SN74HCS138QDYYRQ1

Overview

The SN74HCS138QDYYRQ1 is an automotive-qualified, high-speed silicon gate CMOS decoder/demultiplexer featuring Schmitt-trigger inputs. It converts three binary address inputs into one of eight active-low outputs. The device operates within a supply voltage range of 2 V to 6 V and supports an ambient temperature range from -40°C to +125°C. Propagation delays vary between 7 ns and 22 ns depending on voltage and temperature conditions. It utilizes a SOT-23-THIN (16-pin) package.

Feature Summary

• AEC-Q100 qualified for automotive applications with specified temperature grades and ESD protection levels.
• Schmitt-trigger inputs provide noise rejection and tolerance for slow or noisy input signals.
• Low power consumption characteristics include minimal typical supply current and input leakage.
• Balanced push-pull outputs deliver significant drive capability across the operating voltage range.

Applications

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

Procurement Notes

Verify the specific ordering suffix matches the required package type and reel configuration. Confirm that the component meets AEC-Q100 Grade 1 requirements for your target environment. Ensure design compliance with absolute maximum ratings regarding supply voltage and thermal limits during integration.

Selection Notes

Select this component when automotive qualification and low power are critical alongside standard decoding functions. The Schmitt-trigger inputs make it suitable for environments with signal integrity challenges. Verify that the SOT-23-THIN package fits the board space constraints compared to larger alternatives like SOIC or TSSOP.

Part Context

This part belongs to the SN74HCS138-Q1 family of automotive decoders. It shares functional logic with non-automotive variants but includes enhanced reliability testing and qualification standards required for vehicle electronics. The 'Q1' suffix denotes automotive qualification, while 'DYY' specifies the thin small-outline transistor package.

Replacement Considerations

SN74HCS138DYYRQ1

FAQ

How do the strobe inputs affect the decoder operation?

The device has three strobe inputs (G2, G1, and G0). When any of these strobes are in their inactive state, all outputs are forced high. Only when all strobes are active does the decoder enable the selected output to go low based on the address inputs.

What is the purpose of the wettable flanks mentioned in the features?

Wettable flanks improve side solder wetting in QFN packages. This feature facilitates reliable inspection via automatic optical inspection (AOI) by ensuring visible solder fillets on the package sides.