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Texas Instruments SN74F543NSR
- Part No.:
- SN74F543NSR
- Manufacturer:
- Texas Instruments
- Package:
- 24-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74F543NSR.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 24SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,606
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Product details
Overview
SN74F543NSR from Texas Instruments is an octal registered transceiver with 3-state outputs, implementing dual-directional data flow via independent A-to-B and B-to-A latch-enable and output-enable controls. It features true 3-state outputs, back-to-back D-type latches for bidirectional storage, A-side sink capability of 24 mA, B-side sink capability of 64 mA, and operates across 0°C to 70°C.
For engineers reviewing the SN74F543NSR datasheet, SN74F543NSR pinout, SN74F543NSR application, or SN74F543NSR equivalent, this page delivers verified functional architecture, timing parameters (e.g., tPLH ≤ 8.5 ns), absolute maximum ratings (VCC up to 7 V), output drive strength per port, and package-specific mechanical data for SSOP-24 (DB) and SOIC-24 (DW) variants.
Technical Context
The SN74F543NSR implements two independent 8-bit latch paths - A-to-B and B-to-A - each controlled by dedicated CE, LE, and OE inputs, enabling simultaneous or isolated bidirectional data staging. Its logic uses TTL-compatible input thresholds (VIH = 2 V min, VIL = 0.8 V max) and supports 5-V operation only, with no mixed-voltage I/O capability.
It provides true 3-state output control per port group: A outputs are rated for 24 mA low-level sink, B outputs for 64 mA sink, and both support high-impedance disable under OE assertion. Timing is characterized at CL = 50 pF and RL = 500 Ω, with propagation delays (tPLH/tPHL) ranging from 2.2 ns to 12.5 ns depending on signal path and temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - Requires stable 5-V supply; operation outside this range invalidates timing and drive specs. |
| IOL (A ports) | 24 mA - Supports driving standard TTL loads or multiple 74-series inputs without buffering. |
| IOL (B ports) | 64 mA - Enables direct interface to higher-current peripherals like LED arrays or bus terminations. |
| tPLH / tPHL | 2.2 ns to 12.5 ns - Specifies worst-case propagation delay from latch enable or OE to output transition under full load. |
| Operating Temp | 0°C to 70°C - Commercial-grade rating; not qualified for extended industrial or automotive temperature ranges. |
| Input Thresholds | VIH ≥ 2 V, VIL ≤ 0.8 V - Ensures reliable recognition of TTL logic levels; incompatible with CMOS-level signaling without level translation. |
| Output Disable Time | tPZL ≤ 12 ns - Critical for bus arbitration timing when releasing control of shared data lines. |
Pinout & Package
SN74F543NSR is packaged in a 24-pin SOIC (DW) body with 300-mil width, 1.27 mm pitch, and gull-wing leads. The package conforms to JEDEC MS-013 and TI's DW drawing, with thermal pad omitted and moisture sensitivity level (MSL) 1 (unlimited floor life at ≤30°C/60% RH).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8 | A1–A8 inputs/outputs | 8-bit data port A; bidirectional I/O with 3-state control via OEAB/OEBA and latch control via LEAB/LEBA. |
| 9–16 | B1–B8 inputs/outputs | 8-bit data port B; higher-drive (64 mA) side used for bus-driving or peripheral interfacing. |
| 17, 18 | LEAB, LEBA | Latch-enable signals - low-to-high transition captures data into respective A-to-B or B-to-A registers. |
| 19, 20 | OEAB, OEBA | Output-enable signals - active-low control of 3-state drivers on A or B ports independently. |
| 21, 22 | CEAB, CEBA | Chip-enable signals - must be low to activate corresponding data path; enables gating before latch or output stages. |
| 23 | VCC | Positive supply pin - connects to 5-V rail; decoupling capacitor required within 1 cm for noise immunity. |
| 24 | GND | Ground reference - shared return for all logic and output current paths; must be low-impedance connection. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent latch paths | Enables concurrent A→B and B→A data staging without contention - essential for full-duplex bus arbitration in legacy systems. |
| Asymmetric output drive (24 mA / 64 mA) | Allows A port to serve as controller-side interface and B port as high-current bus driver - eliminates need for external buffers in many 8-bit designs. |
| True 3-state outputs with fast disable | tPZL ≤ 12 ns ensures rapid bus release, reducing contention windows in multi-master or shared-bus environments. |
| Back-to-back register architecture | Provides deterministic setup/hold timing (tsu/th ≥ 3 ns) for latch-enable-controlled data capture - simplifies synchronous design with clocked control logic. |
| TTL-compatible input thresholds | VIH = 2 V min / VIL = 0.8 V max guarantees interoperability with legacy 74LS/74F logic families without level-shifting circuitry. |
Applications
| Industrial Control Backplane | Legacy Microprocessor Bus Interface |
|---|---|
Use Scenario: Bidirectional data transfer between PLC CPU module and I/O expansion cards over a parallel backplane. IC Role / Device Role / Timing Role: SN74F543NSR acts as a registered transceiver buffering address/data lines, isolating modules while maintaining timing integrity during hot-swap events. Use Value: Dual latch paths allow simultaneous read and write staging; 64 mA B-port drive directly drives terminated backplane traces without external line drivers. | Use Scenario: Interfacing Z80 or 8085 CPU with memory-mapped peripherals using multiplexed AD bus. IC Role / Device Role / Timing Role: SN74F543NSR serves as a direction-controlled data latch and bus driver, synchronizing peripheral access with CPU control signals (RD/WR, MREQ). Use Value: Independent CE/LE/OE control enables precise timing alignment with CPU strobes; 24 mA A-port matches TTL memory load requirements. |
| Test Equipment Data Acquisition | Automated Test Fixture Controller |
Use Scenario: Capturing parallel sensor outputs and routing them to a DAQ card while simultaneously sending configuration commands back to sensors. IC Role / Device Role / Timing Role: SN74F543NSR functions as a bidirectional data register, capturing sensor data on one edge and forwarding commands on another, synchronized to system clock. Use Value: Asymmetric drive allows sensor-side (A) to meet low-power sensing interface specs while actuator-side (B) drives relay coils or display segments directly. | Use Scenario: Controlling 8-channel relay banks and reading switch status in semiconductor handler test fixtures. IC Role / Device Role / Timing Role: SN74F543NSR provides isolated, latched I/O expansion for microcontroller GPIO, with separate enable controls for safe power-up sequencing. Use Value: True 3-state outputs prevent bus contention during reset; latch-enable timing (tsu/th ≥ 3 ns) aligns cleanly with 1–2 MHz fixture controller clocks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS543N | Lower power (ICCL ≈ 40 mA vs. 125 mA), slower speed (tPLH up to 15 ns), same pinout and function. | Preferred where thermal budget or static power limits constrain use of F-family devices. | Select SN74ALS543N for lower-power legacy systems where timing margin permits 2–3 ns longer propagation. |
| SN74AS543N | Faster propagation (tPLH ≤ 5.5 ns), higher drive (IOL up to 80 mA on B port), higher ICC (150 mA), same pinout. | Suitable for high-speed bus extensions requiring tighter timing closure or heavier capacitive loads. | Choose SN74AS543N when system clock rates exceed 20 MHz or trace capacitance exceeds 75 pF. |
Compared with SN74ALS543N and SN74AS543N, the SN74F543NSR delivers balanced speed (≤12.5 ns), moderate power (125 mA ICC), and proven reliability in long-lifecycle industrial equipment - making it the default choice where compatibility with existing F-series designs is required.
Availability
SN74F543NSR is available at Aetrix Electronics and suitable for industrial control backplanes, legacy microprocessor bus interfaces, and automated test fixture controllers requiring stable component supply and long-term obsolescence management.
Supply support for SN74F543NSR 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.
The SN74F543NSR belongs to TI's 74F logic family - designed for high-speed, TTL-compatible digital systems requiring robust noise immunity, predictable timing, and backward compatibility with legacy 74-series architectures.
FAQ
What is the maximum operating voltage for SN74F543NSR?
The SN74F543NSR has an absolute maximum supply voltage of 7 V, but its recommended operating range is strictly 4.5 V to 5.5 V. Operation above 5.5 V violates the recommended conditions and may cause timing violations, increased power dissipation, or accelerated device wear. The SN74F543NSR is not rated for 3.3-V or mixed-voltage operation.
Does SN74F543NSR support bidirectional data flow without external logic?
Yes, the SN74F543NSR natively supports independent bidirectional data flow using dedicated control inputs: CEAB/LEAB/OEAB manage A-to-B transfer, while CEBA/LEBA/OEBA manage B-to-A transfer. No external gates or sequencing logic are needed - each path operates autonomously, enabling full-duplex staging in a single device.
What is the output drive capability of SN74F543NSR on port B?
The SN74F543NSR B-port outputs are characterized to sink up to 64 mA per pin under recommended operating conditions (VCC = 4.5 V, TA = 0°C to 70°C). This allows direct driving of LEDs, relays, or terminated bus lines without external buffers. Exceeding 64 mA risks violating VOL specifications or triggering internal current-limiting behavior.
Can SN74F543NSR be used in place of SN74F245?
No - the SN74F543NSR is a registered transceiver with dual latches and independent enable controls, whereas the SN74F245 is an unregistered octal bus transceiver with single-directional control. They differ in function, timing behavior, and pin compatibility. Substituting SN74F543NSR for SN74F245 introduces unintended data registration and requires redesign of control signal timing.
What package options are available for SN74F543NSR?
The SN74F543NSR is offered in SOIC-24 (DW) packaging, as indicated by the "NSR" suffix. TI also produced DB (SSOP-24) and obsolete DW variants, but SN74F543NSR specifically refers to the 24-pin narrow SOIC package with 300-mil width, RoHS-compliant NiPdAu lead finish, and MSL-1 reflow rating.
SN74F543NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74F
- Package/Case:
- 24-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 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:
- 24-SO
SN74F543NSR FAQ
1.How can I place an order for SN74F543NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74F543NSR 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 SN74F543NSR reliable?
The price and inventory of SN74F543NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74F543NSR is usually 5 days.
3.What payment methods are accepted for SN74F543NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74F543NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74F543NSR?
SN74F543NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74F543NSR 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 SN74F543NSR?
For technical support, including SN74F543NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74F543NSR requirements.
6.How does Aetrix verify that SN74F543NSR is sourced from the original manufacturer or authorized distributors?
All SN74F543NSR 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 SN74F543NSR meets industry standards.
7.What is the process for return or replacement of SN74F543NSR?
All SN74F543NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74F543NSR, 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 SN74F543NSR part is unused and in its original packaging.
Return procedure for SN74F543NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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