DESCRIPTION:

The LS7211N and LS7212N 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 of the Trigger Input (TRIG).

FEATURES:

• 8-bit programmable delay from microseconds to days

• 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)

• LS7211N, LS7212N (DIP); LS7211N-S, LS7212N-S(SOIC)  - See Figure 1-