LS7211

LSI/CSI UL ® LS7211-7212 (631) 271-0400 FAX (631) 271-0405 June 1997 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 A3800 PROGRAMMABLE DIGITAL DELAY TIMER FEATURES: 8-bit programmable delay from nanoseconds 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 32.768KHz watch crystal Four operating modes Reset input for delay abort Low quiescent and operating current Direct relay drive +4V to +18V operation (VDD-VSS) LS7211/LS7212 (DIP), LS7211-S/LS7212-S (SOIC)-See Figure 1 DESCRIPTION: The LS7211/LS7212 are monolithic 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). 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 TABLE 1. MODE SELECTION A 0 0 1 1 B 0 1 0 1 MODE One-Shot (OS) Delayed Operate (DO) Delayed Release (DR) Dual Delay (DD) A B V DD (+V) RC/CLOCK RCS/CLKS PSCLS RESET V SS (-V) OUT 1 2 3 18 17 16 PIN ASSIGNMENT - TOP VIEW TR...