LS7215

Overview

The LS7215 is a CMOS integrated circuit designed for generating digitally programmable time delays. It utilizes eight binary-weighted inputs (WB0-WB7) to set the delay duration, which is controlled by an applied clock or oscillator frequency. The device supports four operating modes: One-Shot, Delayed Operate, Delayed Release, and Dual Delay. It features an on-chip oscillator capable of using RC components, crystals, or external clocks, along with selectable prescalers for real-time generation based on 50Hz/60Hz mains or 32,768Hz watch crystals. The IC operates within a voltage range of +3V to +18V.

Feature Summary

• Digitally programmable delay ranging from microseconds to days via 8-bit binary weighted inputs
• Integrated oscillator support for RC, crystal, or external clock time bases
• Four selectable operating modes including One-Shot and Dual Delay
• Direct relay drive capability with low quiescent current consumption

Applications

• Industrial timing control systems requiring precise digital delay generation
• Automated machinery sequencing and process control loops
• Safety interlock circuits with defined activation or deactivation delays
• Consumer appliances utilizing delayed start or stop functions

Part Context

The LS7215 belongs to the LS721 family of programmable digital delay timers manufactured by LSI Computer Systems. It is functionally similar to the LS7216 but may differ in specific pin configurations or internal logic states. The component is available in DIP and SOIC packages, serving as a discrete solution for timing applications before the widespread adoption of microcontrollers.

Replacement Considerations

The LS7216 is a closely related part within the same family. Verification of pin compatibility and logic polarity differences between the LS7215 and LS7216 is required before substitution. No other direct cross-model substitutes are documented in the provided source material.