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Texas Instruments SN74BCT640DWRG4
- Part No.:
- SN74BCT640DWRG4
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74BCT640DWRG4.pdf
- Description:
- IC TXRX INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,597
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Product details
Overview
SN74BCT640DWRG4 from Texas Instruments is an 8-bit non-inverting bus transceiver with direction control (DIR) and output-enable (OE), designed for asynchronous bidirectional data transfer between A and B buses in TTL-level systems. It operates at 4.5 V to 5.5 V, supports ±64 mA B-port sink current, features undershoot-protection circuitry, and is rated for 0°C to 70°C industrial temperature range.
For engineers reviewing the SN74BCT640DWRG4 datasheet, SN74BCT640DWRG4 pinout, SN74BCT640DWRG4 application, or SN74BCT640DWRG4 equivalent, key selection criteria include its BiCMOS architecture for low standby current, 3.4 V minimum VOH at −3 mA on A port, 2.0 V minimum VOH at −15 mA on B port, and 3.4 ns typical tPHL propagation delay under 50 pF load.
Technical Context
This device implements a dual-bus bidirectional interface using separate DIR and OE controls: DIR selects data flow direction (A→B or B→A), while OE places outputs in high-impedance state for bus isolation. Its BiCMOS design combines bipolar output drivers for high drive strength with CMOS input stages for reduced DC loading.
Electrical behavior is defined across two I/O ports: A port supports up to 24 mA sink current with 0.35 V max VOL, B port supports up to 64 mA sink current with 0.42 V max VOL at VCC = 4.5 V. Undershoot-protection circuitry on all outputs prevents negative voltage excursions below −0.5 V during fast transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - Ensures compatibility with standard 5 V TTL and mixed-voltage system rails. |
| IOH (A port) | −3 mA min VOH = 2.4 V - Sustains valid TTL high level driving multiple loads. |
| IOL (B port) | 64 mA max VOL = 0.42 V - Delivers robust low-state drive for heavy bus capacitance. |
| tPHL / tPLH | 3.4 ns / 5.6 ns max - Enables reliable operation in sub-10 ns timing-critical bus arbitration. |
| ICCZ (Standby) | 4 mA max - Low quiescent current reduces system power budget in idle states. |
| ESD Rating | >2000 V HBM - Provides built-in protection against handling-induced electrostatic discharge. |
| Operating Temp | 0°C to 70°C - Qualified for commercial and industrial ambient environments. |
Pinout & Package
SN74BCT640DWRG4 uses a 20-pin SOIC (DW) package with 7.5 mm body width, 2.65 mm max height, and 1.27 mm lead pitch per JEDEC MS-013. Pin 1 is marked by a beveled corner or notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | DIR | Direction control input: L enables B→A transfer; H enables A→B transfer. |
| 2–9, 18 | A1–A8 | Input/output terminals for A-side bus - driven when enabled and DIR matches direction. |
| 11–18 | B1–B8 | Input/output terminals for B-side bus - driven when enabled and DIR matches direction. |
| 10 | GND | Ground reference for all internal logic and output drivers. |
| 20 | VCC | Positive supply rail (4.5–5.5 V) powering BiCMOS output stage and input buffers. |
| 19 | OE | Output-enable active-low: L enables transceiver; H forces all A/B pins to high-Z. |
Key Features
| Feature | Design Value |
|---|---|
| BiCMOS Output Architecture | Combines bipolar pull-down strength (64 mA B-port sink) with CMOS input impedance to minimize DC loading on control lines. |
| Undershoot-Protection Circuitry | Prevents output voltage from dropping below −0.5 V during fast edge transitions, eliminating need for external clamping diodes. |
| Power-Up High-Impedance State | Outputs remain in high-Z until VCC stabilizes and control inputs settle, preventing bus contention during power sequencing. |
| Buffered Control Inputs | DIR and OE inputs use buffered stages to reduce input current to ≤0.1 µA at VI = 2.7 V, easing microcontroller GPIO drive requirements. |
| State-of-the-Art ESD Protection | Exceeds 2000 V per MIL-STD-883C Method 3015, enabling safe handling without additional board-level protection. |
Applications
| Industrial PLC Backplane Interface | Legacy ISA Bus Extension |
|---|---|
Use Scenario: Connecting isolated I/O modules to a central controller via shared parallel backplane wiring. IC Role / Device Role / Timing Role: Bidirectional bus transceiver isolating CPU address/data bus from peripheral module bus during configuration or fault recovery. Use Value: Enables hot-swap capability and fault containment using OE-controlled high-Z isolation, with 64 mA B-port drive supporting long trace lengths and multiple drop points. | Use Scenario: Extending original IBM PC/AT ISA bus signals to add-on cards requiring level translation or signal buffering. IC Role / Device Role / Timing Role: Level-shifting and direction-controlled data path between legacy 5 V ISA slots and newer peripheral ASICs. Use Value: Maintains TTL-compatible VOH/VOL margins across full temperature range while providing 3.4 ns tPHL for cycle-accurate timing in 8 MHz ISA environments. |
| Automotive Diagnostic Interface Adapter | Test Equipment Signal Routing Matrix |
Use Scenario: Interfacing J1850 or proprietary diagnostic controllers to vehicle ECU test ports with bidirectional data exchange. IC Role / Device Role / Timing Role: Direction-switched bus bridge translating between master command bus and slave response bus under microcontroller DIR control. Use Value: Undershoot protection eliminates signal integrity issues on noisy automotive harnesses; 0.42 V VOL ensures noise margin >0.8 V at 5 V supply. | Use Scenario: Configurable signal routing in automated test equipment where DUT signals must be dynamically connected to measurement instruments. IC Role / Device Role / Timing Role: Reconfigurable 8-bit bidirectional path controlled by FPGA logic to route analog/digital signals between test channels. Use Value: OE-driven high-Z state allows seamless reconfiguration without bus contention; 20-pin SOIC footprint supports dense PCB layouts in modular instrument chassis. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS640N | Lower drive strength (24 mA B-port sink), higher ICC (48 mA active), no undershoot protection. | Suitable only for low-capacitance, short-distance bus segments with minimal noise. | Select when cost sensitivity outweighs noise immunity and drive requirements. |
| SN74LVC245APW | 3.3 V only (1.65–3.6 V), CMOS I/O, 24 mA drive, no BiCMOS output stage. | Requires level-shifting for 5 V systems; not drop-in compatible with TTL logic families. | Choose for modern low-voltage designs where power efficiency and smaller TSSOP package are prioritized. |
Compared with SN74BCT640DWRG4, SN74LS640N offers lower cost but sacrifices noise immunity and drive capability, while SN74LVC245APW provides lower voltage operation and smaller size but requires system-level voltage translation and lacks the robust 5 V TTL interface.
Availability
SN74BCT640DWRG4 is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy ISA bus extensions, automotive diagnostic adapters, and test equipment signal routing matrices requiring stable component supply across extended production lifecycles.
Supply support for SN74BCT640DWRG4 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 company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
SN74BCT640DWRG4 belongs to TI's 74BCT logic family, engineered for high-drive, noise-immune bidirectional bus interfacing in 5 V TTL systems where reliability under electrical stress and consistent timing performance are critical.
FAQ
What is the maximum operating temperature range for SN74BCT640DWRG4?
The SN74BCT640DWRG4 is characterized for operation from 0°C to 70°C, meeting industrial-grade thermal specifications. This range is confirmed in the recommended operating conditions table of the official SCBS025C datasheet, and applies specifically to the SN74BCT640 variant - distinct from the military-grade SN54BCT640 (−55°C to 125°C). The DW package version (SN74BCT640DWRG4) is not rated beyond 70°C.
Does SN74BCT640DWRG4 support true bidirectional data flow without external logic?
Yes, SN74BCT640DWRG4 supports true bidirectional data flow using only its two control inputs: DIR determines direction (A↔B), and OE enables/disables the transceiver. When OE is low, data passes synchronously in the selected direction; when OE is high, both A and B ports enter high-impedance state. No external gates or latches are required to manage direction or isolation.
What is the purpose of undershoot-protection circuitry in SN74BCT640DWRG4?
The undershoot-protection circuitry in SN74BCT640DWRG4 prevents output voltages from falling below −0.5 V during fast signal transitions, particularly on unterminated or long traces. This eliminates the need for external Schottky clamping diodes in noisy environments such as industrial backplanes or automotive harnesses, directly improving signal integrity and reducing BOM count.
Can SN74BCT640DWRG4 operate reliably at 4.5 V supply voltage?
Yes, SN74BCT640DWRG4 is fully specified down to 4.5 V VCC. Electrical characteristics tables confirm VOH ≥ 2.4 V (A port, IOH = −3 mA) and VOL ≤ 0.42 V (B port, IOL = 64 mA) at VCC = 4.5 V. Propagation delays remain within spec (tPHL ≤ 3.8 ns), ensuring functional correctness in brown-out or marginally regulated 5 V systems.
Is SN74BCT640DWRG4 RoHS compliant and lead-free?
Yes, SN74BCT640DWRG4 is RoHS compliant with lead-free terminal finish (NIPDAU). Per TI's Package Option Addendum, the DW package variant carries "Yes" in the RoHS column and "NIPDAU" under Lead finish/Ball material. It also meets MSL Level-1 moisture sensitivity classification with unlimited floor life at ≤30°C/60% RH.
SN74BCT640DWRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74BCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Transceiver, 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
SN74BCT640DWRG4 FAQ
1.How can I place an order for SN74BCT640DWRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74BCT640DWRG4 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 SN74BCT640DWRG4 reliable?
The price and inventory of SN74BCT640DWRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74BCT640DWRG4 is usually 5 days.
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4.How is shipping managed for SN74BCT640DWRG4?
SN74BCT640DWRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74BCT640DWRG4 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 SN74BCT640DWRG4?
For technical support, including SN74BCT640DWRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74BCT640DWRG4 requirements.
6.How does Aetrix verify that SN74BCT640DWRG4 is sourced from the original manufacturer or authorized distributors?
All SN74BCT640DWRG4 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 SN74BCT640DWRG4 meets industry standards.
7.What is the process for return or replacement of SN74BCT640DWRG4?
All SN74BCT640DWRG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74BCT640DWRG4, 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 SN74BCT640DWRG4 part is unused and in its original packaging.
Return procedure for SN74BCT640DWRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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