SN74LS126ADG4 Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
Quad 3-state buffer and line driver in the 74LS logic family, providing four independent unidirectional channels with active-high enable control, 24 mA output sink current, and 45 pF load capacitance rating in a 14-pin SOIC package. Enables bus driving, signal isolation, and tri-state bus sharing in TTL-compatible digital systems. Used in legacy microprocessor bus expansion and industrial control logic boards.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 14
- Lifecycle
- OBSOLETE
- Datasheet
- SN74LS126ADG4 Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Quad 3-state buffer with active-high enable per channel
- 24 mA output sink current for bus driving
- Unidirectional signal path for data bus isolation
- 74LS TTL-compatible logic family
- 45 pF rated load capacitance per output
- 14-pin SOIC package for through-hole and surface-mount boards
- Independent enable control on all 4 channels
Applications
The SN74LS126ADG4 is widely used in legacy microprocessor systems, address/data bus expansion circuits, and FPGA prototype boards where multiple devices share a common TTL bus and 3-state control is needed to prevent bus contention. It also appears in industrial PLC I/O modules and embedded controller backplanes requiring reliable 5 V TTL-level bus driving with 24 mA sink capability. Memory expansion boards and peripheral interface circuits in instrumentation equipment use it for signal buffering and level isolation.
Specifications
| YTEOL | 0 |
| Control Type | ENABLE HIGH |
| Count Direction | UNIDIRECTIONAL |
| Family | LS |
| JESD-30 Code | R-PDSO-G14 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 45pF |
| Logic IC Type | BUS DRIVER |
| Max I(ol) | 0.024A |
| Number of Bits | 1 |
| Number of Functions | 4 |
| Number of Ports | 2 |
| Output Characteristics | 3-STATE |
| Output Polarity | TRUE |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP14,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TUBE |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 22mA |
| Prop. Delay@Nom-Sup | 18ns |
| Propagation Delay (tpd) | 18ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.25V |
| Supply Voltage-Min (Vsup) | 4.75V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | NICKEL PALLADIUM GOLD |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| ## SN74LS126ADG4 Alternates Showing results | Image |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| HTS Code | 8542.39.00.60 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74LS126ADG4:
Frequently Asked Questions
How does the active-high enable control of SN74LS126ADG4 support multi-device shared bus architectures?
Each of the 4 channels has an independent active-high enable input that places the output in a high-impedance state when deasserted, allowing multiple SN74LS126ADG4 devices to share a common 5 V TTL bus without contention, with only one driver enabled at a time under system logic control.
What load capacitance and sink current does SN74LS126ADG4 support, and how does this affect bus fanout design?
The SN74LS126ADG4 is rated for 45 pF load capacitance per output and provides 24 mA output sink current, supporting a fanout of approximately 10 standard LS TTL loads per channel while maintaining signal integrity at 5 V bus operating conditions in industrial and embedded control boards.
Is SN74LS126ADG4 suitable as a replacement for older DIP-package 74LS126 devices in legacy board repairs?
Yes, the SN74LS126ADG4 is electrically equivalent to the original 74LS126 with the same 4-channel 3-state buffer function, 5 V supply, and TTL logic levels, and the 14-pin SOIC package fits standard SOIC footprints, making it a direct functional substitute for legacy bus driver repairs on industrial boards.
How does SN74LS126ADG4 compare to 74HC126 for 5 V bus driving in terms of output drive strength?
The 74LS126 series provides 24 mA IOL sink current from a 5 V supply, which is higher than the typical 4 mA to 8 mA of standard 74HC126 devices, making the SN74LS126ADG4 more suitable for driving longer PCB traces or multiple TTL loads where higher drive strength and lower output impedance are needed.
Related Guides
How to Choose a 3528 SMD Indicator LED for Blue Status Lighting: Selection Guide
A practical 3528 SMD indicator LED selection guide using 150141BS73100 and related Wurth 150141 variants for blue status lighting.
Jul 5, 2026
BAS70KFILM Design Guide for Low-Leakage Signal Clamping and RF Detector Inputs
Practical BAS70KFILM design guidance for signal clamps, RF detector inputs, leakage control, capacitance, layout, and sourcing alternatives.
Jul 5, 2026
How to Choose a BAS70 Schottky Diode for Signal Clamping: Selection Guide
A practical BAS70KFILM and BAS70-family Schottky diode selection guide for signal clamping, RF detection, leakage, and topology choices.
Jul 4, 2026
AMC1202DWVR Design Guide for Isolated Current Sensing
Practical AMC1202DWVR design guide covering shunt sizing, isolation layout, input filtering, ADC scaling, and sourcing choices.
Jul 4, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.”