SN74HC138DRG4

Overview

The SN74HC138DRG4 is a 3-to-8 decoder and demultiplexer manufactured by Texas Instruments. It operates within a supply voltage range of 2 V to 6 V and features active-low outputs. The device incorporates three enable inputs (one active-high, two active-low) to facilitate cascading or data reception. It utilizes SOIC-16 surface-mount packaging with a body size of 9.90 mm x 3.90 mm. Electrical characteristics include a maximum propagation delay of 45 ns at 4.5 V and a typical power consumption of 80 µA.

Feature Summary

• Designed for high-speed memory decoding and data transmission systems requiring short propagation delays.
• Outputs can drive up to 10 LSTTL loads while maintaining low input current.
• Three enable inputs simplify cascading configurations without external inverters.

Applications

• LED Displays
• Servers
• White Goods

Procurement Notes

Verify the specific ordering suffix 'G4' against the manufacturer's latest documentation to confirm RoHS compliance and lead finish specifications. Confirm that the SOIC-16 package dimensions match the design footprint requirements. Ensure the component status is reviewed as availability may change over time.

Selection Notes

Select this component when a 3-to-8 decoding function is required in CMOS logic applications. It is suitable for designs needing balanced output drive capabilities and wide operating voltage flexibility between 2 V and 6 V. Consider the thermal resistance values if operating in enclosed environments.

Part Context

This part belongs to the SNx4HC138 family of decoders and demultiplexers. It is designed for high-performance memory-decoding or data-routing applications where system delay minimization is critical. The device allows effective system delay introduction to be negligible when used with fast enable circuits in high-speed memories.

Replacement Considerations

SN74HC138DR

FAQ

How are the enable inputs configured?

The device has three enable inputs: one active-high (G1) and two active-low (G2A, G2B). All three must be active for the outputs to be enabled.

What is the state of unselected outputs?

When an output is selected, it is pulled LOW. The remaining unselected outputs remain HIGH.