SN74HCS238PWR

Overview

The SN74HCS238PWR is a 16-pin TSSOP decoder/demultiplexer from the HCS logic series. It operates on a supply voltage of 2 V to 6 V with an ambient temperature range of -40°C to +125°C. The device features Schmitt-trigger inputs and balanced CMOS push-pull outputs capable of ±7.8 mA drive at 6 V. Propagation delay ranges from 7 ns to 54 ns depending on voltage and temperature.

Feature Summary

• Schmitt-trigger inputs provide noise rejection for slow or noisy signals
• Balanced CMOS push-pull outputs support high current drive capabilities
• Three strobe inputs facilitate cascading and demultiplexing functions

Applications

• Memory device selection with shared data bus
• Chip select applications to reduce required output count
• Data routing in digital systems

Procurement Notes

Verify the package type matches the design requirements, as the SN74HCS238 family includes SOIC, WQFN, and SOT-23 variants. Confirm that the specific ordering suffix corresponds to the TSSOP-16 package intended for surface mount assembly. Ensure input termination guidelines are followed to prevent undefined states.

Selection Notes

Select this component when noise immunity is critical due to its Schmitt-trigger architecture. It is suitable for memory addressing where binary encoded inputs activate single outputs. Consider the propagation delay specifications relative to system timing requirements and verify thermal dissipation needs based on load conditions.

Part Context

This part belongs to the SN74HCS238 family of 3-to-8 line decoders manufactured by Texas Instruments. The HCS series combines high-speed CMOS performance with Schmitt-trigger inputs. The PW suffix specifically denotes the thin shrink small-outline (TSSOP) package variant within this product line.

Replacement Considerations

SN74HCS238DYYR

FAQ

How do unused inputs affect power consumption?

Unlike standard CMOS, holding Schmitt-trigger inputs at valid values does not cause huge increases in power consumption, though they should be terminated to VCC or ground.

What is the function of the G0, G1, and G2 pins?

These are strobe inputs used to enable or disable the outputs. When any strobe is active, all outputs are forced low; otherwise, the selected output goes high.