My Inquiry
My Account
Texas Instruments SN74LS368AD
- Part No.:
- SN74LS368AD
- Manufacturer:
- Texas Instruments
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74LS368AD.pdf
- Description:
- IC BUFFER INVERT 5.25V 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:161
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74LS368AD from Texas Instruments is a dual 4-bit inverting line driver with three-state outputs, designed for bus-oriented bidirectional data transmission in TTL-level digital systems. It features 16-pin SOIC packaging, operates from 0°C to 70°C, supports 3.5 mA output sink current, and provides high-impedance (Hi-Z) output control via two independent enable inputs - used in industrial control backplanes and legacy instrumentation interfaces.
For engineers reviewing the SN74LS368AD datasheet, SN74LS368AD pinout, SN74LS368AD application, or SN74LS368AD equivalent, key selection criteria include its dual 4-bit inverting buffer architecture, active-low 3-state enable logic, guaranteed TTL-compatible input thresholds, and SOIC-16 RoHS-compliant packaging with NIPDAU lead finish.
Technical Context
The SN74LS368AD implements two independent 4-bit inverting buffers, each with separate active-low output-enable (OE) controls (pins 1 and 15), allowing selective tri-state management of two 4-bit data paths. Its internal circuitry uses standard bipolar TTL design with Schottky-clamped transistors to limit saturation delay and ensure fast switching.
Each output delivers −3.5 mA (sink) / 0.25 mA (source) drive capability under VCC = 5 V, meeting LS-TTL voltage and current specifications. Input thresholds are fixed at VIL ≤ 0.8 V and VIH ≥ 2.0 V, ensuring compatibility with standard TTL logic families without level translation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | LS-TTL - ensures interoperability with legacy 74LS-series components and predictable noise margins. |
| Function | Dual 4-bit inverting line driver with 3-state outputs - enables bidirectional bus arbitration using two independent OE controls. |
| Supply Voltage | 4.75 V to 5.25 V - tight tolerance required for stable TTL-level operation and reliable output swing. |
| Output Drive | −3.5 mA sink / +0.25 mA source - sufficient to drive 10 LS-TTL loads per output without external buffering. |
| Propagation Delay | 25 ns max (tPLH/tPHL) - supports synchronous data rates up to ~20 MHz in point-to-point configurations. |
| Operating Temperature | 0°C to 70°C - commercial-grade rating suitable for office, lab, and non-military embedded environments. |
| Package | SOIC-16 (D) - surface-mount footprint compatible with automated assembly and IPC-7351 land patterns. |
Pinout & Package
SN74LS368AD is housed in a 16-pin Small Outline Integrated Circuit (SOIC) package (package code D), measuring 10.4 mm × 5.4 mm × 2.0 mm max height, with 1.27 mm pitch and NIPDAU lead finish. It complies with JEDEC MS-012 and IPC-7351 SOP standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OE1) | Active-low output enable for Group A (pins 2–5) | Drives all four Group A outputs into high-impedance state when HIGH; enables inversion when LOW. |
| 2–5 (A1–A4) | Inverting inputs for Group A | Accept TTL-level signals; outputs on pins 10–13 are inverted complements when OE1 = LOW. |
| 6, 7, 14, 15 | GND, VCC, GND, OE2 | Ground reference (6, 14), +5 V supply (7), and active-low enable for Group B (15). |
| 8–9, 10–13 | Group B inputs (8–9, 10–11), Group A outputs (10–13) | Pins 8–9 and 10–11 are Group B inputs; pins 10–13 are Group A outputs - note shared pin numbering per TI datasheet layout. |
| 16 (B1) | Inverting input for Group B (first bit) | Input for B1; corresponding output is pin 2 (B1̅), completing Group B inversion path (pins 16, 1, 2, 3, 4, 5 → outputs 2, 3, 4, 5). |
Key Features
| Feature | Design Value |
|---|---|
| Independent 3-state control | Two separate active-low OE inputs allow concurrent or staggered bus release of two 4-bit channels - critical for arbitration in shared-data-path systems. |
| LS-TTL compatible thresholds | VIL ≤ 0.8 V and VIH ≥ 2.0 V guarantee robust noise immunity and interoperability with 74LS, 74S, and 74F logic families without interface logic. |
| Guaranteed output drive | −3.5 mA sink capability per output ensures reliable driving of 10 LS-TTL unit loads - eliminates need for external bus drivers in moderate-fanout designs. |
| SOIC-16 RoHS compliance | NIPDAU lead finish and Level-1 MSL rating support lead-free reflow assembly without moisture sensitivity concerns or special baking requirements. |
Applications
| Industrial Backplane Interface | Legacy Test Equipment Bus |
|---|---|
Use Scenario: Bidirectional data routing between microcontroller and peripheral modules on a 16-bit ISA-style backplane with shared address/data lines. IC Role / Device Role / Timing Role: Inverting 3-state buffer providing direction-controlled signal isolation and voltage-level compatibility between LS-TTL subsystems. Use Value: Enables clean bus turnaround by independently disabling each 4-bit group during read/write transitions, preventing contention and reducing signal reflection. | Use Scenario: Signal conditioning and fanout expansion in aging automated test equipment where multiple instruments share a common GPIB-adjacent parallel control bus. IC Role / Device Role / Timing Role: Level-shifting and load-driving buffer that matches vintage TTL timing budgets while supporting modern controller I/O drive limits. Use Value: Maintains sub-25 ns propagation delay across temperature, preserving setup/hold timing margins in deterministic real-time test sequencing. |
| Embedded Control Panel Interface | Repair-Replace Legacy System Module |
Use Scenario: Interfacing a CPLD-based front-panel controller to discrete LED/dip-switch banks requiring inverted logic polarity and bus-isolated updates. IC Role / Device Role / Timing Role: Polarity-inverting driver with Hi-Z capability for safe hot-swap configuration changes without system reset. Use Value: Active-low OE allows panel reconfiguration under firmware control while holding other bus segments static - no glitch propagation during state transitions. | Use Scenario: Drop-in replacement for failed SN74LS368AN in field-deployed avionics maintenance simulators operating within commercial temperature range. IC Role / Device Role / Timing Role: Pin-compatible functional substitute delivering identical logic behavior, DC specs, and AC timing as original PDIP version. Use Value: SOIC-16 footprint enables direct PCB rework using standard reflow profile (Level-1), avoiding redesign or adapter boards in time-critical repair cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar inverting 3-state buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS368AN | Same logic function and DC/AC specs, but in 16-pin PDIP package with through-hole mounting and wider operating temp range (0°C to 70°C same, but higher thermal mass). | Preferred for prototyping, manual assembly, or legacy board rework where SOIC reflow is unavailable. | Select SN74LS368AN when hand-soldering, socket-based testing, or matching original through-hole layouts is required. |
| SN74LS240N | Octal inverting 3-state buffer (8-bit vs. dual 4-bit); shares identical electrical specs but differs in channel count and pinout - not pin-compatible. | Suitable for higher-fanout applications needing single-package 8-bit buffering instead of split 4-bit groups. | Choose SN74LS240N only when consolidating two SN74LS368AD functions into one device and redesigning PCB layout. |
Compared with SN74LS368AN, the SN74LS368AD offers surface-mount reliability and automated assembly efficiency; compared with SN74LS240N, it preserves independent 4-bit group control and maintains legacy pin mapping for drop-in replacement in existing dual-bus architectures.
Availability
SN74LS368AD is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy test equipment upgrades, and embedded control panel designs requiring stable component supply and long-term obsolescence mitigation.
Supply support for SN74LS368AD 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 over 50 years of TTL and logic IC heritage.
The SN74LS368AD belongs to TI's legacy 74LS logic family, engineered specifically for backward-compatible bus interfacing, industrial control, and repair of discontinued systems relying on proven LS-TTL performance and timing.
FAQ
What is the primary logic function of the SN74LS368AD?
The SN74LS368AD is a dual 4-bit inverting line driver with independent 3-state outputs. It accepts two groups of four TTL-level inputs (A1–A4 and B1–B4), inverts each, and drives corresponding outputs only when their respective active-low output-enable (OE1/OE2) signals are asserted. This enables controlled bidirectional data flow on shared buses without contention.
Does the SN74LS368AD support 3.3 V logic levels?
No, the SN74LS368AD is strictly a 5 V LS-TTL device. Its input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) and output swing (≈0.35 V low, ≈3.4 V high at −3.5 mA) are specified only for VCC = 4.75–5.25 V. Direct connection to 3.3 V systems requires level-shifting circuitry to avoid undefined states or excessive input current.
Is the SN74LS368AD pin-compatible with the SN74LS368AN?
Yes - the SN74LS368AD (SOIC-16) and SN74LS368AN (PDIP-16) share identical pinout, logic function, DC specifications, and AC timing. The only differences are package type, thermal characteristics, and moisture sensitivity rating; both use the same internal die and are fully interchangeable at the PCB layout level with appropriate footprint adaptation.
What is the maximum clock/data rate supported by the SN74LS368AD?
The SN74LS368AD has a maximum propagation delay of 25 ns (tPLH/tPHL) under typical conditions. This supports reliable operation in synchronous systems with clock periods ≥50 ns - i.e., up to 20 MHz for edge-triggered handshaking. For robust margin in noisy environments or across temperature extremes, design for ≤12 MHz is recommended.
Can the SN74LS368AD be used in place of the SN74LS367AD?
No - the SN74LS367AD is a dual 4-bit *non-inverting* 3-state buffer, whereas the SN74LS368AD performs inversion. Swapping them without logic inversion elsewhere in the signal path will reverse data polarity and cause functional failure. They share pinout and timing but differ fundamentally in truth table behavior.
SN74LS368AD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LS
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 2, 4 (Hex)
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 2.6mA, 24mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74LS368AD FAQ
1.How can I place an order for SN74LS368AD through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS368AD 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 SN74LS368AD reliable?
The price and inventory of SN74LS368AD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS368AD is usually 5 days.
3.What payment methods are accepted for SN74LS368AD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS368AD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS368AD?
SN74LS368AD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS368AD 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 SN74LS368AD?
For technical support, including SN74LS368AD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS368AD requirements.
6.How does Aetrix verify that SN74LS368AD is sourced from the original manufacturer or authorized distributors?
All SN74LS368AD 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 SN74LS368AD meets industry standards.
7.What is the process for return or replacement of SN74LS368AD?
All SN74LS368AD units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS368AD, 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 SN74LS368AD part is unused and in its original packaging.
Return procedure for SN74LS368AD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74LS368AD 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…
