MC74AC138MG

Overview

The MC74AC138MG is a high-speed 1-of-8 decoder/demultiplexer manufactured by onsemi. It accepts three binary weighted inputs (A0, A1, A2) and provides eight mutually exclusive active-LOW outputs (O0-O7). The device operates within a supply voltage range of 2.0 V to 6.0 V and supports an operating ambient temperature from -40°C to +85°C. It features three enable inputs: two active-LOW (E1, E2) and one active-HIGH (E3). Outputs can source or sink up to 24 mA. The component is housed in a 16-pin EIAJ package.

Feature Summary

• Demultiplexing capability using active LOW enable inputs as data inputs
• Multiple input enables allow parallel expansion to larger decoders
• Active LOW mutually exclusive outputs ensure precise signal selection

Applications

• High-speed bipolar memory chip select address decoding
• Parallel expansion to 1-of-24 or 1-of-32 decoders
• General-purpose demultiplexing applications

Procurement Notes

Verify the specific ordering suffix 'MG' against official manufacturer documentation to confirm the exact package type and availability status. Ensure that the selected variant meets all required electrical specifications for your application environment. Cross-reference with authorized distributors to validate current production status and lead times.

Selection Notes

Select this component when a high-speed 1-of-8 decoding function is required within a wide voltage range. Consider the EIAJ-16 package constraints for board layout. Verify compatibility with system logic levels and ensure adequate thermal management for the intended operating temperature range.

Part Context

This part belongs to the MC74AC138/74ACT138 family of 1-of-8 decoder/demultiplexers. The AC series offers a wider operating voltage range compared to the ACT series, which features TTL-compatible inputs. This specific model utilizes the EIAJ-16 package format, distinguishing it from other variants like PDIP or SOIC.

Replacement Considerations

MC74AC138M

FAQ

How does the MC74AC138MG support decoder expansion?

The multiple input enables allow parallel expansion to a 1-of-24 decoder using three devices or a 1-of-32 decoder using four devices and one inverter.

What are the enable input configurations?

The device has three enable inputs: two active-LOW (E1, E2) and one active-HIGH (E3). All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH.