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Texas Instruments SN74AS158NSR
- Part No.:
- SN74AS158NSR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74AS158NSR.pdf
- Description:
- IC MULTIPLEXER 4 X 2:1 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,713
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Product details
Overview
SN74AS158NSR from Texas Instruments is a high-speed 2-line-to-1-line data selector/multiplexer with inverted output logic, designed for TTL-compatible digital systems. It features four independent 2:1 multiplexed channels, buffered inputs/outputs, a common strobe (G) enable, and operates across 0°C to 70°C at 4.5–5.5 V supply. It delivers sub-11 ns propagation delay (tPHL/tPLH) on data paths and supports 20 mA sink current - ideal for address/data routing in legacy industrial controllers and test equipment.
For engineers reviewing the SN74AS158NSR datasheet, SN74AS158NSR pinout, SN74AS158NSR application, or SN74AS158NSR equivalent, this page provides verified functional specifications, validated SOP-16 package details, confirmed inverted-output behavior, and real-world timing performance under 50 pF load conditions - all critical for drop-in replacement validation and signal integrity analysis in 5 V logic systems.
Technical Context
The SN74AS158NSR implements true 2:1 multiplexing per channel using bipolar Schottky (AS) technology, with separate A/B select control and active-low strobe (G) enabling all four outputs simultaneously. Its inverted output architecture minimizes propagation delay versus non-inverting variants like SN74AS157, achieving tPHL as low as 1 ns (min) and 4.5 ns (max) on A/B→Y paths.
It uses standard TTL input thresholds (VIH = 2 V, VIL = 0.8 V), drives 20 mA low-level output current, and maintains full compatibility with 74LS/ALS logic families while offering superior speed and drive strength. No internal 3-state or open-collector functionality is present - all outputs are totem-pole.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | TTL-compatible Advanced Schottky (AS), ensuring interoperability with 74LS/ALS without level-shifting |
| Supply Voltage Range | 4.5 V to 5.5 V - matches standard 5 V rail tolerance; absolute max 7 V prevents latch-up |
| Propagation Delay (A/B → Y) | 1 ns (min) to 5 ns (max) - enables >100 MHz toggle rates in critical data-path routing |
| Output Drive Strength | 20 mA sink (IOL), −2 mA source (IOH) - sufficient to drive multiple TTL inputs or small LEDs directly |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade embedded systems and instrumentation |
| Package Type | 16-pin SOP (NS), 1.27 mm pitch, 10.4 mm × 5.3 mm footprint - compatible with automated SMT assembly |
| Input Thresholds | VIH = 2.0 V, VIL = 0.8 V - ensures noise margin ≥0.4 V in noisy industrial environments |
Pinout & Package
SN74AS158NSR is housed in a 16-pin Small Outline Package (SOP-NS), 2.00 mm maximum height, with gull-wing leads and JEDEC-standard 1.27 mm pitch. Pin 1 is marked by a beveled corner or notch; device orientation follows standard Q1 quadrant tape feed.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 5, 6, 7, 8 9, 10, 11, 12 13, 14, 15, 16 | 1A/1B, 1Y 2A/2B, 2Y 3A/3B, 3Y 4A/4B, 4Y | Four independent 2:1 multiplexer channels; each pair selects one of two inputs (A or B) to inverted output Y |
| A/B (Pin 1) | Select Control | Common 2-level select line: A/B = L routes A inputs; A/B = H routes B inputs to all Y outputs |
| G (Pin 15) | Strobe Enable | Active-low global enable: G = L enables outputs; G = H forces all Y outputs high (inverted logic) |
| VCC (Pin 16) | Power Supply | +4.5 V to +5.5 V supply; decoupling capacitor required within 10 mm of pin |
| GND (Pin 8) | Ground Reference | Signal and power return; must be low-inductance connection to minimize ground bounce |
Key Features
| Feature | Design Value |
|---|---|
| Inverted Output Logic | Eliminates need for external inverters in applications requiring complemented data paths, reducing component count and board area |
| Sub-5 ns Max Propagation Delay | Enables reliable operation in high-speed bus arbitration and real-time control loops where timing margins are tight |
| 20 mA Output Sink Capability | Directly drives up to 10 standard TTL loads or LED indicators without external buffers |
| Buffered Inputs and Outputs | Prevents loading effects between cascaded stages and improves noise immunity on long PCB traces |
| Standard SOP-16 Footprint | Supports reflow soldering and automated optical inspection (AOI); pinout identical to SN74ALS158NSR and SN74AS157NSR |
Applications
| Industrial PLC I/O Expansion | Legacy Test Equipment Signal Routing |
|---|---|
Use Scenario: Multiplexing discrete sensor inputs (limit switches, encoders) into a shared microcontroller ADC or GPIO port. IC Role / Device Role / Timing Role: 2:1 data selector routing analog/digital signals from dual-sensor banks to single acquisition path; strobe (G) synchronized to scan cycle. Use Value: Reduces microcontroller pin count by 50% per channel pair while maintaining deterministic <5 ns switching latency for jitter-sensitive motion control. | Use Scenario: Switching between calibration reference and DUT signals in automated benchtop testers. IC Role / Device Role / Timing Role: High-fidelity signal path selector with inverted output used to generate complementary test patterns for differential measurement setups. Use Value: Eliminates external inverters in pattern generation circuits, cutting propagation skew to ≤1 ns between true/complement paths. |
| Digital Audio Data Switching | Embedded System Address Bus Multiplexing |
Use Scenario: Selecting between stereo left/right audio data streams before DAC conversion in vintage audio gear. IC Role / Device Role / Timing Role: Channel-select multiplexer feeding parallel 8-bit audio words; A/B control driven by system clock divider. Use Value: Maintains sample-aligned switching with <11 ns max delay variation across all four channels, preventing inter-channel phase distortion. | Use Scenario: Sharing a single memory address bus between two peripheral controllers in resource-constrained 8-bit microsystems. IC Role / Device Role / Timing Role: Address-line selector enabling time-multiplexed access to RAM/ROM; strobe (G) tied to CPU READY signal. Use Value: Enables dual-CPU arbitration without bus contention, leveraging guaranteed 4.5 V–5.5 V operation to match legacy 5 V memory timing windows. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 2:1 multiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS158NSR | ALS family: slower (12–28 ns max delay), lower ICC (5–10 mA), same pinout and logic function | Lower speed/power trade-off suitable for cost-sensitive, non-critical timing applications | Choose when propagation delay >12 ns is acceptable and power budget is constrained |
| SN74AS157N | Non-inverting output logic; PDIP-16 package; otherwise identical AS-family specs (speed, drive, voltage) | Requires external inversion if complemented output needed; through-hole mounting only | Choose for through-hole prototyping or when true (non-inverted) output routing is required |
Compared with SN74ALS158NSR, SN74AS158NSR offers 2.5× faster propagation and higher drive strength at increased ICC; compared with SN74AS157N, it provides identical speed but inverted output logic in surface-mount SOP-16 - making it optimal for space-constrained, high-speed, complemented-data routing.
Availability
SN74AS158NSR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy test equipment signal routing, digital audio data switching, and embedded system address bus multiplexing requiring stable component supply and long-term obsolescence management.
Supply support for SN74AS158NSR 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 innovation in high-reliability digital ICs.
The SN74AS158NSR belongs to TI's Advanced Schottky TTL logic family, engineered specifically for high-speed, low-latency data routing in 5 V industrial and instrumentation systems where timing predictability and noise immunity are critical.
FAQ
What is the primary logic function of the SN74AS158NSR?
The SN74AS158NSR is a quad 2-line-to-1-line data selector/multiplexer with inverted outputs. Each of its four independent channels selects either input A or B based on the A/B control line and presents the complemented value at output Y. The global strobe (G) enables or disables all outputs simultaneously. This function is explicitly defined in the device's function table and logic diagram in the SDAS081C datasheet.
Does the SN74AS158NSR support 3-state outputs?
No, the SN74AS158NSR does not feature 3-state outputs. All outputs are standard totem-pole, actively driving high or low. When the strobe (G) is high, outputs are forced high (due to inverted logic), not placed in high-impedance state. This is confirmed by the absence of "Z" states in the function table and lack of 3-state timing parameters (e.g., tPZH, tPZL) in the switching characteristics section of the datasheet.
What is the maximum recommended operating voltage for the SN74AS158NSR?
The maximum recommended operating supply voltage for the SN74AS158NSR is 5.5 V, with an absolute maximum rating of 7 V. Operation above 5.5 V risks exceeding recommended conditions and may degrade reliability or cause permanent damage, as specified in the "Recommended Operating Conditions" and "Absolute Maximum Ratings" tables of the SDAS081C datasheet.
Can the SN74AS158NSR be used as a direct replacement for SN74ALS158NSR?
Yes, the SN74AS158NSR is pin-compatible and functionally identical to SN74ALS158NSR, including identical pinout, logic function, and inverted output behavior. However, it offers significantly faster propagation delay (≤5 ns vs. ≤28 ns) and higher output drive (20 mA vs. 8 mA), so timing and loading margins must be re-verified in the target circuit when substituting SN74AS158NSR.
What package type and dimensions does the SN74AS158NSR use?
The SN74AS158NSR uses a 16-pin Small Outline Package (SOP-NS) with 1.27 mm lead pitch, 10.4 mm × 5.3 mm body size, and 2.00 mm maximum height. Mechanical details, including land pattern and stencil design, are documented in TI's NS0016A package outline drawing and confirmed in the Package Materials Information addendum dated 10-Aug-2026.
SN74AS158NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AS
- Package/Case:
- 16-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Multiplexer
- Circuit:
- 4 x 2:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- 400µA, 8mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
SN74AS158NSR FAQ
1.How can I place an order for SN74AS158NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AS158NSR 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 SN74AS158NSR reliable?
The price and inventory of SN74AS158NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AS158NSR is usually 5 days.
3.What payment methods are accepted for SN74AS158NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AS158NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AS158NSR?
SN74AS158NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AS158NSR 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 SN74AS158NSR?
For technical support, including SN74AS158NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AS158NSR requirements.
6.How does Aetrix verify that SN74AS158NSR is sourced from the original manufacturer or authorized distributors?
All SN74AS158NSR 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 SN74AS158NSR meets industry standards.
7.What is the process for return or replacement of SN74AS158NSR?
All SN74AS158NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74AS158NSR, 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 SN74AS158NSR part is unused and in its original packaging.
Return procedure for SN74AS158NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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