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Texas Instruments SN74HC245APW
- Part No.:
- SN74HC245APW
- Manufacturer:
- Texas Instruments
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74HC245APW.pdf
- Description:
- IC TXRX NON-INVERT 6V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,080
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Product details
Overview
SN74HC245APW from Texas Instruments is an 8-bit non-inverting bidirectional bus transceiver with 3-state outputs, DIR and OE control inputs, CMOS-level compatibility, and operation across −40 °C to +125 °C. It enables data flow arbitration between two 8-bit buses in microcontroller peripheral expansion, memory-mapped I/O, and legacy parallel interface bridging.
For engineers reviewing the SN74HC245APW datasheet, SN74HC245APW pinout, SN74HC245APW application, or SN74HC245APW equivalent, key selection criteria include its 3-state output drive capability (±35 mA), propagation delay (7–27 ns at VCC = 4.5–6.0 V), TSSOP-20 package footprint, and CMOS input threshold compatibility with 2.0–6.0 V supply rails.
Technical Context
The SN74HC245APW implements a dual-bus directional buffer using complementary MOS logic, where DIR selects data path direction (A→B or B→A) and active-low OE places all outputs in high-impedance state. Its input clamp diodes permit safe interfacing to voltages exceeding VCC when used with current-limiting resistors.
It operates under JEDEC JESD7A compliance with ESD robustness (HBM >2000 V, MM >200 V) and supports static and dynamic performance across industrial and extended temperature ranges. Input leakage remains ≤±1.0 μA and OFF-state output current ≤±10 μA at full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | High-speed CMOS (74HC), TTL-compatible input thresholds not applicable |
| Bus Width | 8-bit bidirectional data path with independent A- and B-side I/O terminals |
| Supply Voltage Range | 2.0 V to 6.0 V - supports mixed-voltage system interfacing and low-power operation |
| Output Drive | ±35 mA per output - sufficient for driving 50-pF loads and multiple TTL inputs |
| Propagation Delay | 7 ns typical (VCC = 6.0 V, CL = 15 pF) - enables reliable timing in 20+ MHz bus systems |
| Power Dissipation Cap | 500 mW maximum (TSSOP20) - requires thermal derating above 60 °C (5.5 mW/K) |
| Operating Temperature | −40 °C to +125 °C - qualified for industrial and extended-environment applications |
Pinout & Package
TSSOP-20 plastic thin shrink small outline package (SOT360-1), 4.4 mm body width, 0.65 mm lead pitch, 20-terminal surface-mount configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction control input | LOW enables A→B data flow; HIGH enables B→A - determines bus arbitration polarity |
| 2–9 (A0–A7) | Port A I/O | 8-bit bidirectional data terminal on side A - connects to microcontroller or peripheral bus |
| 10 (GND) | Ground reference | 0 V return path for all internal logic and I/O - must be low-impedance for noise immunity |
| 11–18 (B0–B7) | Port B I/O | 8-bit bidirectional data terminal on side B - interfaces to memory, display controller, or external device |
| 19 (OE) | Output enable (active LOW) | Drives all A/B outputs to high-impedance when HIGH - enables bus sharing without contention |
| 20 (VCC) | Positive supply | Primary power rail (2.0–6.0 V); decoupling capacitor required within 10 mm of pin |
Key Features
| Feature | Design Value |
|---|---|
| Non-inverting 3-state outputs | Preserves signal polarity during bidirectional transfer and eliminates bus contention via high-Z isolation |
| Input clamp diodes | Enables safe overvoltage tolerance on A/B pins up to VCC + 0.5 V when used with series current-limiting resistors |
| JEDEC JESD7A compliance | Guarantees interoperability with standard 74-series logic families and PCB layout practices |
| Low input capacitance | CI = 3.5 pF and CI/O = 10 pF - minimizes loading on driving sources and preserves signal edge integrity |
| ESD protection | HBM >2000 V and MM >200 V - meets industrial handling requirements without additional protection circuitry |
Applications
| Microcontroller Peripheral Expansion | Parallel Memory Interface |
|---|---|
Use Scenario: Expanding GPIO count of an ARM Cortex-M4 MCU to drive 8-bit LCD controller and keypad matrix simultaneously. IC Role / Device Role / Timing Role: Bidirectional data buffer arbitrating between MCU data bus and peripheral address/data lines under software-controlled DIR/OE. Use Value: Enables single MCU to manage multiple parallel peripherals without hardware bus contention or timing-critical glue logic. | Use Scenario: Interfacing an FPGA's 8-bit data bus to external SRAM and EPROM in a legacy industrial controller. IC Role / Device Role / Timing Role: Level-shifting and direction-controlled bus repeater synchronizing read/write cycles between FPGA and memory devices. Use Value: Eliminates need for discrete transceivers and reduces PCB layer count by consolidating bus control into one TSSOP-20 IC. |
| Legacy Parallel Port Bridging | Industrial I/O Module Data Hub |
Use Scenario: Adapting a modern SoC's GPIO bank to emulate a PC-style parallel printer port (IEEE 1284) for field equipment communication. IC Role / Device Role / Timing Role: Bidirectional data transceiver translating SoC logic levels to standardized parallel port signaling with configurable direction and tristate control. Use Value: Achieves backward compatibility with installed base of industrial printers and scanners using only one IC and minimal firmware overhead. | Use Scenario: Central data aggregation node in a modular PLC backplane, routing sensor data between analog/digital I/O modules and main CPU. IC Role / Device Role / Timing Role: Isolated bus transceiver managing time-multiplexed access to shared 8-bit data lanes across multiple hot-swappable modules. Use Value: Provides deterministic bus arbitration and fault containment - failure in one module does not disrupt data flow on other lanes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT245PW | TTL-compatible inputs (VIH = 2.0 V min), identical pinout and timing | Better suited for mixed 5 V TTL/CMOS systems; higher ICC at VCC = 5.5 V | Select when interfacing legacy 5 V TTL logic; avoid if system uses <4.5 V supplies |
| 74LCX245MTCX | Lower voltage operation (2.0–3.6 V), higher speed (tpd = 5.5 ns typ), different pinout | Optimized for 3.3 V LVTTL/LVCMOS domains; not drop-in compatible | Choose for 3.3 V-only designs requiring sub-6 ns latency and lower power; requires PCB redesign |
Compared with SN74HC245APW, SN74HCT245PW offers guaranteed TTL input compatibility but higher quiescent current, while 74LCX245MTCX delivers faster switching at lower voltage but demands layout revision due to non-identical pin mapping.
Availability
SN74HC245APW is available at Aetrix Electronics and suitable for microcontroller peripheral expansion, parallel memory interface, and legacy parallel port bridging requiring stable component supply across industrial temperature ranges and long production lifecycles.
Supply support for SN74HC245APW 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer applications.
The SN74HC245APW belongs to TI's 74HC logic family, designed specifically for robust, low-power bidirectional bus interfacing in space-constrained industrial and embedded systems.
FAQ
What is the maximum clock frequency supported by SN74HC245APW in a data bus application?
The SN74HC245APW is not a clocked device and has no internal clock; its usable data rate depends on propagation delay and load. With 7 ns typical tpd (VCC = 6.0 V, CL = 15 pF), it supports reliable 8-bit parallel transfers up to ~20 MHz in well-terminated systems. System-level timing must account for board trace delays and setup/hold margins beyond SN74HC245APW's intrinsic delay.
Does SN74HC245APW support level translation between different supply voltages on Port A and Port B?
No - SN74HC245APW has a single VCC pin (Pin 20) powering both sides; Port A and Port B share the same supply rail. It does not provide voltage-level translation. For mixed-voltage interfacing, external level-shifting circuitry or a dedicated translator IC such as TXB0108 must be used alongside SN74HC245APW.
Can SN74HC245APW be used with a 3.3 V microcontroller and 5 V peripheral without damage?
Yes, provided VCC = 5.0 V and input clamping diodes are used with current-limiting resistors on A/B pins driven by the 3.3 V MCU. The SN74HC245APW's input clamp diodes allow safe operation when VI exceeds VCC by ≤0.5 V, but sustained overvoltage beyond that risks latch-up or damage. Always verify VIH/VIL thresholds at 5.0 V supply before integration.
What is the recommended PCB layout practice for minimizing noise on SN74HC245APW's VCC and GND pins?
Place a 100 nF ceramic decoupling capacitor between VCC (Pin 20) and GND (Pin 10) with trace length <10 mm. Use solid ground plane beneath the TSSOP-20 footprint, avoid splits under the IC, and route high-speed signals (A/B lines) away from noisy power traces. Ensure GND pin has lowest-inductance connection to system ground to suppress switching noise coupling into SN74HC245APW's internal logic.
Is SN74HC245APW pin-compatible with SN74HCT245PW, and can they be interchanged on the same PCB?
Yes - SN74HC245APW and SN74HCT245PW share identical TSSOP-20 (SOT360-1) packaging, pinout, and mechanical dimensions. They are functionally interchangeable in hardware layout; however, SN74HCT245PW uses TTL-compatible input thresholds and draws higher supply current, so firmware and timing analysis must be revalidated after substitution.
SN74HC245APW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- 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:
- 7.8mA, 7.8mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
SN74HC245APW FAQ
1.How can I place an order for SN74HC245APW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HC245APW 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 SN74HC245APW reliable?
The price and inventory of SN74HC245APW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HC245APW is usually 5 days.
3.What payment methods are accepted for SN74HC245APW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HC245APW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HC245APW?
SN74HC245APW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HC245APW 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 SN74HC245APW?
For technical support, including SN74HC245APW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HC245APW requirements.
6.How does Aetrix verify that SN74HC245APW is sourced from the original manufacturer or authorized distributors?
All SN74HC245APW 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 SN74HC245APW meets industry standards.
7.What is the process for return or replacement of SN74HC245APW?
All SN74HC245APW units undergo pre-shipment inspection (PSI). If there is an issue with SN74HC245APW, 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 SN74HC245APW part is unused and in its original packaging.
Return procedure for SN74HC245APW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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