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Texas Instruments CY54FCT138TDMB
- Part No.:
- CY54FCT138TDMB
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-CDIP (0.300", 7.62mm)
- Datasheet:
-
CY54FCT138TDMB.pdf
- Description:
- 1-OF-8 DECODER 16-CDIP -55 TO 12
- Quantity:
- Payment:
- Shipping:
Inventory:3,988
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Product details
Overview
CY54FCT138TDMB from Texas Instruments is a military-grade 1-of-8 binary decoder IC with three active-low enable inputs (E1, E2), one active-high enable (E3), and eight active-low outputs (O0–O7). It operates over –55°C to 125°C, delivers 32-mA sink / 12-mA source drive, and features Ioff for partial-power-down protection in mixed-voltage systems-used in aerospace avionics bus decoding and radiation-tolerant control logic.
For engineers reviewing the CY54FCT138TDMB datasheet, CY54FCT138TDMB pinout, CY54FCT138TDMB application, or CY54FCT138TDMB equivalent, key selection criteria include its CDIP-16 package, MIL-PRF-38535 compliance, 12 ns max propagation delay, Ioff-enabled hot-swap capability, and TTL-compatible input thresholds with 5-V supply operation.
Technical Context
The CY54FCT138TDMB implements a dual-enable 3-to-8 line decoder architecture with strict timing control: all outputs remain high unless E1 and E2 are low *and* E3 is high. Its edge-rate control circuitry suppresses switching noise, while matched rise/fall times ensure clean signal transitions across temperature extremes.
Designed for partial-power-down use, the Ioff circuit disables outputs when VCC = 0 V, blocking reverse current up to ±1 µA. Input hysteresis (0.2 V) improves noise immunity, and absolute maximum ratings support –0.5 V to 7 V on all pins-enabling safe interfacing with legacy 5-V TTL and mixed-supply systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5-V TTL and CMOS logic rails |
| Propagation Delay | 1.5 ns min / 12 ns max - guarantees deterministic timing in high-reliability synchronous control paths |
| Output Drive | 32 mA sink / 12 mA source - supports direct driving of multiple TTL loads without external buffers |
| Operating Temperature | –55°C to +125°C - qualified for extended-range military, aerospace, and downhole industrial applications |
| Ioff Current | ±1 µA at VCC = 0 V - prevents backfeed damage during board-level power sequencing or hot insertion |
| Input Hysteresis | 0.2 V - rejects noise on address/enable lines in electrically noisy environments (e.g., motor drives) |
| ESD Protection | 2000-V HBM, 200-V MM, 1000-V CDM - exceeds MIL-STD-883 requirements for ruggedized system integration |
Pinout & Package
Package: CDIP-16 (Ceramic Dual In-line Package), hermetically sealed, leaded, through-hole mount, RoHS-exempt (SNPB finish), MSL N/A.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (A0) | Binary address input | LSB of 3-bit address; sampled synchronously with enables to select one of eight outputs |
| 2 (A1) | Binary address input | Mid-bit of 3-bit address; determines output mapping per truth table |
| 3 (A2) | Binary address input | MSB of 3-bit address; combined with A0/A1 to decode O0–O7 |
| 4 (E1) | Enable input (active low) | Primary global disable; must be low with E2 low and E3 high for any output activation |
| 5 (E2) | Enable input (active low) | Secondary global disable; enables parallel expansion to 1-of-32 with minimal external logic |
| 6 (E3) | Enable input (active high) | Positive-enable control; allows hierarchical enable tree in multi-decoder systems |
| 7 (O7) | Active-low decoded output | Asserts low when A2A1A0 = 111 and enables satisfied - drives termination resistors or gate inputs |
| 8 (GND) | Ground reference | Power return path; requires low-inductance connection to minimize ground bounce in high-speed switching |
| 9 (VCC) | Supply voltage | +5 V nominal; bypassing with 0.1 µF ceramic capacitor near pin essential for noise suppression |
| 10 (O0) | Active-low decoded output | Asserts low when A2A1A0 = 000 - used for reset, chip-select, or interrupt assertion |
| 11 (O1) | Active-low decoded output | Asserts low when A2A1A0 = 001 - commonly assigned to peripheral #1 in memory-mapped I/O |
| 12 (O2) | Active-low decoded output | Asserts low when A2A1A0 = 010 - supports modular address decoding in distributed control units |
| 13 (O3) | Active-low decoded output | Asserts low when A2A1A0 = 011 - enables selective activation of analog front-end channels |
| 14 (O4) | Active-low decoded output | Asserts low when A2A1A0 = 100 - used in redundant sensor interface selection logic |
| 15 (O5) | Active-low decoded output | Asserts low when A2A1A0 = 101 - facilitates bank switching in radiation-hardened FPGA configuration circuits |
| 16 (O6) | Active-low decoded output | Asserts low when A2A1A0 = 110 - routes clock enables to isolated subsystems in fault-tolerant architectures |
Key Features
| Feature | Design Value |
|---|---|
| Edge-rate controlled outputs | Reduces simultaneous switching noise (SSN) by limiting di/dt - critical for EMC-compliant avionics designs |
| Ioff partial-power-down | Enables safe insertion into live backplanes without disrupting adjacent powered circuitry |
| TTL-compatible input thresholds | VIH = 2 V min / VIL = 0.8 V max - interoperates directly with legacy 5-V microcontrollers and FPGAs |
| Matched rise/fall times | Ensures symmetrical waveform edges - eliminates duty-cycle distortion in timing-critical enable chains |
| MIL-PRF-38535 qualification | Full screening per Class B or S levels - required for flight-critical and defense electronics procurement |
Applications
| Aerospace Vehicle Control | Defense Radar Signal Routing |
|---|---|
Use Scenario: Decoding command bus addresses in fly-by-wire flight control computers operating at –55°C to +125°C. IC Role / Device Role / Timing Role: CY54FCT138TDMB acts as primary address decoder for actuator driver modules, selecting one of eight servo amplifier channels per cycle. Use Value: Its 12 ns max propagation delay ensures sub-microsecond response to pilot inputs, while Ioff prevents backfeed during partial system resets. | Use Scenario: Enabling discrete RF transmit/receive paths in phased-array radar TR modules exposed to thermal cycling. IC Role / Device Role / Timing Role: CY54FCT138TDMB serves as channel selector under FPGA control, asserting active-low enables to GaN PA drivers and LNA bias controllers. Use Value: Edge-rate control minimizes radiated emissions in densely packed RF assemblies; MIL-spec packaging withstands vibration and humidity. |
| Industrial Process Safety Logic | Downhole Oilfield Instrumentation |
Use Scenario: Implementing SIL-2 safety interlock decoding in burner management systems where power sequencing must prevent false trips. IC Role / Device Role / Timing Role: CY54FCT138TDMB decodes emergency stop conditions across redundant PLC racks, gating shutdown signals to valve actuators. Use Value: Ioff blocks reverse current during brownout events; hysteresis rejects EMI from nearby motor drives during combustion cycles. | Use Scenario: Addressing sensor multiplexers in high-temperature logging tools deployed at 175°C wellbore environments (derated). IC Role / Device Role / Timing Role: CY54FCT138TDMB selects among eight pressure/temperature transducer bridges in real-time data acquisition chains. Use Value: Ceramic D-package maintains mechanical integrity and leakage performance at elevated temperatures; 32-mA drive sustains signal integrity over long twisted-pair cables. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 1-of-8 decoder applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY54FCT138TLMB | LCCC-20 package, same speed/temp specs, no pin 16 O6 - uses internal NC routing instead of dedicated O6 terminal | Preferred for surface-mount PCBs requiring hermetic sealing and higher I/O count flexibility | Select CY54FCT138TLMB when automated assembly and smaller footprint outweigh through-hole serviceability needs |
| SN74F138N | Commercial-grade (–40°C to +85°C), no Ioff, 22 mA sink, no edge-rate control - older TTL-family part | Suitable only for non-critical, benign-environment digital logic; lacks MIL qualification and power-down safety | Choose SN74F138N only for cost-sensitive prototyping where extended temperature and reliability are not required |
Compared with CY54FCT138TLMB, CY54FCT138TDMB offers through-hole serviceability and full 16-pin output access; versus SN74F138N, it adds Ioff protection, tighter timing, and military environmental robustness-making it irreplaceable in safety-critical deployments.
Availability
CY54FCT138TDMB is available at Aetrix Electronics and suitable for aerospace vehicle control, defense radar signal routing, and industrial process safety logic requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for CY54FCT138TDMB 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 U.S.-based semiconductor leader specializing in analog, embedded processing, and high-reliability logic solutions for industrial, automotive, and defense markets.
The CY54FCT138TDMB belongs to TI's military logic family designed specifically for high-integrity decoding in harsh-environment systems where failure is not an option-emphasizing radiation tolerance, thermal resilience, and power sequencing safety.
FAQ
What is the maximum propagation delay of the CY54FCT138TDMB at full military temperature range?
The CY54FCT138TDMB has a maximum propagation delay of 12 ns across its full operating range of –55°C to +125°C, measured from any address or enable input transition to corresponding output change under specified load conditions (CL = 50 pF). This value is guaranteed per MIL-PRF-38535 test flow and appears in the official TI datasheet SCCS013B.
Does the CY54FCT138TDMB support partial-power-down operation, and how is it implemented?
Yes, the CY54FCT138TDMB supports partial-power-down via its Ioff circuitry. When VCC = 0 V, all outputs are disabled and leakage is limited to ±1 µA, preventing damaging current backflow from powered sections of the system. This feature is explicitly verified in the datasheet's electrical characteristics table and is critical for hot-swap and power-domain isolation designs.
What package type and mounting style does the CY54FCT138TDMB use?
The CY54FCT138TDMB uses a CDIP-16 (Ceramic Dual In-line Package) with through-hole leads and SNPB (tin-lead) finish. It is supplied in tubes of 25 units and is RoHS-exempt per TI's packaging documentation. The package provides hermetic sealing and mechanical stability for high-reliability applications requiring manual rework or long-term storage.
How many enable inputs does the CY54FCT138TDMB have, and what are their logic polarities?
The CY54FCT138TDMB has three enable inputs: E1 and E2 are active-low, and E3 is active-high. All three must satisfy their respective logic states (E1 = L, E2 = L, E3 = H) for any output to activate. This triple-enable structure enables flexible hierarchical decoding and easy expansion to larger decoder configurations using minimal external logic.
Is the CY54FCT138TDMB compatible with standard TTL input and output voltage levels?
Yes, the CY54FCT138TDMB is fully compatible with TTL logic levels: VIH = 2 V minimum and VIL = 0.8 V maximum for inputs, and VOH ≥ 2.4 V / VOL ≤ 0.55 V for outputs under rated load. This allows direct interface with legacy 5-V microcontrollers, FPGAs, and other TTL-family devices without level-shifting circuitry.
CY54FCT138TDMB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 54FCT
- Package/Case:
- 16-CDIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 3:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- 12mA, 32mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-CDIP
CY54FCT138TDMB FAQ
1.How can I place an order for CY54FCT138TDMB through Aetrix?
Please submit a Request for Quotation (RFQ) for CY54FCT138TDMB 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 CY54FCT138TDMB reliable?
The price and inventory of CY54FCT138TDMB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY54FCT138TDMB is usually 5 days.
3.What payment methods are accepted for CY54FCT138TDMB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY54FCT138TDMB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY54FCT138TDMB?
CY54FCT138TDMB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY54FCT138TDMB 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 CY54FCT138TDMB?
For technical support, including CY54FCT138TDMB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY54FCT138TDMB requirements.
6.How does Aetrix verify that CY54FCT138TDMB is sourced from the original manufacturer or authorized distributors?
All CY54FCT138TDMB 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 CY54FCT138TDMB meets industry standards.
7.What is the process for return or replacement of CY54FCT138TDMB?
All CY54FCT138TDMB units undergo pre-shipment inspection (PSI). If there is an issue with CY54FCT138TDMB, 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 CY54FCT138TDMB part is unused and in its original packaging.
Return procedure for CY54FCT138TDMB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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