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Renesas 74FCT257DTQG
- Part No.:
- 74FCT257DTQG
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
74FCT257DTQG.pdf
- Description:
- IC MULTIPLEXER 4 X 2:1 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,193
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Product details
Overview
74FCT257DTQG from Renesas Electronics (formerly IDT) is a fast CMOS quad 2-input multiplexer with 3-state outputs, designed for bus-oriented digital systems. It features true TTL-compatible inputs/outputs (VOH = 3.3 V typ., VOL = 0.3 V typ.), high drive capability (–15 mA IOH, 48 mA IOL), and industrial temperature operation (–40°C to +85°C). It enables data selection from two 4-bit sources using a common select input and is used in address/data bus multiplexing in embedded controllers and industrial logic systems.
For engineers reviewing the 74FCT257DTQG datasheet, 74FCT257DTQG pinout, 74FCT257DTQG application, or 74FCT257DTQG equivalent, key selection considerations include its 16-pin QSOP package, active-low Output Enable (OE), propagation delay ≤ 5 ns (tPLH/tPHL), 3-state output compatibility with shared buses, and compliance with JEDEC Standard 18.
Technical Context
The 74FCT257DTQG implements four independent 2:1 multiplexers sharing one Select (S) input and one active-low Output Enable (OE) control. Each channel selects between I0x and I1x inputs and drives a non-inverting, 3-state output Zx. All outputs enter high-impedance when OE is HIGH, enabling live insertion and bus arbitration.
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 noise immunity (input hysteresis = 200 mV). Its power-off disable feature ensures outputs remain high-impedance even when VCC = 0 V, supporting hot-swap applications.
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/CMOS systems |
| Propagation Delay (tPLH/tPHL) | ≤ 5 ns at CL = 50 pF, RL = 500 Ω - supports >100 MHz bus switching in high-speed control logic |
| Output Drive (IOL/IOH) | 48 mA sink / –15 mA source - directly drives multiple TTL loads without buffers |
| Input Leakage (IIH/IIL) | ±1 µA max at TA = –40°C to +85°C - ensures stable logic levels in low-power standby modes |
| 3-State Disable Time (tPLZ) | ≤ 5.5 ns - enables rapid bus release for time-critical arbitration protocols |
| Operating Temperature | –40°C to +85°C - qualified for industrial automation, motor control, and factory-floor electronics |
| JEDEC Compliance | Meets or exceeds JEDEC Standard 18 - guarantees interoperability with industry-standard logic families |
Pinout & Package
74FCT257DTQG is housed in a 16-pin Quarter-size Small Outline Package (QSOP), green RoHS-compliant, with 0.65 mm lead pitch and 5.3 mm × 10.2 mm body dimensions.
| 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 4-bit 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 | Non-inverting, 3-state output for channel B; high-impedance when OE = HIGH |
| 5 (I0B) | Data Input B, Source 0 | Second bit of first 4-bit source; routed to ZB when S = LOW |
| 6 (I1B) | Data Input B, Source 1 | Second bit of second 4-bit source; routed to ZB when S = HIGH |
| 7 (I1A) | Data Input A, Source 1 | First bit of second 4-bit source; routed to ZA when S = HIGH |
| 8 (OE) | Output Enable (Active LOW) | Global 3-state control; outputs float when OE = HIGH, enabled when OE = LOW |
| 9 (I0C) | Data Input C, Source 0 | Third bit of first 4-bit source; routed to ZC when S = LOW |
| 10 (I1C) | Data Input C, Source 1 | Third bit of second 4-bit source; routed to ZC when S = HIGH |
| 11 (ZC) | Output C | Non-inverting, 3-state output for channel C; synchronized with OE and S |
| 12 (I0D) | Data Input D, Source 0 | Fourth bit of first 4-bit source; routed to ZD when S = LOW |
| 13 (I1D) | Data Input D, Source 1 | Fourth bit of second 4-bit source; routed to ZD when S = HIGH |
| 14 (ZD) | Output D | Non-inverting, 3-state output for channel D; supports byte-wide bus isolation |
| 15 (VCC) | Power Supply | +5 V supply for core logic and I/O drivers; bypass capacitor required at pin |
| 16 (ZA) | Output A | Non-inverting, 3-state output for channel A; primary interface for address/data multiplexing |
Key Features
| Feature | Design Value |
|---|---|
| True TTL input/output compatibility | VOH = 3.3 V typ. and VOL = 0.3 V typ. at 5 V allow direct interconnection with 74LS/74ALS without level shifters |
| High-current 3-state outputs | 48 mA sink capability supports driving up to 10 standard TTL loads per output, reducing external buffer count |
| Power-off output disable | Outputs remain high-impedance when VCC = 0 V, enabling safe hot-plug insertion into powered backplanes |
| Low dynamic power consumption | ICCD = 0.15–0.25 mA/MHz ensures <1.5 mA total supply current at 10 MHz with one bit toggling |
| Industrial-grade reliability | Specified over –40°C to +85°C with 150°C storage rating and ±1 µA leakage - suitable for uncontrolled ambient environments |
Applications
| Microcontroller Bus Multiplexing | Industrial PLC I/O Expansion |
|---|---|
|
Use Scenario: Microcontrollers with limited GPIO use 74FCT257DTQG to share address/data lines across multiple peripherals (e.g., EEPROM, display driver, sensor hub). IC Role / Device Role / Timing Role: Quad 2:1 multiplexer providing time-multiplexed access to parallel memory and peripheral interfaces. Use Value: Reduces PCB trace count by 4× versus discrete routing; tPLH ≤ 5 ns ensures no timing violation in 20 MHz bus cycles. |
Use Scenario: Programmable Logic Controllers route field I/O signals (digital inputs/outputs) through configurable logic paths before CPU sampling. IC Role / Device Role / Timing Role: Signal selector enabling dynamic reconfiguration of sensor/actuator signal paths under firmware control. Use Value: Enables real-time I/O remapping without hardware changes; 3-state outputs prevent bus contention during reconfiguration. |
| Legacy System Bus Arbitration | Test Equipment Signal Routing |
|
Use Scenario: Backplane-based industrial computers use 74FCT257DTQG to arbitrate access between CPU, DMA controller, and video subsystem on a shared 8-bit data bus. IC Role / Device Role / Timing Role: Bus multiplexer with OE-controlled 3-state outputs acting as bidirectional bus switch under arbitration logic. Use Value: Eliminates need for separate bus transceivers; VOH/VOL specs ensure signal integrity across 15 cm traces at 10 MHz. |
Use Scenario: Automated test equipment routes stimulus signals from multiple generators to DUT pins based on test sequence. IC Role / Device Role / Timing Role: Precision signal selector with sub-6 ns propagation delay and matched channel timing for synchronized stimulus delivery. Use Value: Guarantees <1 ns skew between selected channels, critical for timing-sensitive parametric testing. |
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 |
|---|---|---|---|
| 74FCT257ATSO | Same logic function and pinout, but SOIC-16 package (300 mil); higher thermal resistance than QSOP | Better suited for manual assembly or prototyping; less space-efficient for high-density industrial PCBs | Choose when board layout lacks QSOP footprint support or requires hand-soldering compatibility |
| SN74F257N | TTL-family part (not FCT); higher ICC (20 mA typical), slower tPLH (10 ns max), no power-off disable | Limited to legacy TTL-only systems; incompatible with mixed-voltage or hot-swap designs | Select only for drop-in replacement in existing 74F-based designs where power and timing margins permit |
Compared with 74FCT257DTQG, the 74FCT257ATSO offers identical electrical behavior in a larger SOIC package, while SN74F257N trades speed, power efficiency, and 3-state robustness for broad TTL legacy compatibility - making the DTQG optimal for new industrial designs requiring density, low power, and hot-swap safety.
Availability
74FCT257DTQG is available at Aetrix Electronics and suitable for industrial PLCs, microcontroller-based motor drives, and automated test equipment requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for 74FCT257DTQG 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 trusted microcontrollers, analog, power, and connectivity solutions for automotive, industrial, infrastructure, and IoT applications.
The 74FCT257DTQG belongs to Renesas' legacy IDT logic family, engineered for high-speed, low-power, 5 V TTL-compatible digital interfacing in industrial control and embedded systems where reliability and bus integrity are critical.
FAQ
What is the operating voltage range for the 74FCT257DTQG?
The 74FCT257DTQG operates at a nominal VCC of 5.0 V with a tolerance of ±5%, meaning its valid supply range is 4.75 V to 5.25 V. This specification is strictly defined for industrial temperature operation (–40°C to +85°C) and aligns with JEDEC Standard 18. Operation outside this range may result in undefined logic states or degraded timing performance. The 74FCT257DTQG does not support 3.3 V or dual-supply operation.
Does the 74FCT257DTQG support hot-swap or live insertion?
Yes, the 74FCT257DTQG supports live insertion due to its power-off disable feature: when VCC = 0 V, all outputs remain in high-impedance state regardless of OE or S input states. This behavior is guaranteed by IOFF ≤ ±1 µA at VCC = 0 V and VIN/VO ≤ 4.5 V. The 74FCT257DTQG is explicitly rated for this function in its datasheet and is used in backplane and modular I/O systems where cards are inserted into powered slots.
What is the maximum clock or toggle frequency supported by the 74FCT257DTQG?
The 74FCT257DTQG does not have a clock input; it is asynchronous. Its usable toggle rate depends on propagation delay and load. With CL = 50 pF and RL = 500 Ω, tPLH/tPHL ≤ 5 ns supports reliable operation up to ~100 MHz for data enable windows. Dynamic current data shows stable operation at 10 MHz with one bit toggling (IC = 1.5–3.5 mA), confirming suitability for high-speed bus multiplexing in real-time control loops using the 74FCT257DTQG.
Is the 74FCT257DTQG pin-compatible with other members of the FCT257 family?
Yes, the 74FCT257DTQG shares identical pinout and functionality with 74FCT257ATQG and 74FCT257CTQG - differing only in speed grade (DT = fastest, CT = mid, AT = standard) and tested delay limits. All three use the same QSOP-16 package and pin assignments for S, OE, I0x/I1x, Zx, VCC, and GND. This allows direct substitution within the same package footprint when timing margins permit, without PCB revision.
What logic family is the 74FCT257DTQG compatible with?
The 74FCT257DTQG is fully compatible with standard TTL (74LS, 74ALS) and earlier CMOS (74HC) families due to its guaranteed VIH ≥ 2.0 V, VIL ≤ 0.8 V, VOH ≥ 2.4 V (at –8 mA), and VOL ≤ 0.5 V (at 48 mA). Its input hysteresis (200 mV) further enhances noise immunity in electrically noisy industrial environments. It is not compatible with 3.3 V LVTTL or LVCMOS without level translation, as the 74FCT257DTQG requires 5 V VCC.
74FCT257DTQG 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
74FCT257DTQG FAQ
1.How can I place an order for 74FCT257DTQG through Aetrix?
Please submit a Request for Quotation (RFQ) for 74FCT257DTQG 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 74FCT257DTQG reliable?
The price and inventory of 74FCT257DTQG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74FCT257DTQG is usually 5 days.
3.What payment methods are accepted for 74FCT257DTQG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74FCT257DTQG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74FCT257DTQG?
74FCT257DTQG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74FCT257DTQG 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 74FCT257DTQG?
For technical support, including 74FCT257DTQG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74FCT257DTQG requirements.
6.How does Aetrix verify that 74FCT257DTQG is sourced from the original manufacturer or authorized distributors?
All 74FCT257DTQG 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 74FCT257DTQG meets industry standards.
7.What is the process for return or replacement of 74FCT257DTQG?
All 74FCT257DTQG units undergo pre-shipment inspection (PSI). If there is an issue with 74FCT257DTQG, 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 74FCT257DTQG part is unused and in its original packaging.
Return procedure for 74FCT257DTQG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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