LS7216

Overview

The LS7216 is a CMOS integrated circuit designed for generating digitally programmable time delays. It utilizes eight binary-weighted inputs (WB0-WB7) to control the delay duration, which is determined by an applied clock or oscillator frequency. The device supports multiple operating modes including One-Shot, Delayed Operate, Delayed Release, and Dual Delay, with the output state managed via Mode Select inputs A and B. Triggering occurs through a transition at the TRIG input, while a dedicated Reset input allows for immediate delay abort. The component operates within a supply voltage range of +3V to +18V.

Feature Summary

• Digitally programmable delay ranging from microseconds to days using 8 binary-weighted inputs
• Four selectable operating modes: One-Shot, Delayed Operate, Delayed Release, and Dual Delay
• Flexible timing base options including on-chip RC/crystal oscillator, external clock, or 50Hz/60Hz prescaler
• Direct relay drive capability with low quiescent current consumption

Applications

• Industrial process control timing sequences
• Automotive ignition and lighting delay circuits
• Consumer appliance timer functions
• Security system arming/disarming delays

Procurement Notes

Verify package availability as the LS7216 is offered in both DIP and SOIC configurations. Confirm that the specific variant meets the required voltage and temperature specifications for the target application environment. Ensure compatibility with existing bus architectures if latching delay values from an 8-bit bus is intended.

Selection Notes

Select the LS7216 when a wide dynamic range of delay times is required without complex external components. Choose this part over discrete solutions for applications needing direct relay driving capabilities. Consider the LS7215 if pinout or specific mode implementations differ slightly for the design constraints. Evaluate power supply stability given the +3V to +18V operational range.

Part Context

The LS7216 belongs to the LS721x family of programmable digital delay timers manufactured by LSI Computer Systems. This series includes variants such as the LS7210, LS7211, and LS7215, which share similar core functionalities but may differ in pin counts, package types, or specific feature sets. The family is designed for general-purpose timing applications requiring reliable, long-duration delays.

Replacement Considerations

Cross-reference with LS7215 for potential functional equivalence, noting any differences in package or specific mode support. Verify pin-to-pin compatibility before substitution to ensure proper integration into existing PCB layouts.