TC74HC138AFN(F,M)

Overview

The TC74HC138AFN(F,M) is a high-speed CMOS 3-to-8 line decoder fabricated with silicon gate C2MOS technology. It provides inverted outputs (0Y to 7Y) and features three binary select inputs (A, B, C) alongside three enable inputs (G1, 2AG, 2BG). The device operates within a supply voltage range of 2 V to 6 V and supports an operating temperature from -40°C to 85°C. Propagation delay is typically 16 ns at 5 V with a 15 pF load, while quiescent current is maximized at 4 μA at 25°C.

Feature Summary

• High-speed operation comparable to equivalent LSTTL devices while maintaining low power dissipation
• Symmetrical output impedance with drive capability for 10 LSTTL loads
• Wide operating voltage range supporting 2 V to 6 V supply levels
• Pin and function compatibility with standard 74LS138 logic families

Applications

• Address decoding for memory systems
• General electronics applications including computers and office equipment
• Industrial robots and measuring equipment
• Home electronics appliances

Procurement Notes

Verify the specific suffix against the manufacturer's documentation to confirm package type and regional availability. The AFN variant is noted as unavailable in Japan. Confirm RoHS compliance status directly with Toshiba Semiconductor and Storage representatives prior to procurement, as environmental declarations are subject to change.

Selection Notes

Select this component when pin-compatible replacement for 74LS138 is required in CMOS designs. Ensure the application voltage falls between 2 V and 6 V. Verify that the load capacitance does not exceed specifications to maintain propagation delay targets. Unused inputs must be tied to VCC or GND to ensure normal operation.

Part Context

This part belongs to the TC74HC138A series of 3-to-8 line decoders manufactured by Toshiba Semiconductor and Storage. It utilizes silicon gate C2MOS technology to achieve high speed and low power consumption. The family includes DIP, SOP, and SOL packages, offering flexibility for through-hole and surface-mount assembly requirements.

Replacement Considerations

The datasheet explicitly states pin and function compatibility with the 74LS138. No other substitute part numbers are documented in the provided source material.