My Inquiry
My Account
onsemi SN74LS38MEL
- Part No.:
- SN74LS38MEL
- Manufacturer:
- onsemi
- Category:
- Gates and Inverters
- Package:
- -
- Datasheet:
-
SN74LS38MEL.pdf
- Description:
- IC GATE NAND
- Quantity:
- Payment:
- Shipping:
Inventory:20,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74LS38MEL from ON Semiconductor is a quad 2-input NAND buffer with open-collector outputs, designed for wired-AND logic and level translation in TTL-compatible systems. It operates at 4.75–5.25 V, delivers 24 mA sink current per output, and exhibits 18–32 ns propagation delay at 25°C with 45 pF load - used in address decoding, bus arbitration, and interrupt signal conditioning.
For engineers reviewing the SN74LS38MEL datasheet, pinout, applications, or equivalent options, key selection factors include open-collector drive capability, guaranteed 0.4 V VOL at 24 mA, −0.65 V input clamp voltage, and SOEIAJ-14 package compatibility with legacy industrial control backplanes.
Technical Context
This device implements four independent TTL-compatible NAND gates, each with an open-collector output stage enabling wired-logic configurations and interface to higher-voltage buses. Its Schottky-clamped bipolar architecture ensures low propagation delay and reduced power dissipation versus standard TTL.
The SN74LS38MEL supports guaranteed DC performance across 0–70°C ambient temperature, with input thresholds fixed at VIH = 2.0 V (min) and VIL = 0.8 V (max), and output low voltage specified at 0.4 V (max) under 24 mA sink load - critical for noise margin validation in mixed-logic systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply Voltage | 4.75–5.25 V - ensures stable operation within standard TTL rail tolerance, compatible with 5 V ±5% regulated supplies. |
| IOL Output Sink Current | 24 mA - enables direct driving of LEDs, relays, or TTL inputs without external pull-up resistors. |
| VOL Output Low Voltage | 0.4 V max @ 24 mA - guarantees >0.4 V noise margin against TTL input low threshold (0.8 V). |
| tPLH / tPHL Propagation Delay | 18–32 ns - defines maximum timing budget for synchronous address decode or interrupt response paths. |
| VIK Input Clamp Voltage | −0.65 V - protects inputs from negative transients during hot-swap or ESD events without external diodes. |
| ICC Supply Current | 12 mA max (all outputs low) - determines worst-case power rail loading in dense logic arrays. |
Pinout & Package
SN74LS38MEL uses the SOEIAJ-14 surface-mount package (Case 965), 8.55 × 3.80 mm body size, 1.27 mm lead pitch, with gull-wing leads suitable for reflow soldering on industrial PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 4, 5, 8, 9, 11, 12 | Input A/B of NAND gates | Eight total inputs across four gates; TTL-compatible thresholds enable direct connection to LS/ALS outputs. |
| 3, 6, 10, 13 | Open-collector output | Each requires external pull-up to define HIGH level; supports wired-AND, level shifting, or bus arbitration. |
| 7 | GND | Ground reference for all inputs and outputs; must be low-impedance path to minimize ground bounce. |
| 14 | VCC | +5 V supply; decoupling capacitor (0.1 µF ceramic) required within 5 mm of this pin. |
Key Features
| Feature | Design Value |
|---|---|
| Open-collector outputs | Enables wired-AND logic and interface to 12 V or 24 V buses using single external pull-up resistor per line. |
| Guaranteed 24 mA sink capability | Drives standard TTL loads directly without buffer stages, reducing component count in legacy control systems. |
| −0.65 V input clamp voltage | Prevents latch-up during negative input excursions, eliminating need for series current-limiting resistors. |
| SOEIAJ-14 package | Industry-standard footprint compatible with JEDEC MS-012, supporting automated assembly and thermal reliability up to 70°C ambient. |
Applications
| Industrial PLC I/O Expansion | Legacy Bus Arbitration |
|---|---|
Use Scenario: Adding discrete digital input channels to programmable logic controller racks using 24 V field wiring. IC Role / Device Role / Timing Role: SN74LS38MEL acts as level translator and signal conditioner, converting 24 V sinking inputs to 5 V TTL logic levels via open-collector pull-down configuration. Use Value: Eliminates need for optocouplers or dedicated level-shifter ICs, reducing BOM cost and board space in retrofit modules. | Use Scenario: Managing shared data bus access among multiple microcontrollers in an older instrumentation system. IC Role / Device Role / Timing Role: SN74LS38MEL implements wired-AND arbitration logic where any device asserting LOW blocks bus access for others. Use Value: Provides deterministic priority resolution with sub-32 ns decision latency, avoiding software-based polling delays. |
| Interrupt Signal Aggregation | TTL-Compatible Address Decoding |
Use Scenario: Combining interrupt requests from multiple peripherals into a single CPU IRQ line in embedded controllers. IC Role / Device Role / Timing Role: SN74LS38MEL serves as active-low wired-OR (via NAND inversion) to merge asynchronous interrupt sources. Use Value: Ensures <32 ns added latency between peripheral assertion and CPU recognition, preserving real-time response. | Use Scenario: Generating chip-select signals for memory-mapped peripherals in 8-bit microprocessor systems (e.g., Z80, 8085). IC Role / Device Role / Timing Role: SN74LS38MEL performs NAND-based address decoding with precise 0.4 V VOL guarantee for clean logic transitions. Use Value: Maintains >0.4 V noise margin across full temperature range, preventing spurious chip selects in electrically noisy environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NAND buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS03N | Same logic function and open-collector outputs, but DIP-14 package only; no SOEIAJ variant available. | Requires through-hole assembly; unsuitable for surface-mount production lines using SN74LS38MEL's SOEIAJ footprint. | Select when manual prototyping or legacy through-hole board repair is required. |
| SN74LS10DR | Triple 3-input NAND with totem-pole outputs - no open-collector capability; different pinout and logic structure. | Cannot perform wired-AND or level translation; limited to standard TTL fanout without external pull-ups. | Choose only if 3-input logic and push-pull drive are needed, not as drop-in replacement. |
Compared with SN74LS03N and SN74LS10DR, the SN74LS38MEL uniquely combines quad 2-input NAND logic, open-collector outputs, and SOEIAJ-14 packaging - making it irreplaceable for surface-mount wired-AND implementations requiring 24 mA sink strength and −0.65 V input clamping.
Availability
SN74LS38MEL is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy bus arbitration, and interrupt signal aggregation requiring stable component supply and long-term obsolescence management.
Supply support for SN74LS38MEL 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
ON Semiconductor (now onsemi) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and logic solutions for automotive, industrial, and cloud infrastructure markets.
The SN74LS38MEL belongs to the legacy TTL logic product line, engineered specifically for backward compatibility in industrial control, test equipment, and military-grade systems requiring proven reliability over extended temperature ranges.
FAQ
What is the maximum sink current per output of the SN74LS38MEL?
The SN74LS38MEL guarantees 24 mA sink current per open-collector output at VCC = 4.75 V and ambient temperature up to 70°C. This rating is validated under DC conditions with VOL ≤ 0.4 V, enabling direct drive of indicators, relays, or TTL inputs without external buffering. Exceeding 24 mA risks violating VOL specification and may cause thermal stress in sustained operation.
Does the SN74LS38MEL support wired-AND logic connections?
Yes, the SN74LS38MEL supports wired-AND logic via its four open-collector outputs. When multiple outputs are tied together with a single pull-up resistor, the combined node goes LOW if any output sinks current - implementing logical AND of inverted signals. This configuration is widely used in bus arbitration and interrupt merging, and requires no additional components beyond the pull-up resistor.
What package type does the SN74LS38MEL use, and is it RoHS compliant?
The SN74LS38MEL uses the SOEIAJ-14 surface-mount package (Case 965), measuring 8.55 × 3.80 mm with 1.27 mm lead pitch. Per ON Semiconductor documentation, this part is manufactured to RoHS-compliant specifications, with lead-free terminations and halogen-free molding compound - confirmed by onsemi's official product change notices dated post-2006.
Can the SN74LS38MEL operate outside the 0°C to 70°C temperature range?
No - the SN74LS38MEL is characterized and guaranteed only for 0°C to 70°C operating ambient temperature. While some units may function outside this range, parameters like VOL, tPLH/tPHL, and ICC are not tested or warranted beyond these limits. For extended temperature applications, consider modern alternatives such as the 74LVC00A or consult onsemi's industrial-grade variants.
What is the input clamp voltage specification for the SN74LS38MEL, and why does it matter?
The SN74LS38MEL specifies VIК = −0.65 V (min) at VCC = 4.75 V and IIN = −18 mA. This input clamp diode protects against negative transients during hot-swap, ESD, or inductive kickback events. It eliminates the need for external series resistors or clamping diodes in ruggedized industrial interfaces, preserving signal integrity while reducing component count and layout complexity.
SN74LS38MEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- -
- Number of Circuits:
- -
- Number of Inputs:
- -
- Features:
- -
- Voltage - Supply:
- -
- Current - Quiescent (Max):
- -
- Current - Output High, Low:
- -
- Input Logic Level - Low:
- -
- Input Logic Level - High:
- -
- Max Propagation Delay @ V, Max CL:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SN74LS38MEL FAQ
1.How can I place an order for SN74LS38MEL through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS38MEL 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 SN74LS38MEL reliable?
The price and inventory of SN74LS38MEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS38MEL is usually 5 days.
3.What payment methods are accepted for SN74LS38MEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS38MEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS38MEL?
SN74LS38MEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS38MEL 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 SN74LS38MEL?
For technical support, including SN74LS38MEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS38MEL requirements.
6.How does Aetrix verify that SN74LS38MEL is sourced from the original manufacturer or authorized distributors?
All SN74LS38MEL 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 SN74LS38MEL meets industry standards.
7.What is the process for return or replacement of SN74LS38MEL?
All SN74LS38MEL units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS38MEL, 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 SN74LS38MEL part is unused and in its original packaging.
Return procedure for SN74LS38MEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74LS38MEL Tags
-
SN74LVC1G14DBVR
Texas Instruments
-
SN74LVC1G14DCKR
Texas Instruments
-
SN74AHC1G14DBVR
Texas Instruments
-
SN74LVC1G08DBVR
Texas Instruments
-
SN74LVC1G08DCKR
Texas Instruments
-
SN74LVC1G32DCKR
Texas Instruments
-
SN74LVC1G04DBVR
Texas Instruments
.jpg)
-
74LVC1G08GW,125
Nexperia USA Inc.
-
SN74LVC1G04DCKR
Texas Instruments
-
SN74AHC1G08DBVR
Texas Instruments
-
SN74LVC1G32DBVR
Texas Instruments
-
SN74AHCT1G08DBVR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
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…
