DESCRIPTION:

The LS7215 and LS7216 are CMOS integrated circuits for generating digitally programmable delays. The delay is controlled by 8 binary weighted inputs, WB0 - WB7, in conjunction with an applied clock or oscillator frequency. The programmed time delay manifests itself in the Delay Output (OUT) as a function of the Operating Mode selected by the Mode Select inputs A and B: One-Shot, Delayed Operate, Delayed Release or Dual Delay. The time delay is initiated by a transition at the Trigger Input (TRIG).

FEATURES:

• Programmable delay from microseconds to days

• Programmable delay controlled by 8 binary-weighted delay inputs that can be latched from a shared 8-bit bus

• On chip oscillator (RC or Crystal) or external clock time base

• Selectable prescaler for real time delay generation based on 50Hz/60Hz time base or 32,768Hz watch crystal

• Four operating modes

• Reset input for delay abort

• Low quiescent and operating current

• Direct relay drive

• +3V to +18V operation (VDD - VSS)

• LS7215, LS7216 (DIP); LS7215-S, LS7216-S (SOIC) - See Figure 1 -