LS118-S

Specialized ICS Overview

The LogiSwitch LS118-S is a three-channel switch debouncer IC in an 8-pin narrow SOIC package. It utilizes adaptive NoBounce technology to eliminate contact bounce without external components. The device operates on a supply voltage of 2.5 V to 5.5 V and features a request/acknowledge handshake protocol via NL/HS pins for efficient interrupt handling. Internal debounce time is fixed at 21 ms, with a typical input-to-output propagation delay of 4 µs. Supply current is typically 1.0 mA at 3.0 V.

Specialized ICS Feature Summary

• Adaptive NoBounce technology eliminates switch bounce without external passive components or timing calculations.
• Integrated handshake protocol allows immediate cycle termination via a 5 µs ACK pulse from the host processor.
• Provides immediate output change with no delay on actuation or release, mirroring the switch input minus noise.
• Includes internal pull-up currents (typical 100 µA per pin) and requires no user-provided timing components.

Specialized ICS Applications

• Embedded systems requiring reliable mechanical switch interfacing without polling overhead.
• Interrupt-driven applications where rapid acknowledgment of switch events reduces processor latency.
• Industrial control panels and human-machine interfaces needing robust noise immunity.

Specialized ICS Procurement Notes

Verify the specific suffix 'S' corresponds to the 8-pin narrow SOIC (150 mil) package variant. Confirm that the application design accommodates the fixed 21 ms internal debounce period and the 5 µs acknowledge pulse requirement for the handshake feature. Ensure supply voltage remains within the 2.5 V to 5.5 V range during operation.

Specialized ICS Selection Notes

Select the LS118-S when exactly three independent switch channels are required in a compact surface-mount footprint. Choose this model over the LS119-S or LS120 series if channel count exceeds three. Consider the handshake capability if software efficiency is critical; otherwise, the NL/HS pins function as standard active-high outputs.

Specialized ICS Part Context

The LS118-S belongs to the LS100 Series of Ultra-Fast Response Debounce ICs, which also includes the six-channel LS119 and nine-channel LS120 variants. This series is characterized by its proprietary adaptive logic and handshake protocol, distinguishing it from traditional RC-based or microcontroller-dependent debouncing solutions.

Specialized ICS Replacement Considerations

No direct cross-model replacements are documented. The LS118-P serves as the through-hole equivalent within the same family. Alternative generic debounce ICs may require external components and lack the integrated handshake functionality.

Specialized ICS FAQ

How does the handshake protocol improve system performance?

It allows the host processor to terminate the switch service cycle immediately with a 5 µs ACK pulse, eliminating the need to wait for the full 20 ms clean time or switch release, thus freeing CPU cycles.

What is the internal debounce time for the LS118-S?

The internal debounce time is fixed at 21 ms, regardless of the external switch characteristics or supply voltage within the operating range.

Can the NL/HS pins be used without the handshake feature?

Yes. If the handshake is not utilized, the NL/HS pins function as ordinary active-high outputs that mirror the switch input with bounce removed.