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Texas Instruments CY74FCT399CTSOCT
- Part No.:
- CY74FCT399CTSOCT
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CY74FCT399CTSOCT.pdf
- Description:
- IC MULTIPLEXER 4 X 1:1 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,692
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Product details
Overview
CY74FCT399CTSOCT from Texas Instruments is a high-speed quad 2-input register IC with noninverted outputs, TTL-compatible logic levels, 6.1 ns propagation delay (tPLH/tPHL), 64 mA sink / 32 mA source drive capability, and Ioff partial-power-down support. It selects four bits of data from two independent sources under a common select (S) input and latches them synchronously on the rising edge of CP - used in bus multiplexing, data routing, and register staging in industrial control and legacy computing systems.
For engineers reviewing the CY74FCT399CTSOCT datasheet, CY74FCT399CTSOCT pinout, CY74FCT399CTSOCT application, or CY74FCT399CTSOCT equivalent, key selection criteria include its 16-pin SOIC (DW) package, –40°C to 85°C operating range, FCT-family timing compatibility, Ioff-enabled power sequencing, and dual-source synchronous register function.
Technical Context
The CY74FCT399CTSOCT implements four independent D-type flip-flop channels, each selecting between two data inputs (I0X/I1X) via a shared S control line and registering output on the rising edge of CP. Its edge-triggered architecture ensures deterministic setup/hold timing (tsu = 8.5 ns for S, 3.5 ns for data; th = 1 ns for data).
It features FCT-family electrical characteristics: VOH ≈ 3.3 V (typical at IOH = –15 mA), VOL ≤ 0.55 V (at IOL = 64 mA), matched rise/fall times, and edge-rate control circuitry to suppress switching noise. Ioff disables outputs when VCC = 0 V, preventing backflow current during partial power-down.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay | 6.1 ns max (tPLH/tPHL), enabling reliable operation up to ~160 MHz clock rates in registered paths. |
| Output Drive | 64 mA sink / 32 mA source per output, sufficient to directly drive multiple TTL loads or legacy bus stubs. |
| Supply Voltage | 4.75 V to 5.25 V - tightly regulated 5 V operation required; not 3.3 V tolerant. |
| Ioff Support | Enables safe partial-power-down: outputs go high-impedance when VCC = 0 V, blocking reverse current flow. |
| Input Compatibility | Fully TTL-compatible VIH ≥ 2 V, VIL ≤ 0.8 V - interoperable with standard 5 V logic families without level shifters. |
| ESD Rating | 2000-V HBM, 200-V MM, 1000-V CDM - meets industrial handling robustness requirements. |
Pinout & Package
Package: 16-pin SOIC (DW), 7.5 mm × 10.3 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NIPDAU lead finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (S) | Common select input | Controls source selection for all four registers: S = L → I0X routed to QX; S = H → I1X routed to QX. |
| 2 (CP) | Clock input (rising-edge triggered) | Synchronizes register update; data and S must meet tsu/th timing relative to CP↑. |
| 3–6 (I0A–I0D) | Data inputs from source 0 | Four-bit parallel input port A; stable one setup time before CP↑. |
| 7–10 (I1A–I1D) | Data inputs from source 1 | Four-bit parallel input port B; same timing constraints as I0X. |
| 11–14 (QA–QD) | Noninverted register outputs | Registered 4-bit output bus; retains state between clocks; no inversion logic. |
| 15 (VCC) | Positive supply | 5 V ± 5% supply; decoupling capacitor required near pin for noise suppression. |
| 16 (GND) | Ground reference | Return path for all I/O and internal logic; low-impedance connection critical for signal integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Quad 2-input register function | Four independent DFFs sharing one S select and one CP clock - reduces control logic vs discrete registers. |
| Edge-rate controlled outputs | Slower edge transitions reduce simultaneous switching noise (SSN), easing EMI compliance in dense PCB layouts. |
| Ioff partial-power-down | Outputs enter high-Z when VCC = 0 V - enables hot-swap, power-gating, and mixed-voltage system sequencing. |
| TTL-compatible interface | Accepts and drives standard 5 V TTL logic levels without external biasing or translation. |
| Matched tPLH/tPHL | Ensures symmetrical timing margins across rising/falling edges - simplifies setup/hold analysis in synchronous designs. |
Applications
| Industrial Bus Multiplexer | Legacy System Data Staging |
|---|---|
|
Use Scenario: Selecting between two sensor data streams (e.g., primary/backup analog front-ends) before feeding into a shared ADC interface in PLC I/O modules. IC Role / Device Role / Timing Role: Quad register acts as synchronized 4-bit data selector and hold latch, isolating source switching transients from downstream logic. Use Value: Eliminates metastability risk by ensuring only clock-aligned, stable data passes - critical for deterministic scan-cycle timing in real-time control. |
Use Scenario: Buffering and aligning instruction/data fetches between dual memory banks (ROM/RAM) in retro-computing or embedded microcontroller bootloaders. IC Role / Device Role / Timing Role: Provides cycle-synchronized 4-bit data capture from either bank under software-controlled S line, acting as a programmable address/data gate. Use Value: Enables zero-wait-state memory access arbitration without adding clock-domain crossing logic or extra glue chips. |
| Test Equipment Signal Routing | Automated Test Fixture Control |
|
Use Scenario: Routing calibration signals between DUT ports and measurement instruments in ATE systems requiring precise timing alignment across multiple channels. IC Role / Device Role / Timing Role: Registers and forwards 4-bit test pattern words from pattern generator to DUT under synchronized CP, with S selecting stimulus or response mode. Use Value: Guarantees sub-ns skew between routed bits - essential for maintaining signal integrity in high-speed digital test vectors. |
Use Scenario: Controlling 4-bit configuration lines (e.g., DAC gain, filter cutoff, sensor bias) in production test jigs where settings must persist across power cycles or reset events. IC Role / Device Role / Timing Role: Acts as a synchronous latch holding fixture configuration until next CP edge, decoupling slow host MCU writes from fast test execution. Use Value: Prevents transient glitches on control lines during reconfiguration - avoids false triggering or device damage during automated testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad 2-input register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY74FCT399ATSOC | Slower 7 ns propagation delay; identical pinout, Ioff, and logic function. | Lower maximum clock frequency; suitable for cost-sensitive, lower-speed legacy upgrades. | Select when timing margin allows relaxed delay or when tube packaging is preferred over tape-and-reel. |
| SN74FCT399CTSOCT | Same speed grade (6.1 ns), identical electrical specs and pinout; TI's rebranded part number for same silicon. | No functional difference - direct second-source option with identical qualification and traceability. | Choose for dual-sourcing assurance or procurement flexibility without design change. |
Compared with CY74FCT399CTSOCT, the CY74FCT399ATSOC trades 1.1 ns of speed for broader availability in tube format, while SN74FCT399CTSOCT offers identical performance and form factor as a TI-branded alternative - both preserve the same 16-pin SOIC footprint, Ioff behavior, and TTL interface compatibility.
Availability
CY74FCT399CTSOCT is available at Aetrix Electronics and suitable for industrial bus multiplexing, legacy system data staging, test equipment signal routing, and automated test fixture control requiring stable component supply, long-lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for CY74FCT399CTSOCT 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 leader specializing in analog, embedded processing, and logic solutions, with decades of heritage in high-reliability 5 V logic families.
The CY74FCT399CTSOCT belongs to TI's FCT (Fast CMOS TTL-compatible) logic series, designed specifically for drop-in replacement of legacy TTL and earlier F logic in industrial, telecom, and computing infrastructure where robust 5 V operation and timing predictability are critical.
FAQ
What is the maximum clock frequency supported by CY74FCT399CTSOCT?
The CY74FCT399CTSOCT has a maximum propagation delay of 6.1 ns (tPLH/tPHL), supporting reliable operation up to approximately 160 MHz in ideal conditions. Actual usable frequency depends on board layout, load capacitance, and timing margins for setup/hold - design validation requires measuring tSU = 8.5 ns (S) and 3.5 ns (data) relative to CP↑ in the target system.
Does CY74FCT399CTSOCT support 3.3 V logic levels?
No, CY74FCT399CTSOCT is a 5 V-only device with VCC specified from 4.75 V to 5.25 V. Its inputs require TTL-compatible thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V), and outputs swing to ~3.3 V (VOH typ) or ~0.4 V (VOL max) - it is not 3.3 V tolerant and must be used in 5 V systems or with level-shifting interfaces.
How does Ioff functionality work in CY74FCT399CTSOCT?
In CY74FCT399CTSOCT, the Ioff circuitry disables all outputs and places them in high-impedance state when VCC = 0 V - even if input or output pins are driven externally. This prevents damaging current backflow during partial power-down, hot-swap, or mixed-voltage sequencing, making it suitable for systems with staged power-up/down sequences.
Is CY74FCT399CTSOCT pin-compatible with other FCT-series registers?
Yes, CY74FCT399CTSOCT is functionally and physically pin-compatible with CY74FCT399ATSOC and SN74FCT399CTSOCT - all share identical 16-pin SOIC (DW) footprint, pin assignments, and logic behavior. Differences are limited to speed grade (6.1 ns vs 7 ns) and branding; no PCB changes are needed for substitution within the same speed bin.
What are the thermal limitations of CY74FCT399CTSOCT in continuous operation?
CY74FCT399CTSOCT has a thermal impedance θJA of 57°C/W and is rated for ambient temperatures from –40°C to +85°C. Under worst-case static loading (e.g., all outputs sinking 64 mA), power dissipation may reach ~120 mW - adequate heatsinking and proper PCB copper pour are recommended to maintain junction temperature below 125°C, especially in enclosed or high-density assemblies.
CY74FCT399CTSOCT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74FCT
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Multiplexer
- Circuit:
- 4 x 1:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- 32mA, 64mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
CY74FCT399CTSOCT FAQ
1.How can I place an order for CY74FCT399CTSOCT through Aetrix?
Please submit a Request for Quotation (RFQ) for CY74FCT399CTSOCT 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 CY74FCT399CTSOCT reliable?
The price and inventory of CY74FCT399CTSOCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY74FCT399CTSOCT is usually 5 days.
3.What payment methods are accepted for CY74FCT399CTSOCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY74FCT399CTSOCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY74FCT399CTSOCT?
CY74FCT399CTSOCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY74FCT399CTSOCT 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 CY74FCT399CTSOCT?
For technical support, including CY74FCT399CTSOCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY74FCT399CTSOCT requirements.
6.How does Aetrix verify that CY74FCT399CTSOCT is sourced from the original manufacturer or authorized distributors?
All CY74FCT399CTSOCT 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 CY74FCT399CTSOCT meets industry standards.
7.What is the process for return or replacement of CY74FCT399CTSOCT?
All CY74FCT399CTSOCT units undergo pre-shipment inspection (PSI). If there is an issue with CY74FCT399CTSOCT, 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 CY74FCT399CTSOCT part is unused and in its original packaging.
Return procedure for CY74FCT399CTSOCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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