Overview
The SN74AHC138DRE4 is a 3-line to 8-line decoder/demultiplexer produced by Texas Instruments. This device is designed for high-performance memory-decoding and data-routing applications that require very short propagation-delay times. It is particularly useful in high-speed memory systems where it can minimize the effects of system decoding. When used with high-speed memories and a fast enable circuit, the delay times of the decoder and the memory's enable time are typically less than the memory's access time, making the system delay introduced by the decoder negligible.
Key Specifications
| Parameter | Min | Max | Unit |
|---|---|---|---|
| VCC Supply Voltage Range | 2 | 5.5 | V |
| VI Input Voltage Range | -0.5 | 7 | V |
| VO Output Voltage Range | -0.5 | VCC + 0.5 | V |
| TA Operating Free-Air Temperature Range | -40 | 85 | °C |
| tPLH Propagation Delay Time (A, B, C to Y) | 5.7 | 9.5 | ns |
| tPHL Propagation Delay Time (A, B, C to Y) | 5.7 | 9.5 | ns |
| IOH High-Level Output Current | -8 | -50 | mA |
| IOL Low-Level Output Current | 8 | 50 | mA |
| ESD Protection (Human-Body Model) | 2000 | V | |
| ESD Protection (Charged-Device Model) | 1000 | V |
Key Features
- Operating voltage range: 2V to 5.5V VCC
- Designed specifically for high-speed memory decoders and data-transmission systems
- Incorporate three enable inputs to simplify cascading and/or data reception
- Latch-up performance exceeds 250mA per JESD 17
- ESD protection exceeds JESD 22: 2000V Human-Body Model and 1000V Charged-Device Model
- Active low outputs; the selected output is pulled LOW, while the remaining outputs are all HIGH
- Low power consumption, with a typical ICC of 80-µA maximum
- Typical propagation delay time (tpd) of 15 ns
- ±4-mA output drive at 5 V
- Low input current of 1-µA maximum
Applications
- LED Displays
- Servers
- White Goods
- Power Infrastructure
- Building Automation
- Factory Automation
Q & A
- What is the operating voltage range of the SN74AHC138DRE4?
The operating voltage range is 2V to 5.5V VCC
- What are the primary applications of the SN74AHC138DRE4?
The device is used in high-performance memory-decoding and data-routing applications, including LED displays, servers, white goods, power infrastructure, building automation, and factory automation
- How many enable inputs does the SN74AHC138DRE4 have?
The device has three enable inputs: two active-low and one active-high
- What is the typical propagation delay time of the SN74AHC138DRE4?
The typical propagation delay time (tpd) is around 15 ns
- Does the SN74AHC138DRE4 have ESD protection?
Yes, it exceeds JESD 22 standards with 2000V Human-Body Model and 1000V Charged-Device Model protection
- What is the output configuration of the SN74AHC138DRE4?
The selected output is pulled LOW, while the remaining outputs are all HIGH
- What are the package options available for the SN74AHC138DRE4?
Available packages include SOIC, SSOP, PDIP, SOP, TSSOP, TVSOP, and VQFN
- Is the SN74AHC138DRE4 scheduled for obsolescence?
Yes, it is scheduled for obsolescence and will be discontinued by the manufacturer
- What is the maximum output current of the SN74AHC138DRE4?
The maximum output current is ±25 mA
- What is the thermal resistance of the SN74AHC138DRE4?
The junction-to-ambient thermal resistance varies by package, but for example, the RGY (VQFN) package has a thermal resistance of around 60-70°C/W
