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Texas Instruments SN74BCT756N
- Part No.:
- SN74BCT756N
- Manufacturer:
- Texas Instruments
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
SN74BCT756N.pdf
- Description:
- IC BUFFER INVERT 5.5V 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,595
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Product details
Overview
SN74BCT756N from Texas Instruments is an octal buffer/driver IC with open-collector outputs, designed for memory address bus driving and clock distribution in 3-state systems. It operates at 4.5–5.5 V, delivers 64 mA sink current per output, supports 0°C to 70°C industrial temperature range, and features BiCMOS logic for low ICCZ quiescent current. Used in legacy memory subsystems and bus interface circuits.
For engineers reviewing the SN74BCT756N datasheet, SN74BCT756N pinout, SN74BCT756N application, or SN74BCT756N equivalent, this page provides verified package mapping (PDIP-20), functional truth table behavior, open-collector drive capability, thermal resistance (θJA = 67°C/W), and direct alternatives for bus driver replacement in industrial control and embedded memory designs.
Technical Context
The SN74BCT756N implements two independent 4-bit groups (1A1–1A4 / 2A1–2A4) with separate active-low output-enable controls (1OE, 2OE), enabling selective bus segment activation. Each output is open-collector, requiring external pull-up resistors for high-level assertion and supporting wired-AND logic and bus arbitration.
Its BiCMOS architecture combines bipolar input stages for high noise immunity and CMOS output stages for reduced power consumption during static states. Propagation delays are asymmetrical: tPHL (A→Y) as low as 0.5 ns typ, while tPLH reaches 10.5 ns typ at 5 V - optimized for fast enable/disable transitions over data path timing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL/CMOS systems without level-shifting. |
| Output Sink Current | 64 mA per channel - sufficient to drive 50 Ω transmission lines or multiple TTL inputs directly. |
| Propagation Delay | tPHL = 0.5–4.2 ns, tPLH = 6.2–11.3 ns - enables high-speed address buffering with predictable timing margins. |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V - TTL-compatible logic levels ensure interoperability with legacy 74-series devices. |
| Thermal Resistance | θJA = 67°C/W (PDIP) - defines maximum power dissipation limit under natural convection cooling. |
| ESD Protection | ≥2000 V HBM, ≥200 V MM - meets MIL-STD-883 requirements for handling robustness in manufacturing environments. |
Pinout & Package
SN74BCT756N uses a 20-pin plastic dual in-line package (PDIP-N), 300-mil width, through-hole mountable with 0.1-inch lead pitch. Package conforms to JEDEC MS-001 and TI's N package outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1OE, 2OE | Active-low output-enable controls for Group 1 and Group 2 - disable all outputs to high-impedance state when high. |
| 2, 4, 6, 8 | 1A1–1A4 | Group 1 non-inverting input signals - pass through to corresponding open-collector outputs when OE is low. |
| 11, 13, 15, 17 | 2A1–2A4 | Group 2 non-inverting input signals - independently controlled by 2OE for segmented bus management. |
| 18, 16, 14, 12 | 1Y1–1Y4 | Open-collector outputs for Group 1 - sink current only; require external pull-up for logic HIGH. |
| 9, 7, 5, 3 | 2Y1–2Y4 | Open-collector outputs for Group 2 - electrically isolated from Group 1 for fault containment. |
| 10 | GND | Ground reference for all internal circuitry and output current return path. |
| 20 | VCC | Positive supply rail - powers both input and output stages; decoupling capacitor required near pin. |
Key Features
| Feature | Design Value |
|---|---|
| BiCMOS process technology | Reduces ICCZ quiescent supply current versus pure bipolar designs - critical for low-power standby modes in memory controllers. |
| Independent dual-group enable | Allows time-multiplexed or partitioned bus access using 1OE/2OE - supports interleaved memory addressing schemes. |
| Open-collector outputs | Enable wired-AND bus topologies and level translation via external pull-ups - simplifies mixed-voltage system interfacing. |
| High noise immunity inputs | TTL-compatible thresholds with 0.4 V noise margin - ensures reliable operation in electrically noisy industrial environments. |
| Fast enable/disable timing | tPHL(OE→Y) = 3.4–10.3 ns - minimizes bus contention window during output state transitions. |
Applications
| Memory Address Buffering | Legacy Bus Interface |
|---|---|
Use Scenario: Driving 16-bit address buses between microprocessor and SRAM/ROM chips in industrial PLCs. IC Role / Device Role / Timing Role: Non-inverting octal buffer with group-selectable enable - isolates CPU address lines from memory load capacitance while maintaining signal integrity. Use Value: 64 mA sink capability per output ensures full fanout to 10+ TTL loads without external drivers; open-collector design allows shared bus arbitration. |
Use Scenario: Interfacing ISA-bus peripherals with 5 V logic systems requiring level-shifted or wired-OR signaling. IC Role / Device Role / Timing Role: Bus transceiver buffer with independent enable control - manages directionless data/control line sharing across multiple cards. Use Value: Dual OE pins allow dynamic segmentation of bus segments; BiCMOS speed supports ISA timing budgets up to 8 MHz. |
| Clock Distribution Network | Industrial I/O Expansion |
Use Scenario: Distributing synchronized clock signals to multiple peripheral controllers in factory automation hardware. IC Role / Device Role / Timing Role: Low-skew clock driver with open-collector outputs - enables series-terminated or parallel-terminated clock trees. Use Value: Sub-5 ns tPHL ensures minimal clock skew across 8 outputs; TTL-compatible inputs accept direct connection from oscillator modules. |
Use Scenario: Expanding GPIO count on legacy microcontrollers via parallel port expansion in HVAC control panels. IC Role / Device Role / Timing Role: General-purpose output driver for discrete relay or LED control - configured as sink driver with external pull-up. Use Value: 64 mA per channel drives electromechanical relays directly; wide VCC range accommodates aging power supplies in field-deployed equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal open-collector buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS244N | Bipolar TTL, lower drive (24 mA), higher ICC, no BiCMOS power advantage | Limited to lower-speed, lower-density bus systems due to slower propagation and higher power | Choose for cost-sensitive, non-critical legacy replacements where 24 mA sink suffices and thermal budget permits. |
| SN74ACT244N | CMOS-based, push-pull outputs (not open-collector), 24 mA drive, 5 V only | Cannot implement wired-AND or bus arbitration; requires redesign for pull-up removal and termination changes | Prefer only if replacing with push-pull topology is acceptable and system does not rely on open-collector functionality. |
Compared with SN74LS244N, SN74BCT756N offers 2.7× higher sink current and 40% lower quiescent power; compared with SN74ACT244N, it retains essential open-collector flexibility for bus-sharing architectures but trades off push-pull speed and rail-to-rail output swing.
Availability
SN74BCT756N is available at Aetrix Electronics and suitable for industrial control systems, legacy memory subsystems, and bus interface modules requiring stable component supply across extended product lifecycles.
Supply support for SN74BCT756N 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN74BCT756N belongs to TI's 74BCT logic family - engineered for high-speed, low-power bus interface applications in 5 V systems where open-collector drive and TTL compatibility are mandatory.
FAQ
What is the function of the 1OE and 2OE pins on the SN74BCT756N?
The 1OE and 2OE pins are active-low output-enable controls for two independent 4-bit groups. When pulled low, they enable the corresponding set of open-collector outputs (1Y1–1Y4 or 2Y1–2Y4); when high, those outputs enter high-impedance state. This allows SN74BCT756N to manage segmented bus access without external gating logic.
Can the SN74BCT756N be used with 3.3 V logic inputs?
No - the SN74BCT756N has TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and requires a 4.5–5.5 V supply. Direct 3.3 V inputs may not reliably register as HIGH; level-shifting or voltage translation is required before connecting to 3.3 V sources. The SN74BCT756N itself must operate at 5 V.
Does the SN74BCT756N support hot-swap or live-insertion?
No - the SN74BCT756N lacks built-in hot-swap protection features such as power-on reset, slew-rate control, or back-drive immunity. Its absolute maximum ratings specify no tolerance for powered insertion into live backplanes. System-level protection circuitry is required for safe hot-swap deployment of SN74BCT756N.
What is the maximum capacitive load the SN74BCT756N can drive reliably?
The SN74BCT756N's switching characteristics are specified with CL = 50 pF. While it can drive heavier loads, propagation delay increases and VOL rises above spec (e.g., >0.55 V) beyond 50 pF unless output current is reduced. For reliable 64 mA sinking at 0.55 V VOL, keep total load ≤50 pF - including trace, connector, and input capacitance of downstream devices.
Is there a surface-mount version of the SN74BCT756N?
Yes - the SN74BCT756DW is the SOIC-20 surface-mount equivalent of SN74BCT756N. Both share identical logic function, timing, and DC specifications; only package type (PDIP vs. SOIC), thermal resistance (67°C/W vs. 97°C/W), and mounting method differ. Pinout and electrical behavior are fully compatible.
SN74BCT756N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74BCT
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- Open Collector
- Current - Output High, Low:
- -, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
SN74BCT756N FAQ
1.How can I place an order for SN74BCT756N through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74BCT756N 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 SN74BCT756N reliable?
The price and inventory of SN74BCT756N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74BCT756N is usually 5 days.
3.What payment methods are accepted for SN74BCT756N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74BCT756N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74BCT756N?
SN74BCT756N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74BCT756N 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 SN74BCT756N?
For technical support, including SN74BCT756N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74BCT756N requirements.
6.How does Aetrix verify that SN74BCT756N is sourced from the original manufacturer or authorized distributors?
All SN74BCT756N 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 SN74BCT756N meets industry standards.
7.What is the process for return or replacement of SN74BCT756N?
All SN74BCT756N units undergo pre-shipment inspection (PSI). If there is an issue with SN74BCT756N, 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 SN74BCT756N part is unused and in its original packaging.
Return procedure for SN74BCT756N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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