OE-controlled isolation avoids memory access conflicts. |
| Printer Parallel Port Controller | Test Equipment Data Capture |
|
Use Scenario: Buffering bidirectional Centronics-style parallel port signals between host MCU and printer interface ASIC. IC Role / Device Role / Timing Role: Direction-controlled transceiver managing handshake (BUSY, ACK) and data (D0–D7) lines in both directions. Use Value: DIR pin simplifies firmware control of data flow direction; TTL thresholds match standard printer port voltage levels. |
Use Scenario: Capturing 8-bit digital waveform data from DUT into test instrument memory using a triggered acquisition cycle. IC Role / Device Role / Timing Role: Isolating acquisition logic from main processor bus during high-speed sampling bursts. Use Value: Fast tPZL (1.2 ns min) ensures immediate bus release after capture completion, preventing data overwrite or bus lockup. |
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-side), slower speed (12–25 ns), same 5 V / 0°C–70°C spec. | Acceptable where timing margin exists and power consumption is prioritized over speed. | Drop-in replacement for cost-sensitive, lower-speed legacy upgrades; verify setup/hold timing in high-frequency designs. |
| SN74HC245N | CMOS process, 2–6 V supply, 3.3 V logic compatible, 7–25 ns delay, 35 mA drive. | Enables mixed-voltage systems but requires level-aware design; not TTL-input compatible. | Preferred for new designs targeting 3.3 V domains or lower power; not suitable as direct SN74F245DW substitute without voltage translation. |
Compared with SN74F245DW, SN74LS245N trades speed for robustness in noisy environments, while SN74HC245N shifts to CMOS logic family benefits - neither offers pin-to-pin compatibility without board-level adjustments, and both require validation of timing margins and voltage domain alignment.
Availability
SN74F245DW is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy microcontroller expansions, and parallel port controllers requiring stable component supply amid ongoing obsolescence management.
Supply support for SN74F245DW 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions with broad industrial and automotive reach.
The SN74F245DW belongs to TI's 74F (Fast TTL) logic family, engineered for high-speed 5 V digital systems where propagation delay and drive strength outweigh power efficiency - targeting mid-1980s to early-1990s computing and instrumentation platforms.
FAQ
Is SN74F245DW still in active production?
No - according to TI's official packaging addendum, SN74F245DW is marked "Obsolete". However, Aetrix Electronics maintains verified legacy stock with full traceability and provides engineering support for continued use in maintenance and repair programs. The active tape-and-reel variant is SN74F245DWR.
What is the maximum capacitive load SN74F245DW can drive reliably?
SN74F245DW is characterized for CL = 50 pF in switching specifications. Driving >75 pF may increase propagation delay beyond 7 ns and degrade edge rates; for >100 pF loads, consider adding series termination or verifying signal integrity with oscilloscope measurements on the target board.
Can SN74F245DW interface directly with 3.3 V logic devices?
No - SN74F245DW has TTL input thresholds (VIH = 2.0 V, VIL = 0.8 V) and 5 V output swing. While 3.3 V outputs may register as valid inputs, SN74F245DW outputs exceed 3.3 V absolute maximum ratings of most 3.3 V ICs. External level-shifting circuitry is required for safe interfacing.
Does SN74F245DW support hot insertion or live bus swapping?
No - SN74F245DW lacks bus-hold, power-up 3-state, or Ioff protection. Applying voltage to I/O pins while VCC is unpowered risks latch-up or damage. Hot-swap operation requires external protection circuitry or a modern transceiver with Ioff and power-off protection.
What is the recommended decoupling for SN74F245DW?
TI recommends a minimum 0.1 µF ceramic capacitor placed within 5 mm of the VCC (pin 20) and GND (pin 10) pins. For boards with multiple SN74F245DW units or high switching activity, add a bulk 4.7–10 µF tantalum or aluminum electrolytic capacitor per 5–10 devices near the power entry point.
SN74F245DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74F
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
SN74F245DW FAQ
1.How can I place an order for SN74F245DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74F245DW 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 SN74F245DW reliable?
The price and inventory of SN74F245DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74F245DW is usually 5 days.
3.What payment methods are accepted for SN74F245DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74F245DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74F245DW?
SN74F245DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74F245DW 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 SN74F245DW?
For technical support, including SN74F245DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74F245DW requirements.
6.How does Aetrix verify that SN74F245DW is sourced from the original manufacturer or authorized distributors?
All SN74F245DW 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 SN74F245DW meets industry standards.
7.What is the process for return or replacement of SN74F245DW?
All SN74F245DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74F245DW, 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 SN74F245DW part is unused and in its original packaging.
Return procedure for SN74F245DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74F245DW 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…
