Product Overview
High-speed CMOS address decoder - 3-to-8 demultiplexer - active-low outputs - 2.0 to 6.0 V logic
Condition
Single unit available. Condition not specified; appears excellent with nothing out of ordinary. Covered by PartsMine Satisfaction Guarantee. Evaluation: Visual inspection only. Function testing not performed. Sourced from an electronics distributor that was consolidating inventory.
Ships same business day from Idaho. Packed carefully.
Product Overview
Harris Semiconductor CD74HC138E 3-to-8 line decoder/demultiplexer in a 16-pin PDIP through-hole package. Commonly used for address decoding and chip-select routing where one of eight outputs is selected by a 3-bit input code.
Key Features
- Logic function: 3-to-8 line decoder / demultiplexer
- Output type: Inverting, active-low outputs
- Package: 16-pin PDIP (through-hole DIP-16)
- Supply voltage range: 2.0 V to 6.0 V
- Propagation delay: typically 9 ns to 15 ns at 5 V
- Enable pins: three enables (two active-low, one active-high) for cascading
- Operating temperature: -55 C to 125 C
Applications
- Memory address decoding and peripheral chip-select routing
- Digital demultiplexing and data routing in control and telecom boards
- Retro-computing repairs and legacy logic systems using 74HC devices
Frequently Asked Questions
Are the outputs active-high or active-low?
Active-low. The selected output goes low when addressed.
Will this work in a strict 5 V TTL input system?
Not always. This is an HC (CMOS-threshold) part. If you need direct TTL-threshold compatibility, the HCT138 variant is typically used.
What supply voltage does it run on?
2.0 V to 6.0 V DC.
Is this surface-mount or through-hole?
Through-hole. The CD74HC138E is the 16-pin PDIP package.
