Overview
The CD74HC238E is a high-speed CMOS logic 3-to-8 line decoder/demultiplexer produced by Texas Instruments. This device is well-suited for memory address decoding or data routing applications. It contains a single 3:8 decoder and features three address select inputs (A2, A1, and A0) and three strobe inputs (G2, G1, and G0) to simplify cascading and facilitate demultiplexing. The outputs of the CD74HC238E are normally high when selected, making it an inverting decoder/demultiplexer.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package Type | PDIP | |
| Number of Pins | 16 | |
| Operating Temperature Range | -55 to 125 | °C |
| Supply Voltage Range | 2 to 6 | V |
| Propagation Delay (Typical) | 13 | ns (at VCC = 5 V, CL = 15 pF, TA = 25°C) |
| Output Drive (IOL/IOH) (Max) | 5.2/-5.2 | mA |
| ESD HBM | 2 | kV |
| ICC @ Nom Voltage (Max) | 0.08 | mA |
| Bandwidth | 28 | MHz |
Key Features
- Select one of eight data outputs: Active high for '238.
- I/O port or memory selector.
- Three enable inputs to simplify cascading and facilitate demultiplexing.
- Wide operating temperature range: -55°C to 125°C.
- Balanced propagation delay and transition times.
- Significant power reduction compared to LSTTL logic ICs.
- High noise immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5 V.
- CMOS input compatibility, Il ≤ 1µA at VOL, VOH.
Applications
- Memory address decoding.
- Data routing applications.
- I/O port selection.
- Demultiplexing functions.
- General logic applications requiring decoding or demultiplexing.
Q & A
- What is the primary function of the CD74HC238E?
The CD74HC238E is a 3-to-8 line decoder/demultiplexer, used for selecting one of eight data outputs based on three address inputs and three strobe inputs.
- What are the operating voltage ranges for the CD74HC238E?
The device operates within a supply voltage range of 2 to 6 volts.
- What is the typical propagation delay of the CD74HC238E?
The typical propagation delay is 13 ns at VCC = 5 V, CL = 15 pF, and TA = 25°C.
- What are the output drive capabilities of the CD74HC238E?
The output drive capability is up to 5.2 mA for both IOL and IOH.
- What is the ESD HBM rating for the CD74HC238E?
The ESD HBM rating is 2 kV.
- What is the maximum ICC at nominal voltage for the CD74HC238E?
The maximum ICC at nominal voltage is 0.08 mA.
- What are the common applications of the CD74HC238E?
Common applications include memory address decoding, data routing, I/O port selection, and demultiplexing functions.
- What is the operating temperature range of the CD74HC238E?
The operating temperature range is -55°C to 125°C.
- How does the CD74HC238E handle noise immunity?
The device has high noise immunity with NIL = 30% and NIH = 30% of VCC at VCC = 5 V.
- What are the package options available for the CD74HC238E?
Package options include PDIP, SOIC, SOP, and TSSOP.
- Is the CD74HC238E suitable for new designs?
Yes, the CD74HC238E is recommended for new designs and has an active lifecycle status.
