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onsemi 74ABT245CPC
- Part No.:
- 74ABT245CPC
- Manufacturer:
- onsemi
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
74ABT245CPC.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,381
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Product details
Overview
74ABT245CPC from Fairchild Semiconductor is an octal bi-directional transceiver with 3-STATE outputs in a 20-lead PDIP package, designed for bus isolation and level translation between two 8-bit data buses. It supports 5V operation (4.5–5.5V), delivers 64 mA sink / 32 mA source drive per I/O, and features active-low Output Enable (OE) and Transmit/Receive (T/R) control for direction management. Used in legacy industrial backplanes and microcontroller peripheral expansion interfaces.
For engineers reviewing the 74ABT245CPC datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed 3-STATE timing (tPZH ≤ 6.0 ns), simultaneous switching noise immunity, latchup protection, and hot-insertion capability - critical for reliable bus arbitration in mixed-load systems.
Technical Context
The 74ABT245CPC implements non-inverting bidirectional buffering with independent OE and T/R control logic: OE = HIGH forces both A and B ports into high-impedance, while T/R = HIGH enables A→B data flow and T/R = LOW enables B→A flow. All eight channels operate synchronously under shared control signals.
It meets ABT-series specifications including guaranteed output skew ≤ 2.3 ns (HL transitions), dynamic input thresholds (VIHD ≥ 1.7 V, VILD ≤ 0.9 V at VCC = 5.0 V), and AC performance validated for both 50 pF and 250 pF loads - enabling robust operation across PCB trace capacitance variations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | +4.5 V to +5.5 V - ensures compatibility with standard TTL/CMOS 5V systems and tolerates rail droop during transient loading. |
| Output Sink/Source | 64 mA sink / 32 mA source per pin - drives heavy capacitive loads and multiple TTL inputs without external buffers. |
| Propagation Delay | tPLH/tPHL ≤ 3.6 ns (CL = 50 pF) - enables >100 MHz toggle frequency in point-to-point bus configurations. |
| 3-STATE Enable/Disable | tPZH ≤ 6.0 ns, tPHZ ≤ 6.1 ns - minimizes bus contention window during direction or enable transitions. |
| Input Thresholds | VIH ≥ 2.0 V, VIL ≤ 0.8 V - provides 0.4 V noise margin against TTL-compatible logic levels. |
| I/O Capacitance | CI/O = 11.0 pF - limits signal degradation on stubbed or branched bus topologies. |
| Operating Temperature | −40°C to +85°C - qualified for industrial ambient environments without derating. |
Pinout & Package
74ABT245CPC uses a 20-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide body (Package Number N20A). Pin spacing is 0.100", row spacing is 0.300", and lead finish is tin-lead.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OE) | Output Enable Input | Active-low global control: HIGH disables all A/B I/Os into high-Z; essential for bus sharing and conflict avoidance. |
| 2–9 (A0–A7) | Side A Bidirectional I/O | 8-bit port connected to local bus or controller; functions as input or output depending on T/R state. |
| 10 (GND) | Ground Reference | Primary return path for all internal logic and I/O current; must be low-impedance to suppress ground bounce. |
| 11–18 (B0–B7) | Side B Bidirectional I/O | 8-bit port connected to remote bus or peripheral; direction synchronized with A-side via shared T/R signal. |
| 19 (T/R) | Transmit/Receive Control | Active-HIGH selects A→B flow; active-LOW selects B→A flow - defines real-time data path directionality. |
| 20 (VCC) | Power Supply | +4.5 V to +5.5 V supply; requires local 0.1 µF ceramic decoupling adjacent to pin 20. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional non-inverting buffer | Preserves logic polarity across both A→B and B→A paths - eliminates need for external inversion logic in full-duplex links. |
| 64 mA sink capability per I/O | Drives up to 16 standard TTL loads or long PCB traces (>10 cm) without signal integrity loss. |
| Guaranteed output skew ≤ 2.3 ns | Ensures deterministic parallel data capture across all 8 bits - critical for synchronous bus receivers. |
| Non-destructive hot insertion | Withstands live insertion into powered backplanes without latchup or damage - supports field-replaceable module designs. |
| High-impedance glitch-free power-up | Outputs remain in high-Z during VCC ramp (−40°C to +85°C), preventing spurious bus writes at power-on reset. |
Applications
| Industrial Backplane Interface | Microcontroller Peripheral Expansion |
|---|---|
|
Use Scenario: Isolating CPU address/data bus from modular I/O cards in programmable logic controllers (PLCs). IC Role / Device Role / Timing Role: Bidirectional bus transceiver managing 8-bit data handshaking between main controller and field modules. Use Value: 64 mA drive strength sustains signal integrity across 20 cm backplane traces; 3-STATE timing prevents bus contention during card hot-swap. |
Use Scenario: Extending GPIO count of an 8-bit MCU (e.g., 8051) to interface with parallel LCD, keypad, and ADC peripherals. IC Role / Device Role / Timing Role: Level-translating and direction-controlled data bridge between MCU port and peripheral subsystems. Use Value: Active-low OE allows software-controlled bus release; non-inverting behavior preserves firmware bit-mapping without logic inversion overhead. |
| Legacy Memory Bus Buffering | Test Equipment Signal Routing |
|
Use Scenario: Driving SRAM or EPROM data lines in vintage computer repair and retro-computing hardware. IC Role / Device Role / Timing Role: Bi-directional data path conditioner between CPU and memory chips operating at 5V TTL levels. Use Value: Guaranteed VIH/VIL margins (2.0 V / 0.8 V) ensure reliable read/write cycles across aging memory devices with degraded thresholds. |
Use Scenario: Reconfigurable signal routing matrix in automated test equipment (ATE) for DUT interface adaptation. IC Role / Device Role / Timing Role: Programmable bus switch enabling dynamic connection of stimulus sources to measurement nodes. Use Value: Simultaneous switching noise suppression and latchup protection prevent false triggers during multi-channel pattern generation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bi-directional bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ABT245N | Same ABT logic family, identical pinout and DC/AC specs; manufactured by Texas Instruments with tighter production lot control. | No functional difference; TI version exhibits lower typical ICCZ (35 µA vs 50 µA) but same max ratings. | Select SN74ABT245N when requiring TI's extended product longevity program or dual-sourcing assurance. |
| 74ACT245PC | ACT-family variant: higher speed (tPLH ≤ 2.5 ns), lower drive (24 mA sink), and stricter VCC tolerance (4.5–5.5 V same, but no 7V abs max). | Not suitable for high-current bus loads; preferred where propagation delay dominates over drive strength. | Choose 74ACT245PC only if system load capacitance is ≤ 30 pF and sink current demand is < 30 mA per line. |
Compared with SN74ABT245N and 74ACT245PC, the 74ABT245CPC offers optimal balance of drive strength, noise immunity, and legacy PDIP compatibility - making it the preferred choice for industrial retrofits and through-hole prototyping where 64 mA per pin and hot-insertion robustness are mandatory.
Availability
74ABT245CPC is available at Aetrix Electronics and suitable for industrial backplane interfaces, microcontroller peripheral expansion, and legacy memory bus buffering requiring stable component supply and long-term obsolescence mitigation.
Supply support for 74ABT245CPC 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog and logic ICs, acquired by ON Semiconductor in 2016; its ABT logic family remains widely supported in industrial design libraries.
The 74ABT245CPC belongs to Fairchild's Advanced BiCMOS Transceiver (ABT) product line, engineered for high-noise-margin, high-drive 5V bus interfacing in industrial control and instrumentation systems.
FAQ
What is the maximum capacitive load the 74ABT245CPC can drive while maintaining specified timing?
The 74ABT245CPC is characterized for CL = 50 pF and CL = 250 pF loads. At 250 pF, propagation delay increases to ≤ 8.5 ns (tPLH/tPHL) and 3-STATE disable time extends to ≤ 11.0 ns (tPLZ), but remains within guaranteed limits. For reliable operation beyond 250 pF, external series termination or reduced edge rates are recommended.
Does the 74ABT245CPC support hot insertion into a live 5V bus?
Yes, the 74ABT245CPC features non-destructive hot insertion capability per its datasheet. This is enabled by internal clamp diodes, latchup protection rated to −500 mA, and controlled power-up sequencing that holds outputs in high-Z until VCC stabilizes - verified across −40°C to +85°C.
What happens to the A and B ports when OE is HIGH and T/R is floating?
When OE is HIGH, both A and B ports are forced into high-impedance regardless of T/R state. A floating T/R has no effect because the internal output drivers are disabled. However, T/R must be actively driven (not left floating) during normal operation to prevent undefined direction control and potential shoot-through risk.
Can the 74ABT245CPC be used with 3.3V logic systems?
No - the 74ABT245CPC is a 5V-only device with VCC range 4.5–5.5 V and absolute maximum input voltage of +7.0 V. Its VIH minimum is 2.0 V, but driving it from 3.3V logic risks marginal recognition and violates recommended operating conditions; use a level-shifting transceiver like 74LVC4245 instead.
How does the 74ABT245CPC handle simultaneous switching of all eight outputs?
The 74ABT245CPC guarantees simultaneous switching performance: output skew ≤ 2.3 ns (HL), dynamic VOL/VOLP limits (0.7–1.0 V), and noise immunity specs validated with all eight outputs switching. This ensures clean parallel data capture in synchronous bus architectures without added timing guardbands.
74ABT245CPC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74ABT
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- 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:
- 32mA, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
74ABT245CPC FAQ
1.How can I place an order for 74ABT245CPC through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ABT245CPC 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 74ABT245CPC reliable?
The price and inventory of 74ABT245CPC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ABT245CPC is usually 5 days.
3.What payment methods are accepted for 74ABT245CPC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ABT245CPC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ABT245CPC?
74ABT245CPC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ABT245CPC 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 74ABT245CPC?
For technical support, including 74ABT245CPC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ABT245CPC requirements.
6.How does Aetrix verify that 74ABT245CPC is sourced from the original manufacturer or authorized distributors?
All 74ABT245CPC 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 74ABT245CPC meets industry standards.
7.What is the process for return or replacement of 74ABT245CPC?
All 74ABT245CPC units undergo pre-shipment inspection (PSI). If there is an issue with 74ABT245CPC, 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 74ABT245CPC part is unused and in its original packaging.
Return procedure for 74ABT245CPC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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