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Renesas 74FCT257CTQG
- Part No.:
- 74FCT257CTQG
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
74FCT257CTQG.pdf
- Description:
- IC MULTIPLEXER 4 X 2:1 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,876
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Product details
Overview
74FCT257CTQG from Renesas Electronics (formerly IDT) is a fast CMOS quad 2-input multiplexer with 3-state outputs, designed for bus-oriented digital systems requiring high-speed data selection and output isolation. It features true TTL-compatible inputs/outputs (VOH = 3.3 V typ., VOL = 0.3 V typ.), ±15 mA/48 mA drive capability, and industrial temperature operation (–40°C to +85°C). Used in address/data multiplexing, signal routing, and bus arbitration in embedded controllers and industrial logic boards.
For engineers reviewing the 74FCT257CTQG datasheet, 74FCT257CTQG pinout, 74FCT257CTQG application, or 74FCT257CTQG equivalent, key selection criteria include its 3-state enable control (OE active-low), propagation delay ≤4.3 ns (CL = 50 pF), high-impedance output disable during power-off, and compatibility with 5 V TTL logic families in space-constrained SOIC/QSOP layouts.
Technical Context
The 74FCT257CTQG implements four independent 2:1 multiplexers sharing a common select (S) and active-low output enable (OE) input. Each channel selects between I0x and I1x inputs, driving true (non-inverting) outputs ZA–ZD. All outputs enter high-impedance state when OE is HIGH, enabling direct bus connection without external isolation.
It uses advanced dual-metal CMOS technology to achieve TTL-compatible voltage thresholds (VIH = 2.0 V min, VIL = 0.8 V max), low leakage (≤1 µA), and robust drive strength (IOL = 48 mA, IOH = –15 mA). The device meets JEDEC Standard 18 and supports live insertion via power-off disable behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply Voltage | 5.0 V ±5% - fixed single-rail operation compatible with legacy 5 V TTL systems |
| Propagation Delay (tPLH/tPHL) | ≤4.3 ns max (CL = 50 pF, RL = 500 Ω) - enables sub-200 MHz data switching in synchronous logic paths |
| Output Drive (IOL / IOH) | 48 mA sink / –15 mA source - drives multiple TTL loads or resistive termination without buffers |
| Input Leakage (IIH / IIL) | ±1 µA max - ensures stable logic levels with high-impedance source interfaces |
| High-Impedance Output Current | ±1 µA max (IOZH/IOZL) - prevents bus contention during OE assertion or power-down |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, motor drives, and factory automation environments |
| Input Capacitance (CIN) | 10 pF max - minimizes loading on upstream drivers and preserves signal edge integrity |
Pinout & Package
74FCT257CTQG is packaged in a 16-pin QSOP (Quarter-size Small Outline Package) with 0.65 mm lead pitch, RoHS-compliant and green-processed.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (S) | Select Input | Common 2:1 selector for all four channels; LOW selects I0x, HIGH selects I1x |
| 2 (I0A) | Data Input A, Source 0 | First bit of first data source; routed to ZA when S = LOW |
| 3 (GND) | Ground Reference | Primary return path for all internal logic and I/O; must be low-impedance |
| 4 (ZB) | Output B | Buffered, non-inverting output for channel B; high-impedance when OE = HIGH |
| 5 (I0B) | Data Input B, Source 0 | Second bit of first data source; routed to ZB when S = LOW |
| 6 (I1B) | Data Input B, Source 1 | Second bit of second data source; routed to ZB when S = HIGH |
| 7 (I1A) | Data Input A, Source 1 | First bit of second data source; routed to ZA when S = HIGH |
| 8 (OE) | Output Enable (Active LOW) | Global 3-state control; outputs float when HIGH, drive when LOW |
| 9 (I0C) | Data Input C, Source 0 | Third bit of first data source; routed to ZC when S = LOW |
| 10 (I1C) | Data Input C, Source 1 | Third bit of second data source; routed to ZC when S = HIGH |
| 11 (ZC) | Output C | Buffered, non-inverting output for channel C; high-impedance when OE = HIGH |
| 12 (I0D) | Data Input D, Source 0 | Fourth bit of first data source; routed to ZD when S = LOW |
| 13 (I1D) | Data Input D, Source 1 | Fourth bit of second data source; routed to ZD when S = HIGH |
| 14 (ZD) | Output D | Buffered, non-inverting output for channel D; high-impedance when OE = HIGH |
| 15 (VCC) | Positive Supply | 5 V power rail; bypassing with 0.1 µF ceramic capacitor near pin required |
| 16 (ZA) | Output A | Buffered, non-inverting output for channel A; high-impedance when OE = HIGH |
Key Features
| Feature | Design Value |
|---|---|
| TTL-compatible I/O thresholds | VIH ≥ 2.0 V, VIL ≤ 0.8 V - interoperates directly with 74LS, 74ALS, and other 5 V TTL families without level shifters |
| Live-insertion support | Outputs disable to high-Z when VCC = 0 V - allows safe hot-plug into powered backplanes or motherboards |
| Low quiescent current | ICC ≤ 1 mA max - reduces static power in always-on industrial control modules |
| JEDEC Std. 18 compliance | Fully conforms to industry-standard timing, voltage, and drive requirements for 5 V logic interface ICs |
| Industrial temperature range | –40°C to +85°C operation - validated across full range with no derating needed for thermal design |
Applications
| Industrial PLC I/O Expansion | Legacy Bus Arbitration |
|---|---|
|
Use Scenario: Adding modular digital input/output cards to programmable logic controllers where space and signal integrity are constrained. IC Role / Device Role / Timing Role: Quad 2:1 multiplexer selecting between local sensor data and backplane-sourced configuration signals under firmware control. Use Value: Enables dynamic reconfiguration of I/O mapping using a single 74FCT257CTQG per 4-bit group, reducing component count versus discrete gate solutions. |
Use Scenario: Resolving bus contention between multiple microcontrollers sharing a common 8-bit data/address bus in retrofit industrial hardware. IC Role / Device Role / Timing Role: Data-path selector isolating active masters from idle peripherals via OE-controlled 3-state outputs. Use Value: Delivers <4.3 ns propagation delay and 48 mA drive to maintain signal fidelity across 15 cm PCB traces at 20 MHz bus rates. |
| Embedded Controller Address Multiplexing | Test Equipment Signal Routing |
|
Use Scenario: Reducing pin count on microcontrollers by time-multiplexing address and data lines over shared pins (e.g., AD0–AD7). IC Role / Device Role / Timing Role: High-speed 2:1 selector toggling between address latch output and data bus under ALE control. Use Value: Supports >20 MHz multiplexing frequency with guaranteed setup/hold timing margins due to matched tPLH/tPHL characteristics. |
Use Scenario: Automated test fixtures requiring flexible routing of stimulus signals to DUT pins based on test sequence. IC Role / Device Role / Timing Role: Reconfigurable signal path element controlled by FPGA GPIO, enabling per-test vector selection. Use Value: Low input capacitance (10 pF max) and fast enable/disable times (<7 ns) minimize signal distortion and switching overhead in high-throughput ATE. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad 2-input multiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74F257N | Same logic function and pinout; higher ICC (3 mA max), slower tPLH (6 ns max), no live-insertion guarantee | Designed for general-purpose TTL systems; lacks industrial temp rating and power-off disable | Acceptable for commercial-temp, non-critical bus isolation where cost is primary driver |
| 74ACT257SCX | Higher VCC range (4.5–5.5 V), lower drive (24 mA IOL), 3.3 V tolerant inputs; not TTL-compatible | Targets mixed-voltage systems with 3.3 V control logic; requires external pull-ups for TTL-level signaling | Preferred when interfacing with ACT-family logic or when lower power consumption outweighs drive strength needs |
Compared with SN74F257N and 74ACT257SCX, the 74FCT257CTQG uniquely combines industrial temperature qualification, live-insertion capability, and full TTL compatibility at sub-5 ns speed-making it optimal for ruggedized, drop-in replacements in legacy 5 V infrastructure.
Availability
74FCT257CTQG is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy bus arbitration, and embedded controller address multiplexing requiring stable component supply across extended lifecycle programs.
Supply support for 74FCT257CTQG 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
Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and timing solutions for automotive, industrial, and infrastructure markets.
The 74FCT257CTQG belongs to Renesas' legacy FCT logic family-engineered for high-speed, low-power 5 V TTL interoperability in industrial control, communications, and computing systems requiring reliability and long-term availability.
FAQ
Is the 74FCT257CTQG still in active production?
No-the 74FCT257CTQG is marked obsolete by Renesas and is not recommended for new designs. However, Aetrix Electronics maintains verified legacy stock with full traceability and supports ongoing production runs for industrial maintenance and replacement programs through controlled allocation and lifecycle coordination.
What package type does the 74FCT257CTQG use?
The 74FCT257CTQG uses a 16-pin QSOP (Quarter-size Small Outline Package) with 0.65 mm lead pitch and green RoHS-compliant finish. This package provides compact footprint and thermal performance suitable for dense industrial PCB layouts while maintaining compatibility with standard surface-mount assembly processes.
Does the 74FCT257CTQG support live insertion?
Yes-the 74FCT257CTQG supports live insertion: its outputs enter high-impedance state when VCC = 0 V, preventing bus contention during hot-plug operations. This behavior is explicitly guaranteed in the datasheet under "Power off disable outputs" and confirmed by IOFF ≤ ±1 µA at VCC = 0 V.
Can the 74FCT257CTQG interface directly with 3.3 V logic?
No-the 74FCT257CTQG is a 5 V-only device with TTL-compatible thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V); while 3.3 V logic HIGH may register reliably, its outputs swing to 3.3 V (typ.) and are not 3.3 V tolerant. Direct interface requires level translation or pull-up networks to ensure VOL ≤ 0.4 V for 3.3 V receivers.
What is the maximum clock/data toggle rate supported by the 74FCT257CTQG?
The 74FCT257CTQG supports reliable operation up to approximately 200 MHz in data-path applications, based on its 4.3 ns max propagation delay and 7 ns max output enable/disable times. System-level timing must account for load capacitance, trace impedance, and simultaneous switching noise-but at CL = 50 pF, it sustains clean edges up to 100 MHz with margin.
74FCT257CTQG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- 74FCT
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Multiplexer
- Circuit:
- 4 x 2:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- 15mA, 48mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QSOP
74FCT257CTQG FAQ
1.How can I place an order for 74FCT257CTQG through Aetrix?
Please submit a Request for Quotation (RFQ) for 74FCT257CTQG 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 74FCT257CTQG reliable?
The price and inventory of 74FCT257CTQG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74FCT257CTQG is usually 5 days.
3.What payment methods are accepted for 74FCT257CTQG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74FCT257CTQG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74FCT257CTQG?
74FCT257CTQG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74FCT257CTQG 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 74FCT257CTQG?
For technical support, including 74FCT257CTQG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74FCT257CTQG requirements.
6.How does Aetrix verify that 74FCT257CTQG is sourced from the original manufacturer or authorized distributors?
All 74FCT257CTQG 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 74FCT257CTQG meets industry standards.
7.What is the process for return or replacement of 74FCT257CTQG?
All 74FCT257CTQG units undergo pre-shipment inspection (PSI). If there is an issue with 74FCT257CTQG, 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 74FCT257CTQG part is unused and in its original packaging.
Return procedure for 74FCT257CTQG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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