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onsemi 74ACQ543SC
- Part No.:
- 74ACQ543SC
- Manufacturer:
- onsemi
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74ACQ543SC.pdf
- Description:
- IC TXRX NON-INVERT 6V 24SOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,382
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Product details
Overview
74ACQ543SC from Fairchild Semiconductor is a non-inverting octal registered transceiver with dual-direction 3-STATE outputs, featuring separate latch enable (LEAB/LEBA) and output enable (OEAB/OEBA) controls for independent A↔B data flow management. It operates across 2.0V–6.0V supply, delivers ±24 mA output drive, and guarantees pin-to-pin skew ≤1.0 ns at VCC = 5.0V with CL = 50 pF - used in high-integrity bus interface applications such as industrial backplane data routing.
For engineers reviewing the 74ACQ543SC datasheet, pinout, applications, or equivalent options, key selection criteria include simultaneous switching noise immunity (VOLP ≤ 1.5 V, VOLV ≥ −1.2 V), dynamic input thresholds (VIHD = 2.2 V, VILD = 0.8 V @ 5.0 V), latch pulse width requirement (tW = 4.0 ns min), and SOIC-24 package compatibility with JEDEC MS-013 footprint.
Technical Context
The 74ACQ543SC integrates two independent sets of eight D-type latches - one for A-to-B and one for B-to-A data paths - each with dedicated CE (enable), LE (latch), and OE (output enable) inputs. Its Quiet Series™ architecture employs GTO™ output control, undershoot correction, and split ground bus to suppress simultaneous switching noise.
It supports transparent mode (CE LOW + LE LOW) and storage mode (CE LOW + LE HIGH-to-LOW edge), with output buffers entering high-impedance state when OE is HIGH. Propagation delays are specified for both data-path (tPLH/tPHL ≤ 11.5 ns @ 3.3 V) and control-path (LE→output ≤ 13.0 ns) operation under guaranteed load conditions.
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 systems without level shifters |
| Output Drive Strength | ±24 mA - sufficient to drive standard TTL loads and moderate-capacitance PCB traces |
| Propagation Delay (A↔B) | ≤11.5 ns @ 3.3 V, CL = 50 pF - ensures timing compliance in 20+ MHz bus clock domains |
| Output Skew | ≤1.0 ns - critical for maintaining data validity across all 8 bits during parallel transfers |
| Dynamic Input Thresholds | VIHD = 2.2 V, VILD = 0.8 V @ VCC = 5.0 V - provides 0.7 V noise margin against rail-to-rail interference |
| Quiet Output Noise | VOLP ≤ 1.5 V, VOLV ≥ −1.2 V - measured under worst-case simultaneous switching, enabling stable operation in noise-sensitive environments |
| Operating Temperature | −40°C to +85°C - qualified for industrial ambient conditions without derating |
Pinout & Package
74ACQ543SC is housed in a 24-lead Small Outline Integrated Circuit (SOIC) package per JEDEC MS-013, 0.300" wide (Package Number M24B), with standard gull-wing lead form and 1.27 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OEAB) | A-to-B Output Enable Input | Active LOW: enables B-side 3-STATE outputs only when CEAB is also LOW |
| 2 (CEAB) | A-to-B Enable Input | Active LOW: gates data flow from A inputs into A latches; disables latch updates when HIGH |
| 3 (LEAB) | A-to-B Latch Enable Input | Active LOW pulse: captures A0–A7 on falling edge; holds data when HIGH |
| 4–11 (A0–A7) | A-Side Data I/O | Inputs during A→B transfer; high-impedance outputs during B→A transfer |
| 12 (GND) | Ground Reference | Split ground bus connection for noise isolation between logic and I/O sections |
| 13 (VCC) | Power Supply | 2.0–6.0 V supply with internal decoupling support for Quiet Series™ noise suppression |
| 14–21 (B0–B7) | B-Side Data I/O | Inputs during B→A transfer; high-impedance outputs during A→B transfer |
| 22 (LEBA) | B-to-A Latch Enable Input | Active LOW pulse: captures B0–B7 on falling edge; holds data when HIGH |
| 23 (CEBA) | B-to-A Enable Input | Active LOW: gates data flow from B inputs into B latches; disables latch updates when HIGH |
| 24 (OEBA) | B-to-A Output Enable Input | Active LOW: enables A-side 3-STATE outputs only when CEBA is also LOW |
Key Features
| Feature | Design Value |
|---|---|
| Quiet Series™ Noise Suppression | GTO™ output control + undershoot corrector + split ground bus reduce simultaneous switching noise to VOLP ≤ 1.5 V and VOLV ≥ −1.2 V |
| Dual Independent Register Sets | Separate A→B and B→A latches allow concurrent bidirectional data buffering without arbitration logic |
| Full 3-STATE Output Control | Dedicated OEAB/OEBA pins enable independent tri-state control per direction, supporting shared-bus contention management |
| Guaranteed Pin-to-Pin Skew | ≤1.0 ns skew across all 8 outputs ensures setup/hold timing integrity in parallel data paths |
| Wide-Voltage Operation | 2.0–6.0 V supply range supports mixed-voltage system integration and legacy 5 V compatibility |
Applications
| Industrial Backplane Interface | Test Equipment Data Bus |
|---|---|
Use Scenario: Bidirectional data exchange between CPU module and I/O expansion cards in modular PLC chassis. IC Role / Device Role / Timing Role: Registered transceiver managing synchronized A↔B data handshaking with latch-controlled timing alignment. Use Value: Eliminates external glue logic by integrating direction control, latching, and 3-STATE buffering - reduces board area and signal routing complexity. |
Use Scenario: High-fidelity digital stimulus/response path in automated test equipment (ATE) mainframe. IC Role / Device Role / Timing Role: Octal registered buffer isolating pattern generator outputs from DUT inputs while preserving timing margins. Use Value: Quiet Series™ noise suppression prevents false triggering during simultaneous multi-bit transitions, improving test repeatability. |
| Legacy System Bus Extender | Programmable Logic Interposer |
Use Scenario: Bridging 8-bit ISA-compatible peripheral interfaces to modern microcontroller buses with voltage translation. IC Role / Device Role / Timing Role: Level-tolerant transceiver providing latch-stabilized data capture and controlled output enable sequencing. Use Value: 2.0–6.0 V operation allows direct connection to both 3.3 V MCUs and 5 V peripherals without external level shifters. |
Use Scenario: Interfacing FPGA I/O banks to external memory or sensor arrays requiring precise timing control. IC Role / Device Role / Timing Role: Registered data path synchronizing asynchronous sensor reads with FPGA clock domain using LE-driven capture. Use Value: Guaranteed 4.0 ns minimum LE pulse width and 1.5 ns setup/hold times ensure reliable capture at FPGA clock rates up to 100 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74ACTQ543SC | 5.0 V only supply (4.5–5.5 V); tighter VIH/VIL thresholds (2.0 V/0.8 V); identical pinout and function | Optimized for strict 5 V TTL systems; lower noise margin at 3.3 V operation | Select when operating exclusively at 5 V and requiring ACT-speed performance with enhanced noise immunity |
| SN74LVTH16245ADGGR | 16-bit, non-latched, 3.3 V only (2.7–3.6 V); higher drive (±32 mA); different pinout and no latch enable | Lacks register functionality; requires external clocking for data capture; suited for pure bus driving | Choose only if latch capability is unnecessary and higher bandwidth 16-bit transfer is required at 3.3 V |
Compared with 74ACQ543SC, the 74ACTQ543SC offers superior noise immunity at 5 V but sacrifices 3.3 V compatibility, while the SN74LVTH16245ADGGR provides double data width and higher drive at 3.3 V but removes latching - making 74ACQ543SC uniquely balanced for mixed-voltage, registered bidirectional bus applications.
Availability
74ACQ543SC is available at Aetrix Electronics and suitable for industrial backplane interfaces, automated test equipment data buses, legacy system bus extenders, and programmable logic interposers requiring stable component supply and long-term obsolescence management.
Supply support for 74ACQ543SC 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 mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and automotive systems.
The 74ACQ543SC belongs to Fairchild's Quiet Series™ advanced CMOS logic family, designed specifically for noise-critical bus interface applications where simultaneous switching noise must be minimized without sacrificing speed or voltage flexibility.
FAQ
What is the recommended operating voltage range for the 74ACQ543SC?
The 74ACQ543SC is rated for a supply voltage range of 2.0 V to 6.0 V, with full DC and AC specifications guaranteed across this span. At 3.3 V operation, it meets all timing and drive requirements including tPLH ≤ 11.5 ns and ±24 mA output capability - making it suitable for mixed-voltage designs interfacing 3.3 V microcontrollers with 5 V peripherals.
Does the 74ACQ543SC support true bidirectional registered data transfer?
Yes, the 74ACQ543SC implements two fully independent sets of eight D-type latches - one for A-to-B and one for B-to-A paths - each with dedicated CE, LE, and OE controls. This allows concurrent registration and 3-STATE control in both directions without conflict, enabling deterministic handshake protocols in backplane or test equipment architectures.
What package type is used for the 74ACQ543SC, and is it JEDEC-compliant?
The 74ACQ543SC uses a 24-lead Small Outline Integrated Circuit (SOIC) package designated as Package Number M24B, conforming to JEDEC MS-013 standards with 0.300" body width and 1.27 mm lead pitch. It is compatible with standard SOIC-24 footprints and reflow soldering profiles used in industrial PCB assembly.
How does the Quiet Series™ technology in the 74ACQ543SC reduce switching noise?
The 74ACQ543SC incorporates Fairchild's Quiet Series™ features: GTO™ (Glitch-Tolerant Output) control to suppress transient spikes, an undershoot corrector circuit to limit negative voltage excursions, and a physically split ground bus to isolate logic and I/O return paths. These reduce dynamic VOL noise to VOLP ≤ 1.5 V and VOLV ≥ −1.2 V under worst-case simultaneous switching.
Can the 74ACQ543SC be used as a direct replacement for the 74AC543?
No - the 74ACQ543SC is not a pin-compatible or functional drop-in replacement for the standard 74AC543. While both are octal transceivers, the 74ACQ543SC adds Quiet Series™ noise suppression, tighter skew control (≤1.0 ns), and modified dynamic input thresholds (VIHD/VILD). Its CE/LE/OE signal behavior and noise characteristics differ meaningfully, requiring validation in the target application.
74ACQ543SC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74ACQ
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- 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:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOP
74ACQ543SC FAQ
1.How can I place an order for 74ACQ543SC through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACQ543SC 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 74ACQ543SC reliable?
The price and inventory of 74ACQ543SC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACQ543SC is usually 5 days.
3.What payment methods are accepted for 74ACQ543SC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACQ543SC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACQ543SC?
74ACQ543SC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACQ543SC 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 74ACQ543SC?
For technical support, including 74ACQ543SC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACQ543SC requirements.
6.How does Aetrix verify that 74ACQ543SC is sourced from the original manufacturer or authorized distributors?
All 74ACQ543SC 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 74ACQ543SC meets industry standards.
7.What is the process for return or replacement of 74ACQ543SC?
All 74ACQ543SC units undergo pre-shipment inspection (PSI). If there is an issue with 74ACQ543SC, 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 74ACQ543SC part is unused and in its original packaging.
Return procedure for 74ACQ543SC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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