SN74AHC138QWBQBRQ1

Signal Switches, Multiplexers, Decoders Overview

The SN74AHC138QWBQBRQ1 is an automotive-grade 3-to-8 decoder and demultiplexer from Texas Instruments. It operates within a supply voltage range of 2V to 5.5V and supports junction temperatures from -40°C to +125°C. The device features balanced CMOS push-pull outputs with low propagation delay, typically 10.5ns at 5V with a 50pF load. It includes three address inputs (A0, A1, A2) and three enable/strobe inputs (G0, G1, G2). The component is housed in a 16-pin WQFN package with wettable flanks.

Signal Switches, Multiplexers, Decoders Feature Summary

• AEC-Q100 qualified for automotive applications with specified temperature grades and ESD protection levels.
• Features balanced CMOS push-pull outputs capable of sourcing and sinking similar currents.
• Includes wettable flank technology on the QFN package to improve side soldering and facilitate automatic optical inspection.
• Provides standard CMOS inputs requiring fast signal transitions to prevent oscillation and excessive power consumption.

Signal Switches, Multiplexers, Decoders Applications

• Memory device selection with shared data bus
• Reducing required number of outputs for chip select applications
• Routing data

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific ordering suffix matches the required package type and lead time requirements. Confirm that the device meets the necessary AEC-Q100 qualification standards for your specific automotive application environment. Ensure compatibility with your system's voltage levels and thermal management constraints before finalizing procurement decisions.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when an automotive-qualified 3-to-8 decoding function is required. Consider the WQFN package with wettable flanks if automated optical inspection reliability is a priority. Ensure the design accommodates the recommended input transition rates and output capacitive loads to maintain performance specifications across the full operating temperature range.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to the SN74AHC138-Q1 family of automotive decoders. It shares functional characteristics with other members of the series but is distinguished by its specific packaging and qualification status. The device is designed for high-reliability applications where robust logic decoding is essential under varying automotive electrical conditions.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Direct replacements include other SN74AHC138-Q1 variants with different packages, such as the SN74AHC138QPWRQ1 in TSSOP-16. Verify pinout compatibility and ensure the substitute maintains the same AEC-Q100 qualification and electrical characteristics for seamless integration.

Signal Switches, Multiplexers, Decoders FAQ

How are unused inputs handled in this device?

Unused standard CMOS inputs must not be left floating. They should be terminated to VCC or ground, potentially using a pull-up or pull-down resistor, to prevent undefined operational states and excessive power consumption.

What is the purpose of the wettable flanks on the package?

Wettable flanks improve side wetting after soldering, creating a reliable side fillet. This feature makes the QFN package easier to inspect using automatic optical inspection (AOI) systems.