My Inquiry
My Account
Texas Instruments SN74ALS2242D
- Part No.:
- SN74ALS2242D
- Manufacturer:
- Texas Instruments
- Package:
- -
- Datasheet:
-
SN74ALS2242D.pdf
- Description:
- BUS TRANSCEIVER, ALS SERIES
- Quantity:
- Payment:
- Shipping:
Inventory:1,944
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ALS2242D from Texas Instruments is a dual 4-bit address/data latched transceiver with 3-state outputs, designed for bidirectional data bus interfacing in TTL-level systems. It features separate A- and B-side latches, independent output enables (OE\), and operates at VCC = 5V with typical propagation delay of 14 ns and fanout of 20 TTL loads.
For engineers reviewing the SN74ALS2242D datasheet, SN74ALS2242D pinout, SN74ALS2242D application, or SN74ALS2242D equivalent, key selection criteria include its dual-latch architecture, 3-state bus-hold capability, TTL-compatible input thresholds, and support for asynchronous bidirectional data transfer in memory-mapped I/O and microprocessor bus expansion designs.
Technical Context
The SN74ALS2242D integrates two independent 4-bit latched transceivers in a single 24-pin SOIC package. Each section provides transparent latch control (L\), output enable (OE\), and direction control (DIR) to manage data flow between A- and B-buses. Latching occurs on the falling edge of L\, and outputs enter high-impedance state when OE\ is high.
It uses Advanced Low-Power Schottky (ALS) bipolar technology, delivering lower power consumption than standard LS logic while maintaining TTL voltage levels and noise margins. Input clamping diodes and internal bus-hold circuitry prevent floating inputs when OE\ is active.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply | 5V ±5% - ensures compatibility with standard TTL bus systems and eliminates need for level-shifting circuitry. |
| Propagation Delay | 14 ns max (A-to-B or B-to-A) - supports synchronous bus timing up to ~35 MHz in tightly coupled microprocessor interfaces. |
| Output Drive | IOL = 24 mA, IOH = –1.2 mA - directly drives 20 standard TTL loads without external buffers. |
| Input Thresholds | VIL = 0.8V, VIH = 2.0V - matches legacy TTL logic families for reliable signal recognition in mixed-logic systems. |
| Power Dissipation | 19 mW per bit (typical) - enables dense PCB layouts without thermal derating in multi-transceiver bus architectures. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade industrial control and instrumentation applications. |
Pinout & Package
SN74ALS2242D is housed in a 24-pin plastic small-outline integrated circuit (SOIC) package with 300-mil body width and standard 1.27-mm pitch. Pin numbering follows JEDEC MS-012AC, with Pin 1 marked by notch or dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8 | A-side data I/O (A1–A4, B1–B4) | Bi-directional data terminals for first 4-bit transceiver; driven low/high or placed in high-Z based on DIR and OE\. |
| 9, 10, 11, 12, 13, 14, 15, 16 | B-side data I/O (A1–A4, B1–B4) | Corresponding B-bus terminals for same transceiver; latched independently from second section. |
| 17, 18, 19 | L\, OE\, DIR (Section 1) | Latch enable (active-low), output enable (active-low), and direction control (high = A→B, low = B→A). |
| 20, 21, 22 | L\, OE\, DIR (Section 2) | Independent control signals for second 4-bit transceiver; allows asynchronous operation of both sections. |
| 23 | GND | Ground reference for all logic and output stages; must be connected to system common ground plane. |
| 24 | VCC | +5V supply rail; requires local 0.1-μF ceramic decoupling capacitor placed within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit latches | Enables simultaneous but separate control of two data paths-e.g., CPU address bus and peripheral data bus-without interlock logic. |
| 3-state outputs with bus-hold | Maintains last valid logic state on A/B buses during OE\ assertion, eliminating external pull-up resistors in idle bus segments. |
| Falling-edge latch trigger | Synchronizes data capture to clock edges compatible with standard microprocessor write strobes (e.g., WR\), simplifying timing integration. |
| TTL-compatible input thresholds | Accepts direct connection to 74LS, 74F, and original 74-series outputs without interface logic or level translation. |
Applications
| Microprocessor Bus Expansion | Memory-Mapped I/O Interface |
|---|---|
Use Scenario: Expanding an 8-bit microprocessor data bus to connect multiple peripheral ICs with shared address/data lines. IC Role / Device Role / Timing Role: Bidirectional bus transceiver providing isolated, latched data path between CPU and peripherals during read/write cycles. Use Value: Eliminates bus contention via 3-state control and supports concurrent latch updates across two independent 4-bit channels. | Use Scenario: Interfacing an 8085-based controller to parallel EEPROM and GPIO expanders using multiplexed AD0–AD7 lines. IC Role / Device Role / Timing Role: Latched transceiver separating address setup from data transfer phases using DIR and L\ timing coordination. Use Value: Enables clean separation of address latching and data transfer without external glue logic or additional clock domains. |
| Legacy System Data Bridge | Industrial Control Backplane |
Use Scenario: Connecting mismatched TTL subsystems (e.g., older test equipment with 74LS logic to newer ALS-based controllers). IC Role / Device Role / Timing Role: Level- and timing-transparent bridge preserving signal integrity and setup/hold timing across technology generations. Use Value: Maintains full 14 ns propagation performance while tolerating input noise margins consistent with 74LS family specifications. | Use Scenario: Implementing modular I/O backplane in programmable logic controller (PLC) rack where modules plug into shared data/address bus. IC Role / Device Role / Timing Role: Isolating module-specific data lanes from main backplane bus using independent OE\ control per slot. Use Value: Supports hot-swap-safe bus arbitration through fast 3-state enable/disable and robust ESD-tolerant I/O structures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional latched transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AS2242N | Faster propagation delay (9 ns), higher power (35 mW/bit), AS-family drive strength. | Preferred in high-speed bus repeater designs where timing margin is critical and power budget allows. | Select SN74AS2242N only if system clock period demands sub-12 ns round-trip bus delay and thermal management supports higher dissipation. |
| SN74LS2242N | Slower delay (22 ns), lower drive (IOL = 16 mA), LS-family noise immunity and power profile. | Suitable for cost-sensitive, low-noise industrial panels where bus speed ≤ 20 MHz is acceptable. | Choose SN74LS2242N when retrofitting legacy LS-based systems and board space permits larger decoupling network for slower edge rates. |
Compared with SN74AS2242N and SN74LS2242N, the SN74ALS2242D delivers optimal balance of speed (14 ns), power (19 mW/bit), and noise margin-making it ideal for mid-speed embedded bus architectures requiring long-term component stability and drop-in compatibility with existing ALS designs.
Availability
SN74ALS2242D is available at Aetrix Electronics and suitable for microprocessor bus expansion, memory-mapped I/O interface, and industrial control backplane applications requiring stable component supply and long-term obsolescence mitigation.
Supply support for SN74ALS2242D 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 company specializing in analog and embedded processing technologies, with decades of leadership in logic device innovation.
The SN74ALS2242D belongs to TI's Advanced Low-Power Schottky (ALS) logic family, engineered for high-speed, low-power bidirectional data transfer in industrial and computing systems requiring TTL compatibility and latch synchronization.
FAQ
What logic family does the SN74ALS2242D belong to, and how does it differ from standard LS devices?
The SN74ALS2242D belongs to Texas Instruments' Advanced Low-Power Schottky (ALS) logic family. Compared to standard 74LS devices, it offers 30% lower power consumption and 35% faster propagation delay (14 ns vs. 22 ns), while retaining identical pinout, voltage thresholds, and DC characteristics. This makes SN74ALS2242D a direct upgrade path in existing LS-based designs without layout or firmware changes.
Does the SN74ALS2242D support independent control of its two 4-bit sections?
Yes, the SN74ALS2242D provides fully independent control for each 4-bit transceiver section. Section 1 uses Pins 17–19 (L1\, OE1\, DIR1), and Section 2 uses Pins 20–22 (L2\, OE2\, DIR2). This allows asynchronous latching, direction reversal, and 3-state control-enabling SN74ALS2242D to manage separate address and data buses or isolate two peripheral domains on a shared backplane.
What is the function of the DIR pin on the SN74ALS2242D, and how does it affect data flow?
The DIR (direction) pin on the SN74ALS2242D determines real-time data flow direction between A- and B-buses. When DIR is high, data transfers from A-side to B-side; when low, data flows from B-side to A-side. This control operates concurrently with L\ and OE\, allowing SN74ALS2242D to dynamically switch direction mid-bus cycle-critical for protocols like Intel-style memory reads/writes where address and data share physical lines.
Is the SN74ALS2242D compatible with 3.3V logic systems?
No, the SN74ALS2242D is strictly a 5V TTL device with VCC = 5V ±5% and input thresholds defined for 0.8V/2.0V. It lacks 3.3V-tolerant inputs or dual-supply capability. Direct connection to 3.3V systems risks overvoltage damage or unreliable switching. For mixed-voltage designs, SN74ALS2242D must be used with level translators such as TXB0108 or discrete resistor-divider networks validated for SN74ALS2242D's input current specs.
What packaging options are available for the SN74ALS2242D beyond the SOIC variant?
The SN74ALS2242D is documented by Texas Instruments exclusively in the 24-pin plastic small-outline (SOIC) package (suffix 'D'). No ceramic DIP (N), CDIP (J), or TSSOP variants were released for this specific part number. Rochester Electronics' manufactured version maintains full form-fit-function compliance with the original TI SOIC-24 footprint, including lead finish, coplanarity, and thermal profile for reflow soldering.
SN74ALS2242D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- -
- Number of Elements:
- -
- Number of Bits per Element:
- -
- Input Type:
- -
- Output Type:
- -
- Current - Output High, Low:
- -
- Voltage - Supply:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SN74ALS2242D FAQ
1.How can I place an order for SN74ALS2242D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS2242D 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 SN74ALS2242D reliable?
The price and inventory of SN74ALS2242D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS2242D is usually 5 days.
3.What payment methods are accepted for SN74ALS2242D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS2242D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS2242D?
SN74ALS2242D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS2242D 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 SN74ALS2242D?
For technical support, including SN74ALS2242D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS2242D requirements.
6.How does Aetrix verify that SN74ALS2242D is sourced from the original manufacturer or authorized distributors?
All SN74ALS2242D 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 SN74ALS2242D meets industry standards.
7.What is the process for return or replacement of SN74ALS2242D?
All SN74ALS2242D units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS2242D, 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 SN74ALS2242D part is unused and in its original packaging.
Return procedure for SN74ALS2242D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ALS2242D Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
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…
