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Texas Instruments SN74HCT245DBRG4
- Part No.:
- SN74HCT245DBRG4
- Manufacturer:
- Texas Instruments
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
SN74HCT245DBRG4.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,918
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Product details
Overview
SN74HCT245DBRG4 from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in 5-V logic systems. It features ±6-mA output drive at 5 V, 14-ns typical propagation delay (VCC = 5.5 V), and operates across –40°C to +85°C. It is used in ribbon-cable interconnects between MCUs and remote peripherals where signal integrity and drive strength are critical.
For engineers reviewing the SN74HCT245DBRG4 datasheet, SN74HCT245DBRG4 pinout, SN74HCT245DBRG4 application, or SN74HCT245DBRG4 equivalent, key selection criteria include direction-control logic level compatibility, 3-state isolation timing (ten/tdis ≤ 52 ns), TTL-voltage input thresholds (VIH = 2 V min), and SSOP-20 thermal performance (RθJA = 84.6°C/W).
Technical Context
The SN74HCT245DBRG4 implements a standard '245 logic function with active-low output enable (OE) and unidirectional direction control (DIR). Its CMOS HCT process ensures TTL-compatible inputs while delivering rail-to-rail 3-state outputs capable of driving up to 15 LSTTL loads.
Propagation delay is balanced across A→B and B→A paths (tpd ≤ 25 ns at VCC = 5.5 V, CL = 50 pF), and switching noise is minimized by center-aligned VCC/GND pins. The device supports hot-swap isolation via OE-controlled high-impedance state, with tdis ≤ 45 ns and ten ≤ 52 ns under recommended conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply voltage | 4.5 V to 5.5 V - tolerant of standard 5-V rail variation; no external regulation required. |
| Propagation delay (tpd) | 14 ns typical (5.5 V, CL = 50 pF) - enables reliable 35-MHz bus operation with margin. |
| Output drive | ±6 mA at 5 V - sufficient to drive 15 LSTTL loads directly without external buffers. |
| Static supply current (ICC) | 80 µA maximum - ultra-low quiescent power for always-on bus isolation stages. |
| Input voltage compatibility | TTL-level (VIH ≥ 2 V, VIL ≤ 0.8 V) - interoperable with legacy 5-V TTL and CMOS logic families. |
| Operating temperature | –40°C to +85°C - qualified for industrial-grade embedded systems and factory automation. |
| ESD rating (HBM) | ±1500 V - meets JEDEC JS-001 for robust handling in manufacturing and field service. |
Pinout & Package
SN74HCT245DBRG4 is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch, 7.80 mm × 7.20 mm body size, and exposed pad-less construction. It is RoHS-compliant, moisture-sensitive level 1 (unlimited reflow), and marked "HT245".
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction control input | High = A→B data flow; Low = B→A; determines signal path polarity during active operation. |
| 2–9 (A1–A8) | Port A I/O terminals | Bidirectional data channels tied to local bus; high-impedance when OE = high or DIR conflicts with bus state. |
| 10 (GND) | Ground reference | Primary return path for all I/O and supply currents; must be low-inductance connection to minimize ground bounce. |
| 11–18 (B8–B1) | Port B I/O terminals | Reverse-ordered B-port pins (B8 to B1); match A-port channel mapping for PCB layout symmetry. |
| 19 (OE) | Active-low output enable | High = all A/B ports enter high-Z state; critical for bus arbitration and multi-drop isolation. |
| 20 (VCC) | Power supply | 5-V nominal supply; requires local 0.1-µF ceramic bypass capacitor placed adjacent to pin. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional bus isolation | Enables full-duplex communication over shared physical media (e.g., ribbon cables) without external direction logic. |
| Low-noise pinout | Center-placed VCC and GND pins reduce simultaneous switching noise and improve signal integrity on dense PCBs. |
| Fast 3-state enable/disable | ten ≤ 52 ns and tdis ≤ 45 ns (5.5 V, CL = 50 pF) - supports dynamic bus sharing in real-time control loops. |
| TTL-compatible inputs | VIH = 2 V min / VIL = 0.8 V max - eliminates need for level shifters when interfacing with legacy 5-V logic. |
| Ultra-low static current | ICC ≤ 80 µA - suitable for battery-backed or energy-constrained systems requiring persistent bus presence. |
Applications
| Factory Automation I/O Expansion | Multi-Function Printer Engine Control |
|---|---|
|
Use Scenario: Extending parallel control signals from a central PLC to distributed I/O modules over 30-cm ribbon cables. IC Role / Device Role / Timing Role: Bidirectional buffer isolating master controller from slave modules; DIR selects command vs. status flow; OE enables hot-swap module insertion. Use Value: Prevents signal degradation and timing skew across long traces, enabling deterministic response within 25-ns timing budget. |
Use Scenario: Interfacing an ASIC-based print engine controller with motor driver boards and sensor arrays inside compact MFP chassis. IC Role / Device Role / Timing Role: Level-shifting and drive-strengthening transceiver on shared data bus; manages bidirectional firmware updates and real-time sensor feedback. Use Value: Delivers ±6-mA drive to overcome capacitive loading from multiple motor drivers, maintaining clean edges at 10-MHz update rates. |
| Electronic Point-of-Sale Terminal Backplane | Telecom Infrastructure Shelf Management |
|
Use Scenario: Connecting touchscreen controller, receipt printer, and cash drawer interfaces to a mainboard via rigid-flex backplane. IC Role / Device Role / Timing Role: Bus repeater providing impedance matching and noise immunity; OE synchronizes peripheral power-up sequencing. Use Value: Eliminates signal reflections and crosstalk in multi-drop configurations, ensuring error-free transaction handshaking. |
Use Scenario: Isolating shelf management MCU from hot-swappable line cards in carrier-grade telecom chassis. IC Role / Device Role / Timing Role: Safe bus gate controlling access to card identification EEPROMs and status registers; DIR manages read/write direction per card slot. Use Value: Enables glitch-free card insertion/removal with <50-ns isolation latency, meeting GR-63-CORE reliability requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT245DWRG4 | SOIC-20 package (12.8 mm × 7.5 mm); RθJA = 70.4°C/W; same electrical specs and marking "HCT245". | Better thermal dissipation in airflow-rich environments; larger footprint suits through-hole prototyping or legacy layouts. | Select when board space allows SOIC and thermal margin >15°C above SSOP is needed. |
| SN74LVC245APWR | 3.3-V only (1.65–3.6 V); lower drive (±24 mA); faster tpd = 5.3 ns; different VIH/VIL thresholds. | Not pin-compatible; requires level translation for 5-V systems; suited for modern low-voltage FPGA/MCU interconnects. | Choose only for new 3.3-V designs where speed >100 MHz and power <10 mW per channel are prioritized. |
Compared with SN74HCT245DWRG4 and SN74LVC245APWR, the SN74HCT245DBRG4 offers optimal balance of 5-V compatibility, SSOP space efficiency, and industrial temperature support-making it the preferred choice for retrofitting legacy 5-V infrastructure with minimal layout change.
Availability
SN74HCT245DBRG4 is available at Aetrix Electronics and suitable for factory automation I/O expansion, electronic point-of-sale terminal backplanes, and telecom shelf management requiring stable component supply across extended production lifecycles.
Supply support for SN74HCT245DBRG4 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 SN74HCT245DBRG4 belongs to TI's industry-standard 74HCT logic family, engineered for robust 5-V system interfacing, bus isolation, and noise-immune data transmission in harsh industrial environments.
FAQ
What is the maximum operating temperature range for SN74HCT245DBRG4?
The SN74HCT245DBRG4 is rated for operation from –40°C to +85°C, qualifying it for industrial-grade applications including factory automation controllers and telecom shelf management units deployed in non-climate-controlled enclosures. This range is verified per JEDEC JESD22-A108 and applies to the SSOP-20 package variant specifically.
Does SN74HCT245DBRG4 support hot-swap bus isolation?
Yes, the SN74HCT245DBRG4 supports hot-swap isolation via its active-low output enable (OE) pin: asserting OE high places all A and B port terminals into high-impedance state within ≤52 ns (ten), preventing bus contention during live insertion or removal of peripheral modules. This behavior is guaranteed across the full –40°C to +85°C range and 4.5–5.5 V supply.
Can SN74HCT245DBRG4 drive 15 LSTTL loads directly?
Yes, the SN74HCT245DBRG4 delivers ±6-mA output drive at 5 V, which meets the 1.6-mA per load requirement for 15 LSTTL inputs (15 × 1.6 mA = 24 mA total sink/source). Its output structure maintains VOL ≤ 0.33 V and VOH ≥ 3.84 V under this load, ensuring valid logic levels without external buffering.
What is the propagation delay of SN74HCT245DBRG4 at 5.5 V?
At VCC = 5.5 V and CL = 50 pF, the SN74HCT245DBRG4 exhibits a typical propagation delay (tpd) of 14 ns and a maximum of 25 ns across A↔B paths. This value is measured per JEDEC JESD66 and confirmed in TI's SCLS020H datasheet revision H, making it suitable for 35-MHz synchronous bus applications with timing margin.
Is SN74HCT245DBRG4 pin-compatible with other '245-family variants?
SN74HCT245DBRG4 shares identical pinout and function mapping with all SN74HCT245 variants in 20-pin packages (SSOP, SOIC, PDIP, TSSOP), including SN74HCT245DWRG4 and SN74HCT245N. Direction (DIR), output enable (OE), A/B port assignments, and power/ground positions are fully consistent-enabling drop-in replacement within the same package footprint.
SN74HCT245DBRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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:
- 6mA, 6mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SSOP
SN74HCT245DBRG4 FAQ
1.How can I place an order for SN74HCT245DBRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HCT245DBRG4 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 SN74HCT245DBRG4 reliable?
The price and inventory of SN74HCT245DBRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HCT245DBRG4 is usually 5 days.
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Once your SN74HCT245DBRG4 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 SN74HCT245DBRG4?
For technical support, including SN74HCT245DBRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HCT245DBRG4 requirements.
6.How does Aetrix verify that SN74HCT245DBRG4 is sourced from the original manufacturer or authorized distributors?
All SN74HCT245DBRG4 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 SN74HCT245DBRG4 meets industry standards.
7.What is the process for return or replacement of SN74HCT245DBRG4?
All SN74HCT245DBRG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74HCT245DBRG4, 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 SN74HCT245DBRG4 part is unused and in its original packaging.
Return procedure for SN74HCT245DBRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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