My Inquiry
My Account
Texas Instruments 8550401FA
- Part No.:
- 8550401FA
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-CFlatPack
- Datasheet:
-
8550401FA.pdf
- Description:
- 3-LINE TO 8-LINE DECODERS/DEMULT
- Quantity:
- Payment:
- Shipping:
Inventory:2,382
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
8550401FA from Texas Instruments is a military-grade 3-line to 8-line decoder/demultiplexer in CFP-16 package, operating at 4.5–5.5 V with 17 ns typical propagation delay (at 5.5 V), ±4-mA output drive, and TTL-compatible inputs. It serves as a high-speed memory decoder or data router in aerospace avionics and hardened embedded control systems where low ICC (≤80 µA) and wide temperature range (–55°C to +125°C) are critical.
For engineers reviewing the 8550401FA datasheet, 8550401FA pinout, 8550401FA application, or 8550401FA equivalent, this device is selected for deterministic decoding latency, three enable inputs (G1, G2A, G2B) enabling cascaded 24-line decoding without external inverters, and compatibility with fast-enable high-speed memories where decoder delay must remain negligible versus memory access time.
Technical Context
The 8550401FA implements a binary-select logic architecture with three active-low enable inputs (G2A, G2B) and one active-high enable (G1), allowing hierarchical expansion and demultiplexing functionality. Its internal structure routes A/B/C address bits to eight active-low outputs (Y0–Y7) only when all enables are asserted - otherwise all outputs remain high.
Designed per SN54HCT138 specifications, it uses HCMOS-compatible circuitry with TTL-level input thresholds (VIH = 2 V min, VIL = 0.8 V max) and guarantees output voltage levels of VOH ≥ 3.98 V (IOH = –4 mA) and VOL ≤ 0.26 V (IOL = 4 mA) at VCC = 4.5 V, ensuring robust noise margins in mixed-signal military platforms.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - supports standard 5-V military power rails with ±10% tolerance. |
| Propagation Delay (tpd) | 17 ns typ @ 5.5 V - enables synchronization with sub-60-ns memory access cycles. |
| Output Drive | ±4 mA @ 5 V - sufficient to directly drive 10 LSTTL loads without buffering. |
| Input Compatibility | TTL-voltage compatible - interfaces seamlessly with legacy 74LS/74ALS logic families. |
| Operating Temperature | –55°C to +125°C - qualified for extended-range military and space applications. |
| Supply Current (ICC) | 80 µA max - minimizes static power draw in always-on avionics subsystems. |
| Input Leakage | ±1 µA max - ensures stable enable/control states under high-impedance bias conditions. |
Pinout & Package
8550401FA is housed in a 16-pin Ceramic Flatpack (CFP) package measuring 10.4 mm × 5.4 mm × 2.0 mm (nominal), with gull-wing leads and metal lid hermetic sealing suitable for high-reliability environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (G2A) | Active-low enable input | Must be low to activate decoding; used with G2B and G1 for hierarchical enable control. |
| 2 (Y0) | Active-low decoded output | Asserted low when A=0,B=0,C=0 and all enables active - drives memory chip-select or peripheral select lines. |
| 3 (Y1) | Active-low decoded output | Asserted low when A=1,B=0,C=0 - provides discrete channel selection in demux mode. |
| 4 (Y2) | Active-low decoded output | Asserted low when A=0,B=1,C=0 - supports 1-of-8 routing in real-time I/O expansion. |
| 5 (Y3) | Active-low decoded output | Asserted low when A=1,B=1,C=0 - used in address decoding for dual-bank memory mapping. |
| 6 (Y4) | Active-low decoded output | Asserted low when A=0,B=0,C=1 - enables selective activation of sensor interface channels. |
| 7 (Y5) | Active-low decoded output | Asserted low when A=1,B=0,C=1 - supports interrupt vector routing in fault-tolerant controllers. |
| 8 (GND) | Ground reference | Primary return path for logic and output currents; requires low-inductance connection to system ground plane. |
| 9 (Y6) | Active-low decoded output | Asserted low when A=0,B=1,C=1 - used in redundant actuator command distribution. |
| 10 (Y7) | Active-low decoded output | Asserted low when A=1,B=1,C=1 - final output for highest-addressed peripheral or memory block. |
| 11 (C) | Binary address input | MSB of 3-bit address bus; latched on rising edge of enable assertion for synchronous decode timing. |
| 12 (B) | Binary address input | Middle bit of address bus; determines Y4–Y7 vs Y0–Y3 group selection when enables active. |
| 13 (A) | Binary address input | LSB of address bus; toggles between adjacent outputs (e.g., Y0↔Y1, Y2↔Y3) within same group. |
| 14 (G2B) | Active-low enable input | Second enable leg; both G2A and G2B must be low for decode operation - enables AND-gated control. |
| 15 (G1) | Active-high enable input | Primary enable; high state required alongside low G2A/G2B - allows polarity-flexible system-level gating. |
| 16 (VCC) | Positive supply | 5-V nominal supply rail; requires local 0.1-µF ceramic bypass capacitor placed within 3 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Three enable inputs (G1, G2A, G2B) | Enables 24-line decoding without external inverters and supports data-input demux mode via G1. |
| 17 ns typical tpd at 5.5 V | Ensures decoder delay remains below typical 25–40 ns access time of radiation-hardened SRAMs. |
| TTL-compatible inputs | Eliminates level-shifting requirements when interfacing with legacy 74LS-based flight computer buses. |
| Low ICC (≤80 µA) | Reduces standby current in always-on mission-critical subsystems such as inertial navigation monitors. |
| Hermetic CFP-16 package | Provides moisture resistance and thermal stability for operation in vacuum or high-humidity launch environments. |
Applications
| Aerospace Avionics Bus Decoding | Hardened Memory Subsystem |
|---|---|
|
Use Scenario: Address decoding for MIL-STD-1553B remote terminal interface modules requiring discrete chip-select generation across 8 peripheral registers. IC Role / Device Role / Timing Role: 3-to-8 decoder generating synchronized active-low chip-select signals with <20 ns skew across all outputs. Use Value: Enables deterministic timing alignment between bus controller commands and peripheral response windows in real-time flight control loops. |
Use Scenario: Selecting one of eight radiation-tolerant SRAM banks in a triple-modular-redundant (TMR) memory controller. IC Role / Device Role / Timing Role: High-speed memory decoder minimizing added latency between address latch and bank enable assertion. Use Value: Keeps total decode + enable delay under 30 ns, preserving >95% of SRAM's 45-ns access window for data read/write operations. |
| Launch Vehicle Telemetry MUX | Fault-Tolerant Actuator Control |
|
Use Scenario: Demultiplexing serial telemetry streams from 8 analog sensor front-ends into separate ADC channels during ascent phase. IC Role / Device Role / Timing Role: Data router using G1 as data input while A/B/C select destination channel under fixed enable condition. Use Value: Provides glitch-free channel switching with no metastability risk due to synchronous enable architecture. |
Use Scenario: Distributing fail-safe command signals to eight independent hydraulic actuator drivers in fly-by-wire systems. IC Role / Device Role / Timing Role: Safety-critical decoder asserting individual actuator enables only when all three enable conditions (G1, G2A, G2B) are validated. Use Value: Adds hardware-enforced interlock layer preventing unintended actuation during partial system resets or brownout recovery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 3-to-8 decoder applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SNJ54HCT138J | Same SN54HCT138 function but in 16-pin CDIP package; identical electrical specs and temp range (–55°C to +125°C). | Through-hole mounting; larger footprint (19.31 mm × 6.35 mm) and higher thermal resistance (RθJA = 67°C/W). | Preferred for prototyping or legacy board rework where CFP reflow capability is unavailable. |
| SNJ54HCT138FK | Same function in 20-pin LCCC package; wider body (8.89 mm × 8.45 mm), different pinout (4 corner power/ground), same performance. | Higher I/O count accommodates future expansion; requires different PCB layout and thermal pad design. | Chosen when board-level EMI immunity or multi-chip module integration demands ceramic leadless construction. |
Compared with 8550401FA, SNJ54HCT138J offers identical logic and environmental specs in through-hole form for manual assembly or legacy systems, while SNJ54HCT138FK provides enhanced mechanical ruggedness and higher pin density at the cost of layout redesign - neither is pin-compatible with the CFP-16 footprint of 8550401FA.
Availability
8550401FA is available at Aetrix Electronics and suitable for aerospace avionics bus decoding, hardened memory subsystems, launch vehicle telemetry multiplexing, and fault-tolerant actuator control requiring stable component supply across extended temperature and long-lifecycle programs.
Supply support for 8550401FA 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 high-reliability components for industrial, automotive, and defense markets.
The SN54HCT138 product line delivers military-qualified high-speed logic for mission-critical decoding and routing in environments demanding guaranteed operation from –55°C to +125°C and long-term supply stability.
FAQ
What is the maximum operating temperature range for the 8550401FA?
The 8550401FA is rated for operation from –55°C to +125°C, meeting MIL-PRF-38535 Class B requirements for extended-temperature military applications. This range is verified per SN54HCT138 specifications and confirmed in TI's packaging addendum for the CFP-16 variant. The 8550401FA maintains full electrical compliance-including propagation delay, output drive, and enable threshold behavior-across this entire range without derating.
Does the 8550401FA support demultiplexing functionality?
Yes, the 8550401FA supports demultiplexing by using the G1 enable input as a data line while holding G2A and G2B low and applying address bits to A/B/C. When G1 toggles, the selected Yx output mirrors G1's state (active-low), effectively routing a single input to one of eight outputs. This mode is explicitly documented in the SN54HCT138 functional description and confirmed in the device functional modes table for 8550401FA.
Is the 8550401FA RoHS compliant?
No, the 8550401FA uses SnPb (tin-lead) lead finish and is not RoHS compliant, as indicated in TI's packaging addendum under "RoHS" status = "No" and "Lead finish/Ball material" = "SNPB". It is intended for use in military, aerospace, and other exempt applications where leaded finishes are permitted and preferred for solder joint reliability under thermal cycling stress.
What is the recommended bypass capacitor for the 8550401FA?
Texas Instruments specifies a 0.1-µF ceramic capacitor placed as close as possible to the VCC pin (Pin 16) and GND pin (Pin 8) of the 8550401FA. This value is defined in Section 8 ("Power Supply Recommendations") of the SN54HCT138 datasheet and applies identically to the 8550401FA CFP variant. For enhanced noise suppression, TI permits paralleling with a 1-µF capacitor, but the 0.1-µF unit is mandatory for stable high-speed operation.
How many enable inputs does the 8550401FA have, and what are their polarities?
The 8550401FA has three enable inputs: G1 (active-high), G2A (active-low), and G2B (active-low). All three must be simultaneously asserted-G1 high and both G2A/G2B low-for any Yx output to respond to A/B/C inputs. This configuration is defined in the SN54HCT138 function table and verified for 8550401FA in TI's mechanical and orderable information addendum.
8550401FA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 54HCT
- Package/Case:
- 16-CFlatPack
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 3:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- 4mA, 4mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-CFP
8550401FA FAQ
1.How can I place an order for 8550401FA through Aetrix?
Please submit a Request for Quotation (RFQ) for 8550401FA 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 8550401FA reliable?
The price and inventory of 8550401FA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 8550401FA is usually 5 days.
3.What payment methods are accepted for 8550401FA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 8550401FA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 8550401FA?
8550401FA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 8550401FA 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 8550401FA?
For technical support, including 8550401FA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 8550401FA requirements.
6.How does Aetrix verify that 8550401FA is sourced from the original manufacturer or authorized distributors?
All 8550401FA 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 8550401FA meets industry standards.
7.What is the process for return or replacement of 8550401FA?
All 8550401FA units undergo pre-shipment inspection (PSI). If there is an issue with 8550401FA, 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 8550401FA part is unused and in its original packaging.
Return procedure for 8550401FA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
8550401FA Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
