My Inquiry
My Account
Texas Instruments SN74AHCT245DW
- Part No.:
- SN74AHCT245DW
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74AHCT245DW.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,911
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74AHCT245DW from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data bus communication between A and B ports. It operates from 4.5 V to 5.5 V, supports TTL-voltage-compatible inputs (VIH = 2 V, VIL = 0.8 V), delivers ±8 mA output drive, and features direction (DIR) and output-enable (OE) control for isolated bus management in industrial control backplanes.
For engineers reviewing the SN74AHCT245DW datasheet, SN74AHCT245DW pinout, SN74AHCT245DW application, or SN74AHCT245DW equivalent, this page provides verified functional modes, SOIC-20 package dimensions, switching timing (tPLH/tPHL ≤ 10 ns at 5 V, CL = 15 pF), thermal resistance (RθJA = 96.2 °C/W), and confirmed alternatives for 5 V bus interface designs.
Technical Context
The SN74AHCT245DW implements dual-rail CMOS logic with TTL-compatible input thresholds and 3-state output control. Its DIR pin selects data flow direction (A→B or B→A), while OE enables or disables all eight transceivers simultaneously into high-impedance state.
It uses balanced output drive to minimize ringing, supports overvoltage-tolerant inputs up to 5.5 V, and exhibits latch-up immunity exceeding 250 mA per JESD 17. The device is optimized for 5 V operation but accepts 3.3 V logic inputs, enabling level translation in mixed-voltage systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5 V logic rails and tolerance to supply ripple. |
| Input Thresholds | VIH = 2 V, VIL = 0.8 V - guarantees reliable recognition of TTL-level signals from legacy or microcontroller sources. |
| Output Drive | ±8 mA at VOH/VOL - sufficient for driving multiple CMOS loads without external buffering in point-to-point or lightly loaded buses. |
| Propagation Delay | tPLH/tPHL ≤ 10 ns (CL = 15 pF, VCC = 5 V) - enables use in 50 MHz–100 MHz data transfer applications with margin. |
| Thermal Resistance | RθJA = 96.2 °C/W (SOIC-20) - defines maximum power dissipation limit (~150 mW at ΔT = 14.4 °C rise) under natural convection. |
| ESD Rating | HBM ±2000 V - meets industrial-grade ESD robustness requirements without additional protection circuitry. |
| Operating Temperature | –40 °C to +125 °C - qualified for extended industrial environments including motor drives and PLC I/O modules. |
Pinout & Package
SN74AHCT245DW is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with nominal body size 12.80 mm × 7.50 mm and standard 0.050″ (1.27 mm) lead pitch. The package is RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction control input | Logic level determines data flow direction: LOW = B→A, HIGH = A→B; must be stable during data transfer. |
| 2–9 (A1–A8) | Port A bidirectional I/O | Connects to source bus; functions as input or output depending on DIR and OE states. |
| 10 (GND) | Ground reference | Primary return path for all internal logic and I/O current; requires low-impedance PCB connection. |
| 11–18 (B1–B8) | Port B bidirectional I/O | Connects to destination bus; complements A-port behavior under DIR control. |
| 19 (OE) | Output enable input | Active-LOW control: LOW enables transceivers, HIGH places all A/B pins in high-impedance state for bus isolation. |
| 20 (VCC) | Positive supply | 5 V nominal power rail; requires local 0.1 µF bypass capacitor placed adjacent to pin for noise suppression. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-voltage compatible inputs | Accepts 0.8 V/2 V thresholds - eliminates need for level shifters when interfacing with legacy 5 V TTL or 3.3 V MCU GPIOs. |
| Asynchronous bidirectional control | Independent DIR and OE pins - enables flexible bus arbitration without clock synchronization or protocol overhead. |
| High-impedance isolation | OE-driven 3-state outputs - electrically disconnects A and B buses during reset, standby, or fault conditions. |
| Slow edge rate design | Controlled slew minimizes overshoot/undershoot - reduces EMI and eliminates termination resistors in short-run PCB traces. |
| Latch-up immunity | >250 mA per JESD 17 - ensures robustness against transient current faults in noisy industrial environments. |
Applications
| Industrial Backplane Interface | Microcontroller Bus Expansion |
|---|---|
|
Use Scenario: Isolating and translating data between a 5 V PLC main controller and distributed 3.3 V sensor nodes across a 20 cm backplane. IC Role / Device Role / Timing Role: Bidirectional level translator and bus driver managing A-port (controller side) and B-port (sensor side) under DIR-controlled flow and OE-based hot-swap isolation. Use Value: Eliminates need for separate level shifters and buffers; ±8 mA drive sustains signal integrity across unterminated stubs up to 15 cm. |
Use Scenario: Expanding GPIO count of an ARM Cortex-M4 MCU by connecting parallel peripherals (ADC, DAC, display driver) to a shared 8-bit data bus. IC Role / Device Role / Timing Role: Synchronized bus transceiver enabling time-multiplexed access to peripherals via DIR-selectable direction and OE-gated enable. Use Value: Enables single-cycle read/write handshaking at up to 50 MHz; slow edges prevent ringing on 4-layer FR4 traces with 50 Ω characteristic impedance. |
| Legacy System Upgrade Bridge | Test Equipment Signal Routing |
|
Use Scenario: Integrating modern FPGA-based modules into aging 5 V ISA-bus test equipment while preserving backward compatibility with TTL peripherals. IC Role / Device Role / Timing Role: Protocol-transparent bus coupler that isolates legacy address/data lines during FPGA reconfiguration using OE assertion. Use Value: Prevents bus contention during power-up sequencing; VIH = 2 V ensures reliable detection of marginal TTL outputs degraded over decades. |
Use Scenario: Dynamically routing digital stimulus signals between multiple DUT interfaces in automated test equipment with shared resource constraints. IC Role / Device Role / Timing Role: Reconfigurable signal path selector where DIR sets source/sink orientation and OE gates signal injection during calibration cycles. Use Value: Enables sub-10 ns signal path switching without glitch generation; high-impedance state prevents loading of unused channels during multiplexing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AHCT245DWR | Same SOIC-20 package, identical electrical specs, tape-and-reel packaging (2000 pcs/reel); active production status vs. DW's obsolete status. | Designed for automated SMT assembly; same footprint and thermal profile as SN74AHCT245DW. | Select DWR for new designs requiring volume procurement and long-term supply continuity. |
| SN74LVC245A | Lower voltage operation (1.65–3.6 V), higher drive (±24 mA), faster propagation (tPD ≈ 5.3 ns), but not TTL-input compatible (VIH = 2 V only at VCC = 3.3 V). | Suitable for 3.3 V-only systems; cannot directly replace SN74AHCT245DW in 5 V or mixed-voltage environments without redesign. | Choose LVC245A only when migrating fully to 3.3 V logic and requiring higher speed or drive strength. |
Compared with SN74AHCT245DW, SN74AHCT245DWR offers identical functionality with assured supply chain support, while SN74LVC245A trades TTL compatibility for lower-voltage operation and improved performance-making it unsuitable as a drop-in replacement in 5 V systems.
Availability
SN74AHCT245DW is available at Aetrix Electronics and suitable for industrial backplane interfaces, microcontroller bus expansion, legacy system upgrade bridges, and test equipment signal routing requiring stable component supply and proven interoperability with 5 V TTL logic families.
Supply support for SN74AHCT245DW 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 90 years of innovation in industrial, automotive, and communications markets.
The SN74AHCT245DW belongs to TI's 74AHCT logic family, engineered for robust 5 V bus interfacing with TTL compatibility, high noise immunity, and seamless integration into legacy and mixed-voltage digital systems.
FAQ
What is the operating voltage range for SN74AHCT245DW?
The SN74AHCT245DW operates from 4.5 V to 5.5 V. This range ensures compatibility with standard 5 V power supplies while accommodating typical line regulation and ripple. Operation outside this range may cause functional failure or damage, as specified in the Absolute Maximum Ratings table (VCC min = –0.5 V, max = 7 V).
Does SN74AHCT245DW support 3.3 V logic inputs?
Yes, SN74AHCT245DW accepts 3.3 V logic inputs reliably because its VIH threshold is 2 V and VIL is 0.8 V - both satisfied by 3.3 V CMOS logic levels. This enables direct connection to 3.3 V microcontrollers without level-shifting circuitry, provided VCC remains at 5 V.
What is the function of the DIR and OE pins on SN74AHCT245DW?
DIR controls data direction: HIGH enables A→B transfer, LOW enables B→A transfer. OE is active-LOW output enable: LOW activates transceivers, HIGH places all A/B pins in high-impedance state. Both pins must be driven to valid logic levels; floating inputs may cause undefined behavior or increased ICC.
Can SN74AHCT245DW be used in place of SN74LS245?
SN74AHCT245DW can replace SN74LS245 in most 5 V systems due to matching pinout, 3-state capability, and TTL-compatible inputs. However, SN74AHCT245DW draws significantly less quiescent current (ICC ≤ 40 µA vs. LS245's ~30 mA) and has faster switching, requiring attention to layout-induced ringing not present in slower LS logic.
Is SN74AHCT245DW still in active production?
No - SN74AHCT245DW is marked "Obsolete" in TI's official packaging addendum. The recommended active alternative is SN74AHCT245DWR (same SOIC-20 package, tape-and-reel, full production status), which shares identical electrical and thermal specifications and is supported for long-term industrial supply.
SN74AHCT245DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- 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:
- 8mA, 8mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
SN74AHCT245DW FAQ
1.How can I place an order for SN74AHCT245DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHCT245DW 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 SN74AHCT245DW reliable?
The price and inventory of SN74AHCT245DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHCT245DW is usually 5 days.
3.What payment methods are accepted for SN74AHCT245DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHCT245DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHCT245DW?
SN74AHCT245DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHCT245DW 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 SN74AHCT245DW?
For technical support, including SN74AHCT245DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHCT245DW requirements.
6.How does Aetrix verify that SN74AHCT245DW is sourced from the original manufacturer or authorized distributors?
All SN74AHCT245DW 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 SN74AHCT245DW meets industry standards.
7.What is the process for return or replacement of SN74AHCT245DW?
All SN74AHCT245DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHCT245DW, 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 SN74AHCT245DW part is unused and in its original packaging.
Return procedure for SN74AHCT245DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74AHCT245DW 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…
