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NXP Semiconductors 74HC243D,118
- Part No.:
- 74HC243D,118
- Manufacturer:
- NXP Semiconductors
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
74HC243D,118.pdf
- Description:
- IC TXRX NON-INVERT 6V 14SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,809
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Product details
Overview
74HC243D,118 from NXP Semiconductors (formerly Philips) is a high-speed CMOS quad bus transceiver with non-inverting 3-state outputs in both directions, pin-compatible with LSTTL, specified per JEDEC 7A, operating from −40 °C to +125 °C, and designed for asynchronous 4-line bidirectional data transfer between isolated buses in industrial control backplanes.
For engineers reviewing the 74HC243D,118 datasheet, 74HC243D,118 pinout, 74HC243D,118 application, or 74HC243D,118 equivalent, this page delivers verified functional behavior, SO14 package details, propagation delay (6 ns typ. at 5 V/15 pF), 3-state enable timing, and direct alternatives for bus isolation upgrades in legacy TTL-compatibile systems.
Technical Context
The 74HC243D,118 implements dual independent 4-bit bidirectional data paths controlled by separate active-low output enables (OEA and OEB), enabling full bus separation without direction pins. Each transceiver channel supports true (non-inverting) signal flow in both A→B and B→A directions under valid enable conditions.
Its logic conforms to standard HC-series voltage thresholds (VIH = 3.15 V min at VCC = 4.5 V), supports 2–6 V supply operation, and delivers 6 mA sink/source drive capability while maintaining low quiescent current (≤160 µA at 6 V/−40 °C to +125 °C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.0 V to 6.0 V - Enables interoperability with 3.3 V and 5 V logic domains without level shifters. |
| Propagation Delay (An↔Bn) | 6 ns typical at VCC = 5 V, CL = 15 pF - Supports >100 MHz bus toggle rates in point-to-point configurations. |
| 3-State Enable/Disable Time | 14–28 ns max at VCC = 6 V - Ensures clean bus arbitration with minimal contention window during direction switching. |
| Output Drive Strength | ±6.0 mA at VCC = 4.5 V - Sufficient to drive 10 LSTTL loads or 50 pF transmission lines directly. |
| Input/Output Capacitance | CI = 3.5 pF, CI/O = 10 pF - Minimizes capacitive loading on shared bus traces, preserving signal integrity. |
| Operating Temperature | −40 °C to +125 °C - Qualified for under-hood automotive ECUs and industrial PLC I/O modules. |
| ESD Protection | HBM >2000 V, MM >200 V - Provides robust handling margin during board assembly and field service. |
Pinout & Package
74HC243D,118 is supplied in SO14 (SOT108-1) plastic small outline package: 14-lead, 3.9 mm body width, 1.27 mm lead pitch, surface-mount, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OEA) | Active-low output enable A | Asserting LOW enables A0–A3 ↔ B0–B3 bidirectional path; HIGH places all A-side I/Os in high-impedance state. |
| 2 (n.c.) | No connect | Internally unconnected; must remain floating or tied to GND/VCC per layout best practice - no electrical function. |
| 3–6 (A0–A3) | Bidirectional data port A | 4-bit bus segment connected to local subsystem; direction determined dynamically by OEA/OEB states. |
| 7 (GND) | Ground reference | Primary 0 V return for all internal logic and I/O circuits; requires low-inductance PCB connection. |
| 8–11 (B3–B0) | Bidirectional data port B | 4-bit bus segment connected to remote subsystem; identical electrical behavior to A-side ports. |
| 12 (n.c.) | No connect | Internally unconnected; no routing or termination required. |
| 13 (OEB) | Active-low output enable B | Asserting LOW enables B0–B3 ↔ A0–A3 path; independent of OEA for asymmetric bus control. |
| 14 (VCC) | Positive supply | Power rail for all internal logic; bypass capacitor (100 nF ceramic) required within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Non-inverting 3-state outputs | Preserves signal polarity across both directions without external inversion logic, simplifying bus protocol design. |
| Dual independent enable controls (OEA/OEB) | Allows selective isolation of A- or B-side buses - critical for hot-swap capable backplane architectures. |
| JEDEC 7A compliance | Guarantees mechanical and electrical compatibility with legacy LSTTL-based system designs. |
| Wide temperature range (−40 °C to +125 °C) | Validated operation in extended ambient environments without derating, supporting automotive and industrial deployment. |
| Low dynamic power (CPD = 26 pF) | Reduces switching power dissipation in high-frequency bus applications - PD ≈ 650 µW at 10 MHz, 5 V, 15 pF. |
Applications
| Industrial Backplane Interconnect | Legacy System Bus Extension |
|---|---|
|
Use Scenario: Isolating CPU and peripheral modules on a DIN-rail mounted PLC backplane where hot insertion must prevent bus contention. IC Role / Device Role / Timing Role: Bidirectional data bridge between two independently clocked 4-bit address/data buses, controlled by module presence detection signals driving OEA/OEB. Use Value: Eliminates need for discrete direction-control logic and level translators while maintaining full LSTTL timing compatibility. |
Use Scenario: Extending an aging 8085-based test equipment mainframe with new I/O cards using modern 3.3 V peripherals. IC Role / Device Role / Timing Role: Voltage-tolerant bus transceiver translating between 5 V motherboard and 3.3 V add-on card, leveraging 2–6 V supply flexibility. Use Value: Enables mixed-voltage expansion without redesigning power distribution or adding DC-DC converters. |
| Automotive ECU Subsystem Link | Test Equipment Signal Routing |
|
Use Scenario: Connecting microcontroller UART and CAN controller buses inside an engine control unit exposed to under-hood thermal cycling. IC Role / Device Role / Timing Role: High-reliability bidirectional data coupler with guaranteed operation up to +125 °C ambient and HBM >2000 V ESD rating. Use Value: Reduces failure risk from thermal stress and electrostatic discharge during manufacturing and field maintenance. |
Use Scenario: Configurable signal path selection in automated test equipment where multiple DUT interfaces share a common measurement bus. IC Role / Device Role / Timing Role: Electrically isolated bus switch enabling one-to-many or many-to-one routing via OEA/OEB sequencing. Use Value: Replaces mechanical relays or complex multiplexer ICs, cutting PCB area and improving switching repeatability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HC242D,653 | Inverting outputs (A→B and B→A invert polarity); otherwise identical pinout, timing, and specs. | Requires complementary logic inversion in firmware/hardware when signal polarity preservation is mandatory. | Select only if system-level inversion is acceptable or already compensated elsewhere in the signal chain. |
| SN74LVC243APWR | 3.3 V-only operation (1.65–3.6 V), lower propagation delay (3.3 ns typ), higher drive (24 mA), different pinout (TSSOP-14). | Not pin-compatible; requires PCB redesign but offers higher speed and noise immunity in pure 3.3 V systems. | Choose for new 3.3 V designs prioritizing performance over drop-in replacement; not suitable for 5 V or mixed-voltage retrofits. |
Compared with 74HC243D,118, the 74HC242D,653 provides identical mechanical and timing behavior but inverts data - requiring system-level compensation - while the SN74LVC243APWR delivers superior speed and drive in 3.3 V domains but mandates layout changes due to non-compatible pin mapping and voltage constraints.
Availability
74HC243D,118 is available at Aetrix Electronics and suitable for industrial backplane interconnect, automotive ECU subsystem linking, and legacy system bus extension requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 74HC243D,118 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
NXP Semiconductors, formerly Philips Semiconductors, is a global leader in high-performance analog and logic ICs, with core expertise in automotive, industrial, and secure connectivity solutions.
The 74HC243D,118 belongs to NXP's HC-series logic family, engineered specifically for pin-compatible migration from TTL systems while delivering CMOS power efficiency and extended temperature reliability.
FAQ
What is the maximum operating frequency supported by the 74HC243D,118?
The 74HC243D,118 does not specify a hard maximum clock frequency, but its 6 ns typical propagation delay (at 5 V/15 pF) supports reliable bidirectional data toggling up to approximately 80–100 MHz in point-to-point configurations. Actual usable frequency depends on bus loading, trace length, and termination - system-level timing analysis is required for synchronous bus implementations.
Can the 74HC243D,118 interface between 3.3 V and 5 V logic domains?
Yes - the 74HC243D,118 operates from 2.0 V to 6.0 V and accepts input voltages from 0 V to VCC. When powered at 3.3 V, it reliably interprets 5 V inputs as HIGH (VIH min = 2.1 V at VCC = 3.3 V), and its 3.3 V outputs meet 5 V TTL input thresholds. No external level-shifting circuitry is needed for basic interfacing.
How do OEA and OEB interact when both are asserted LOW simultaneously?
When both OEA and OEB are LOW, the 74HC243D,118 enables full bidirectional conduction between A0–A3 and B0–B3 ports - data passes transparently in either direction with no inversion. This mode is used for standard bus bridging where both sides actively drive and sample the same logical bus lines.
Is the 74HC243D,118 RoHS compliant and halogen-free?
Yes - the 74HC243D,118 (manufactured by NXP) meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. The SO14 package uses lead-free matte tin terminations and green molding compound, with full compliance documentation available in NXP's product change notices.
What is the recommended bypass capacitor value and placement for the 74HC243D,118?
A 100 nF X7R ceramic capacitor is recommended, placed as close as possible to the VCC (pin 14) and GND (pin 7) pins - ideally within 5 mm and connected via short, low-inductance traces. For systems with heavy bus switching, add a 1–10 µF bulk capacitor nearby to suppress supply rail droop during simultaneous output transitions.
74HC243D,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- 74HC
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Transceiver, Non-Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 7.8mA, 7.8mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SO
74HC243D,118 FAQ
1.How can I place an order for 74HC243D,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HC243D,118 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 74HC243D,118 reliable?
The price and inventory of 74HC243D,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HC243D,118 is usually 5 days.
3.What payment methods are accepted for 74HC243D,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HC243D,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HC243D,118?
74HC243D,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HC243D,118 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 74HC243D,118?
For technical support, including 74HC243D,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HC243D,118 requirements.
6.How does Aetrix verify that 74HC243D,118 is sourced from the original manufacturer or authorized distributors?
All 74HC243D,118 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 74HC243D,118 meets industry standards.
7.What is the process for return or replacement of 74HC243D,118?
All 74HC243D,118 units undergo pre-shipment inspection (PSI). If there is an issue with 74HC243D,118, 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 74HC243D,118 part is unused and in its original packaging.
Return procedure for 74HC243D,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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