SN74AHCT138DIn StockTexas Instruments
SN74AHCT138D is a 3-line to 8-line decoder/demultiplexer IC with inverting outputs. Features 3 enable inputs, 4.5V–5.5V supply, and 50pF load capacitance in 16-pin SOIC. From $0.12, in stock worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- OBSOLETE
- Datasheet
- SN74AHCT138D Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $0.1200(MOQ 1)
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 3-line to 8-line decoding with inverting outputs for active-low applications
- 3 enable inputs (2 active-low, 1 active-high) for cascading and bus expansion
- AHCT logic family: TTL-compatible inputs with CMOS-level outputs, 4.5V–5.5V supply
- High-speed operation with low propagation delay and 8mA output sink current
- 16-pin SOIC package for compact PCB integration
Applications
The SN74AHCT138D is widely used in address decoding for memory and I/O expansion in microprocessor-based systems. It is commonly applied in data routing, multiplexing, and bus demultiplexing circuits where active-low chip-select signals are required. Additional applications include industrial control systems, communication equipment, and any design needing reliable 1-of-8 selection logic.
Specifications
| YTEOL | 0 |
| Additional Feature | 3 ENABLE INPUTS |
| Family | AHCT/VHCT/VT |
| Input Conditioning | STANDARD |
| JESD-30 Code | R-PDSO-G16 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 50pF |
| Logic IC Type | 3-LINE TO 8-LINE DECODER |
| Max I(ol) | 0.008A |
| Number of Bits | 8 |
| Number of Functions | 1 |
| Output Characteristics | 3-STATE |
| Output Polarity | INVERTED |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP16,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TUBE |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 0.04mA |
| Prop. Delay@Nom-Sup | 12ns |
| Propagation Delay (tpd) | 13ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.5V |
| Supply Voltage-Min (Vsup) | 4.5V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | CMOS |
| Temperature Grade | INDUSTRIAL |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Mexico |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the operating voltage range of the SN74AHCT138D?
The SN74AHCT138D operates from a 4.5V to 5.5V supply voltage. It belongs to the AHCT logic family, which accepts TTL-compatible input levels while providing CMOS-level output drive, making it suitable for mixed 3.3V/5V systems.
How do the enable inputs work on the SN74AHCT138D?
The SN74AHCT138D has three enable inputs: two active-low (G1-bar, G2-bar) and one active-high (G3). All three must be in their active state simultaneously for the device to decode. This allows easy cascading of multiple decoders and flexible enable control in complex systems.
What are typical applications for the SN74AHCT138D decoder?
Typical applications include memory address decoding in microcontroller and microprocessor systems, I/O port selection, data demultiplexing, and bus expansion. It is also used in industrial control panels, communication hardware, and multi-device selection circuits where one-of-eight signal routing is needed.
What package does the SN74AHCT138D come in and what are its output specifications?
The SN74AHCT138D is available in a 16-pin SOIC (Small Outline IC) package. Its outputs are inverting (active-low), with a maximum output low current (I_OL) of 8mA and a specified load capacitance of 50pF, supporting reliable signal integrity in high-speed digital designs.
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| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $0.8000 | $0.80 |
| 25+ | $0.6740 | $16.85 |
| 26+ | $0.2400 | $6.24 |
| 168+ | $0.1800 | $30.24 |
| 209+ | $0.1600 | $33.44 |
| 835+ | $0.1200 | $100.20 |
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