LS7212N Datasheet | LSI

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 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). PIN ASSIGNMENT - TOP VIEW A1 B V DD (+V) 2 3 RC/CLOCK 4 RCS/CLKS PSCLS 5 6 RESET 7 V SS (-V) OUT 8 9 LS7211N 18 TRIG 17 WB0 16 WB1 15 WB2 14 WB3 13 WB4 12 WB5 11 WB6 10 WB7 A1 B2 18 TRIG 17 WB0 I/O DESCRIPTION : MODE SELECT Inputs A & B (Pins 1 & 2) The 4 operating modes are selected by Inputs A and B according to Table 1 V DD (+V) 3 XTLI/CLOCK XTLO 4 5 16 WB1 15 WB2 14 WB3 TABLE 1. MODE SELECTION A B MODE 0 0 One-Shot (OS) 0 1 Delayed Operate (DO) 1 0 Delayed Release (DR) 1 1 Dual Delay...